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Functional amino acids in nutrition and health

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Abstract

The recent years have witnessed growing interest in biochemistry, physiology and nutrition of amino acids (AA) in growth, health and disease of humans and other animals. This results from the discoveries of AA in cell signaling involving protein kinases, G protein-coupled receptors, and gaseous molecules (i.e., NO, CO and H2S). In addition, nutritional studies have shown that dietary supplementation with several AA (e.g., arginine, glutamine, glutamate, leucine, and proline) modulates gene expression, enhances growth of the small intestine and skeletal muscle, or reduces excessive body fat. These seminal findings led to the new concept of functional AA, which are defined as those AA that participate in and regulate key metabolic pathways to improve health, survival, growth, development, lactation, and reproduction of the organisms. Functional AA hold great promise in prevention and treatment of metabolic diseases (e.g., obesity, diabetes, and cardiovascular disorders), intrauterine growth restriction, infertility, intestinal and neurological dysfunction, and infectious disease (including viral infections).

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... The primary metabolic pathways that improve an organism's growth, health, development, reproduction, and survival are regulated by FAAs. In human nutrition, arginine, aspartate, cysteine, methionine, leucine, tryptophan, glutamic acid, tyrosine, glycine, taurine, and proline are classified as FAAs (Wu, 2010(Wu, , 2013 (Table 1). ...
... Ala 3.9 ± 0.6 a 2.6 ± 0.6 b 2.3 ± 0.8 c 3.0 ± 0.2 a 2.07 ± 0.5 c 2.9 ± 0.3 b 2.7 ± 0.4 b 3.6 ± 0.5 a Asp 6.5 ± 1.4 a 4.6 ± 0.3 b 5.2 ± 1.3 b 3.9 ± 0.6 c 3.8 ± 0.7 c 4.5 ± 1.1 b 4.4 ± 0.5 b 6.4 ± 1.5 a Ser 2.5 ± 0.2 a 1.8 ± 0.4 b 2.0 ± 0.3 a 1.6 ± 0.1 c 1.5 ± 0.5 c 1.7 ± 0.6 b 1.7 ± 0.6 b 2.4 ± 0.6 a Classification of amino acids as nutritionally "essential, " "nonessential, " or "conditionally essential" is as per Wu (2013). # Conditionally essential amino acids; † Functional amino acids as per human nutrition (Wu, 2010(Wu, , 2013. ...
... Ala 3.9 ± 0.6 a 2.6 ± 0.6 b 2.3 ± 0.8 c 3.0 ± 0.2 a 2.07 ± 0.5 c 2.9 ± 0.3 b 2.7 ± 0.4 b 3.6 ± 0.5 a Asp 6.5 ± 1.4 a 4.6 ± 0.3 b 5.2 ± 1.3 b 3.9 ± 0.6 c 3.8 ± 0.7 c 4.5 ± 1.1 b 4.4 ± 0.5 b 6.4 ± 1.5 a Ser 2.5 ± 0.2 a 1.8 ± 0.4 b 2.0 ± 0.3 a 1.6 ± 0.1 c 1.5 ± 0.5 c 1.7 ± 0.6 b 1.7 ± 0.6 b 2.4 ± 0.6 a Classification of amino acids as nutritionally "essential, " "nonessential, " or "conditionally essential" is as per Wu (2013). # Conditionally essential amino acids; † Functional amino acids as per human nutrition (Wu, 2010(Wu, , 2013. Values are reported as mean ± standard deviation (n = 3). ...
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Introduction Proteins and amino acids, as vital biomolecules, are not only part of key metabolic pathways in the body but are also essential for tissue repair, enzyme function, and hormone regulation. They also serve as building blocks for the formation of signaling molecules, such as neurotransmitters and catecholamines. Additionally, amino acids are the primary building components of proteins. Fish serves as a vital source of high-quality animal protein and amino acids, playing a crucial role in supporting human nutrition. Methods High-performance liquid chromatography (HPLC) using fluorescence detector was employed to investigated the amino acid content of eight food fishes from diverse aquatic habitats. Results The study revealed that the small indigenous fish (SIF) Systomus sarana and the marine fish Sardinella melanura were rich sources of all essential amino acids. Furthermore, estuarine fish like Pisodonophis boro can be recommended for specific amino acids like arginine, histidine, leucine, and valine, while Setipinna phasa is suggested for cysteine. Discussion These recommendations rely on the possible contribution of these fishes to the Recommended Dietary Allowance (RDA) regarding each nutrient. The insights gained from this study could be utilized as recommendations to meet amino acid requirement using fish as a natural supplement.
... et al., 2011; Rezaei et al., 2013;Wang et al., 2013;Wu, 2009Wu, , 2013. Functional amino acids include arginine, aspartate, cysteine, glutamine, glycine, histidine, leucine, methionine, proline, threonine, tryptophan, and tyrosine(Mohanty et al., 2014;Wu, 2009Wu, , 2013Notably, this study found that Asian seabass muscle tissue contained all functional amino acids except tryptophan. ...
... et al., 2011; Rezaei et al., 2013;Wang et al., 2013;Wu, 2009Wu, , 2013. Functional amino acids include arginine, aspartate, cysteine, glutamine, glycine, histidine, leucine, methionine, proline, threonine, tryptophan, and tyrosine(Mohanty et al., 2014;Wu, 2009Wu, , 2013Notably, this study found that Asian seabass muscle tissue contained all functional amino acids except tryptophan. ...
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Lates calcarifer, known as Asian seabass, is a brackish-water teleost species within the order Carangiformes, native to the Indo-Pacific region. In Bangladesh, this species is found in natural habitats and cultivated on a small scale in the southern coastal region, particularly in the Khulna-Satkhira area. This study analyzed the nutritional composition of cultured Asian seabass in two different size categories, 512.06 ± 14.5 g and 1003.5 ± 36.64 g, collected from this region. Our findings revealed significant differences in the proximate compositions of the two size groups, except ash content (independent t-test, p < 0.05). The smaller size group had a notably higher moisture content (74.96 ± 0.04%), whereas the larger fish exhibited significantly greater protein and fat contents (20.48 ± 0.1% and 5.34 ± 0.18%, respectively). Fatty acid analysis showed distinct differences as well; the larger size group contained higher concentrations of saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs), while the smaller fish was richer in polyunsaturated fatty acids (PUFAs). Among the SFAs and omega-3 PUFAs, undecanoic acid and α-linolenic acid were the most prevalent in both groups. However, MUFA profiles differed: palmitoleic acid was dominant in the smaller size group, while oleic acid was more abundant in the larger size group. All essential amino acids (EAAs), except tryptophan, were detected in both groups, with lysine being the most prominent, measuring 5.53±0.44 g/100 g dry weight in smaller size group and 3.91±0.32 g/100 g dry weight in larger size group. Notably, the smaller size group demonstrated a significantly higher overall concentration of EAAs. Overall, this study highlights the nutritional richness of cultured Asian seabass, particularly in terms of fatty acid and amino acid profiles. The superior concentrations of essential amino acids, a higher EPA/DHA ratio, and a more favorable n-3/n-6 ratio in the smaller fish suggest it as a nutritionally superior and well-balanced fish option.
... These include phenylalanine, leucine, isoleucine, lysine, methionine, threonine, tryptophan, valine, and histidine. Essential amino acids are essential for building proteins, transmitting cellular signals, controlling gene activity, and regulating crucial metabolic processes that improve general wellbeing, facilitate growth, support development and promote reproductive health (Wu 2013, Ling et al. 2023. This indicates that the seed of B. aegyptiaca would have therapeutic values to be explored for the well-being of the population. ...
... This reinforces our idea that seed oil is nutritional. The work of Wu (2013) showed that amino acid imbalances or deficiencies can have significant consequences on health. For example, arginine deficiency can negatively impact sperm quality and embryo/fetal survival, even if nitrogen balance is maintained. ...
Article
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Balanites aegyptiaca fruits come in various shapes, which can be beneficial for breeding and industrial production purposes. This study aimed to estimate the morphological and biochemical variability of the fruit and seed kernel of B. aegyptiaca based on their shape. Six shapes, namely BLS (big long sharp), BSR (big sharp round), SLR (small long round), BSH (big short hollow), BLR (big long round) and SSR (small short round), were collected. The length, width and thickness of fruits/seeds and the weight of 100 fruits were assessed using a caliper and a scale. Physicochemical properties were determined using official AOAC and AOCS methods. The fatty acids were determined according to the methods of the IUPAC standards. Amino acids were analyzed using the non-derivatization LC-MS/MS method. Mineral and trace element analyses were conducted using inductively coupled plasma emission spectrometry ICP-OES. The results showed significant differences (P<0.001) in the length, width, thickness and weight of 100 fruits across the shapes. The BSH shape had the highest crude fat content and energy value, while the BLS shape had the least favorable profile due to high moisture and acid index. Seventeen fatty acids, 18 amino acids, and 23 minerals were identified, with significant variations observed among the shapes. The predominant fatty acid was cis-9,12-linoleic acid, ranging from 295458.09±100 mg/kg (BLS) to 194138.63±39 mg/kg (BLR). The BLS shape was characterized by the presence of cis-9,12,15-linolenic acid and stearic acid. Cystine was the most abundant amino acid ranging from 615418.83±29 mg/kg (BSR) to 339480.67±81 mg/kg (SSR). Potassium was the most prevalent mineral, followed by phosphorus, calcium, and magnesium. The BLS shape was particularly rich in various minerals. These results highlight the significant morphological and biochemical variability of B. aegyptiaca in fruit, seed and kernel variants.
... Многие исследования показали, что asp играет важную роль в физиологических процессах печени [2], [17]. asp необходим для синтеза пуринов, пиримидина, аспарагина и аргинина, а также участвует в синтезе инозитола и бета-аланина [17]. ...
... Многие исследования показали, что asp играет важную роль в физиологических процессах печени [2], [17]. asp необходим для синтеза пуринов, пиримидина, аспарагина и аргинина, а также участвует в синтезе инозитола и бета-аланина [17]. Есть мнение, что пищевые добавки asp подавляют атеросклероз и могут ингибировать развитие стеатоза и фиброза печени, а также могут облегчить повреждение печени за счет подавления экспрессии провоспалительных медиаторов [2], [18]. ...
Conference Paper
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Glycine, Gamma-aminobutyric acid (GABA), Glutamate, and Aspartate are neurotransmitter amino acids. It was examined 24 patients with chronic hepatopathy: 12 patients with chronic HBV infection (group I) and 12 patients with hepatic steatosis (group II), the control group (CG) consisted of 12 practically healthy individuals. Quantitative determination of Aspartate, Glutamate, Glycine and GABA in blood serum was carried out using liquid chromatography. In I-st group of patients the level of Glycine was 18.76±1.45, GABA-0.83±0.06, Aspartate-5.56±0.97, and Glutamate-6.34±0.70 mcM/dL. In II-nd group: the level of Glycine was 22.37±0.91, GABA-0.77±0.03, Aspartate-5.16±0.74, and Glutamate-7.87±1.47 mcM/dL. In CG: the level of Glycine y was 22.93±2.21, GABA-0.55±0.06, Aspartate-2.69±0.45, and Glutamate-12.46±1.92 mcM/dL. A violation of neurotransmitter amino acids metabolism is found in chronic hepatopathy. A decrease in glycine and glutamate was observed in patient's blood serum, with an increase in GABA and aspartate. These disorders are most profound in individuals with chronic viral infection B.
... Diverse studii au arătat că asp joacă un rol important în procesele fiziologice ale ficatului [10,16]. asp este esențial pentru sinteza purinei, pirimidinei, asparaginei şi argininei şi este implicat în sinteza inozitolului şi beta-alaninei [16]. ...
... Diverse studii au arătat că asp joacă un rol important în procesele fiziologice ale ficatului [10,16]. asp este esențial pentru sinteza purinei, pirimidinei, asparaginei şi argininei şi este implicat în sinteza inozitolului şi beta-alaninei [16]. S-a raportat că introducerea suplimentară de asp în alimentație are capacitatea de a suprima ateroscleroza şi poate împiedica dezvoltarea steatozei şi fibrozei hepatice, contribuind la atenuarea deteriorării ficatului prin suprimarea expresiei mediatorilor proinflamatori [10,18]. ...
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Introduction. Some amino acids are neurotransmitters. These include glycine (Gly), gamma-aminobutyric acid (GABA), glutamate (Glu), and aspartate (Asp). The liver is an important organ for the metabolism of amino acids. Materials and methods. It was examined 24 patients with chronic hepatopathy: 12 patients with chronic HBV infection (group I) and 12 patients with hepatic steatosis (group II), the control group (CG) consisted of 12 practically healthy individuals. Quantitative determination of Asp, Glu, Gly and GABA in blood serum was carried out using liquid chromatography. Results. In most patients with chronic hepatopathy Gly and Asp levels were within the regional norms, GABA levels were higher, and Glu levels were below the reference values. In I-st group of patients the level of Gly was 18.76±1.45, GABA - 0.83±0.06, Asp - 5.56±0.97, and Glu - 6.34±0.70 mcM/ dL. In II-nd group: the level of Gly was 22.37±0.91, GABA 0.77±0.03, Asp - 5.16±0.74, and Glu - 7.87±1.47 mcM/dL. In CG: the level of Gly was 22.93±2.21, GABA - 0.55±0.06, Asp - 2.69±0.45, and Glu - 12.46±1.92 mcM/dL. Conclusion. A violation of neurotransmitter amino acids metabolism is found in chronic hepatopathy. A decrease in glycine and glutamate was observed in patients’ blood serum, with an increase in GABA and aspartate. These disorders are most profound in individuals with chronic viral infection B.
... In terms of the nutritive value of the fish for human consumption, the comparable (Blackwater trial) or slightly higher (Pennask trial) EAA : NEAA ratio of fish in the Mysis25 and Mysis50 treatments relative to fish in the commercial feed treatments suggests that Mysis-fed fish would be an equally effective source of EAAs, which are important to human health [50]. In addition, the tissue content of four amino acids considered conditionally essential and important to human and mammalian health (glutamic acid, glutamine, glycine, and proline) [50] in Mysis-fed trout was comparable to that in the commercial feed treatment in both trials. ...
... In terms of the nutritive value of the fish for human consumption, the comparable (Blackwater trial) or slightly higher (Pennask trial) EAA : NEAA ratio of fish in the Mysis25 and Mysis50 treatments relative to fish in the commercial feed treatments suggests that Mysis-fed fish would be an equally effective source of EAAs, which are important to human health [50]. In addition, the tissue content of four amino acids considered conditionally essential and important to human and mammalian health (glutamic acid, glutamine, glycine, and proline) [50] in Mysis-fed trout was comparable to that in the commercial feed treatment in both trials. The n-3 : n-6 ratios (3. ...
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The present study explored the potential of wild Mysis diluviana, a widespread freshwater crustacean that is also invasive in many lakes, to serve as a substitute for fishmeal in the formulation of salmonid aquafeed. M. diluviana, harvested from Okanagan Lake in British Columbia, Canada, had a high protein content, with crude protein making up 53% of its dry body weight; lipids formed 32% of dry M. diluviana body weight. Fingerlings from two distinct strains of rainbow trout were fed for 60 days with one of three diet treatments: experimental feeds in which 25% or 50% of the fishmeal ingredient was replaced with M. diluviana and a feed containing no M. diluviana. Feeds containing M. diluviana supported the same survivorship and similar or better fingerling growth as the fishmeal-only feed, including fingerlings of a trout strain that are highly selective feeders. The amino acid and fatty acid composition of fingerling tissues at the end of the experiment was mostly indistinguishable among the three feed treatments. In addition, the tissue composition of fingerlings, such as the EAA : NEAA ratio and the amounts of SFA, MUFA, and PUFA, did not fully match the biochemical composition of their feeds, likely due in part to the capacity of freshwater salmonids for bioconversion of some amino acids into other less available amino acids. M. diluviana was therefore found to be an effective source of protein and lipid for fingerling rainbow trout and an effective substitute for marine fishmeal in trout aquafeed.
... Lysine is a basic amino acid, and most higher animals cannot synthesize lysine [8]. Therefore, lysine is an essential amino acid that must be ingested in sufficient quantities from the diet to maintain protein synthesis [9]. ...
... The values of I/I0 for L-Lys were 16.89, 21.08, 17.60, and 29.23, respectively. In contrast, His and Trp exhibited values between 3.0 and 5.0, while the remaining amino acids ranged between 0. 8 Table S1 of the Supplementary Materials. The fluorescence emission spectrum of the (L,R)-1 blank group is shown in Figure S5. ...
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Lysine plays a crucial role in promoting development, enhancing immune function, and improving the function of central nervous system tissues. The two configurational isomers of amino acids have significantly different effects. Currently, methods for chiral recognition of lysine have been reported; however, previous detection methods have drawbacks such as expensive equipment and complicated detection processes. Fluorescence analysis, on the other hand, boasts high sensitivity, strong selectivity, and simple operation. In this study, we synthesized four novel Binaphthyl-Amine (BINAM)-based fluorescent probes capable of specifically identifying the L-configuration of lysine among the twenty amino acids that constitute human proteins. The enantiomeric fluorescence enhancement ratio (ef or ΔIL/ΔID) reached up to 15.29, demonstrating high enantioselectivity. In addition, we assessed the probe’s recognition capabilities under varying pH levels, reaction times, and metal ion conditions, along with its limit of detection (LOD) and quantum yield. Our results suggest that this probe serves as a highly stable tool for the detection of chiral lysine.
... Proteins found in fish possess unique functional properties that make them ideal as carriers of lipids, creating stable lipid emulsions, forming solid gels, and retaining water (Lee et al., 2016). The essential amino acids like arginine, histidine, tyrosine, isoleucine, cystine, lysine, leucine, threonine, methionine, and tryptophan, as well as nonessential amino acids such as glutamine, glutamic acid, glycine, proline, and taurine, make up the protein of the FPC (Wu, 2010 (Wu, 2013). Fish protein concentrate is highly valued for its collagen content, which provides skin-tightening and whitening benefits, promotes skin cell renewal, strengthens bones, and slows down the aging process. ...
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The huge global demand for high-quality fish protein is increasing more quickly than it can be satisfied with existing supplies. To address this, fish protein concentrates (FPC) were created as one of the first attempts to recover protein from byproducts and underutilize fishery resources to use as a human meal. Fish protein concentrate (FPC) is a beneficial compound obtained from the remains of fish processing that provides a nutrient-rich solution to tackle worldwide food security issues. The protein content of FPC is remarkably high, ranging from 75% to 95%. This exceptional quality protein is obtained through solvent extraction from various fish species. As the population continues to increase and the need for protein-rich foods grows, FPC proves to be a sustainable and environmentally-friendly alternative that improves nutrition, reduces waste, and supports the fishing industry.
... Amino acids are the building blocks of proteins and are essential for various physiological processes, including immune function and neurotransmitter synthesis. Consuming fruits rich in amino acids supports overall health and mental well-being [68] . Amino acids are crucial for maintaining gut barrier function and supporting the repair and regeneration of intestinal epithelial cells. ...
... Some amino acids are classified as essential, as humans cannot synthesise them, and their source must be the diet. Amino acids play an important role in regulating gene expression, nutrient transport and metabolism, and anti-oxidative responses, among others [16,17]. Incorporating these food by-products into food products, such as bakery products, which are generally nutritionally poor, provides multifunctionality, reducing land use and promoting the circular economy [4,18]. ...
Article
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The use of fruit by-products to develop new food products could be an advantageous approach to meet the demand for healthy foods and reduce food waste. In this study, the amino acid and mineral profiles of melon peel flour were evaluated. Non-essential/toxic elements were also determined. Furthermore, two formulations (biscuit and muffin) were developed with 50% and 100% melon peel flour, respectively. The bioaccessibility of essential minerals in these two formulations was also determined. These innovative products presented interesting contents of amino acids and high levels of minerals, contributing significantly to daily mineral requirements, mainly magnesium (18–23%), phosphorus (13–28%), molybdenum (14–17%), and manganese (10–13%). Regarding the in vitro bioaccessibility of minerals in the developed formulations, magnesium, manganese, sodium, and phosphorus were those with the highest values (75–108%). Based on these results, melon peel has the potential to improve global food security, nutrition, economic well-being, and overall health and well-being.
... In addition to their role as nutrients and flavor precursors, amino acids are also classified as functional amino acids, which regulate key metabolic pathways to improve health, growth, and development in animals (Wu, 2013). These pathways include amino acid synthesis and Fig. 5. ...
Article
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The quality of lamb meat from natural pastures tends to be influenced by the pasture's condition. This study investigated the impact of grazing intensity on lamb meat quality, identifying moderate grazing as optimal for enhancing meat attributes such as higher a∗45min values, larger loin eye areas, reduced drip loss, and lower shear force. Proteins related to muscle structure (SLC4A1 and FMNL2) and metabolic enzymes (AKR1C1 isoform X1, PGFS, and Inmt) emerged as potential biomarkers for tenderness. Enriched differential metabolic pathways, particularly those associated with amino acid metabolism like tyrosine, arginine, and proline metabolism, were noted. Lambs under heavy grazing exhibited elevated levels of proline, which may lead to tougher lamb meat. Additionally, heavy grazing lambs showed increased levels of six key amino acids (arginine, glutamic acid, isoleucine, phenylalanine, proline, and tyrosine), the main mechanisms were activation of metabolic pathways, involving glycolytic enzyme (ALDOB) and gluconeogenic enzyme (FBP1) and few others metabolism enzymes (ADH1C, SULT1C4, ACAT2 and Aldh1l1). Oxidative stress and response to stress proteins (HP, CAT and RGN) were also participated in amino acid accumulation. The data reflected the vital role of metabolic enzymes in regulating lamb meat quality.
... Especially when carbohydrates and fats are not available, amino acids can be used to provide energy. Immune System: Some amino acids support the function of immune system cells and are involved in the body's defense mechanisms (32,33). ...
Conference Paper
Bee products are the subject of many scientific studies due to their natural and high biological activity. Bee products are primarily honey, followed by pollen, propolis, royal jelly, apilarnil, bee venom, and bee bread (perga). While honey is the most established bee product, today other bee products are also known for their rich bioactive chemicals and their extensive biological activities. Propolis and royal jelly contain more secondary metabolites and show more biological activity than other bee products. Amino acids are very significant as they form the building blocks of proteins. They play a critical role in protein synthesis, enzyme activities, cellular functions, and metabolism. In particular, the essential ones should be supplied from outside (such as lysine, methionine, tryptophan, and valine). Deficiencies cause many metabolic diseases and tissue damage. In this review, the amino acid contents of bee products, which are consumed as natural food and are a source of healing, and the relations of these amino acids with antioxidant properties were compiled with current studies. The definitions of bee products, their amino acid contents,and their connections with antioxidant activity were scanned in Web of Science, GoogleScholar, Scopus, Pubmed and Tr index and the data of current studies were collected andinterpreted. It has been determined by studies that different types of bee products have differentchemical contents. In addition, it has been determined in studies that some amino acids may beresponsible for antioxidant properties. With this review, the amino acid content of bee productshas been revealed with current studies.
... На долю лейцина, изолейцина и валина приходится 35% незаменимых аминокислот в структурных элементах мышц, но АРЦ выполняют и другие метаболические функции (Wu, 2013). Среди АРЦ лейцин занимает особое место в связи с его специфической функцией в активации сигнального пути mTOR. ...
Article
В последние годы выявлен ряд новых функций незаменимых аминокислот с алифатическими разветвлёнными цепями (АРЦ) при различных состояниях организма у животных и человека. Эти аминокислоты участвуют в регуляции метаболизма не только белков, но также липидов и углеводов, поддерживают здоровье молочных желез и кишечника, повышают качество молока и помогают в ранней имплантации и развитии эмбрионов. АРЦ (особенно лейцин) повышают синтез белков, и в настоящее время они рассматриваются как кормовые добавки для улучшения мясной продуктивности и качества мяса при выращивании и откорме свиней. Основные разделы обзора: метаболические функции лейцина, изолейцина и валина; метаболизм АРЦ; функции АРЦ как сигнальных молекул; значение АРЦ в питании животных. Новые аспекты метаболических и регуляторных функций АРЦ включают в себя ряд закономерностей: 1) недостаточный или чрезмерный уровень их в рационе усиливает липолиз; 2) эти аминокислоты, особенно изолейцин, играют важную роль в утилизации глюкозы за счет активации транспортёров глюкозы в кишечнике и мышцах; 3) эти аминокислоты усиливают развитие кишечника, транспорт аминокислот в кишечнике и производство муцина; 4) лейцин, изолейцин и валин участвуют в регуляции врождённых и адаптивных иммунных ответов. В ближайшей перспективе использование высокопроизводительной функциональной геномики, метаболомики и протеомики позволит в большей мере раскрыть функции АРЦ в экспрессии генов, синтезе белков и регуляции метаболизма. In recent years, a number of new functions of branched-chain amino acids (BCAA) - leucine, valine and isoleucine - have been revealed in various states of the body in animals and humans. These amino acids are involved in the regulation of the metabolism of not only proteins, but also lipids and carbohydrates, maintain the health of the mammary glands and intestines, improve milk quality and help in early implantation and development of embryos. BCAA (especially leucine) increase protein synthesis and are currently considered as feed additives to improve meat productivity and meat quality in raising and fattening pigs. The main sections of the review: metabolic functions of leucine, isoleucine and valine; metabolism of BCAA; functions of BCAA as signaling molecules; the importance of BCAA in animal nutrition. New aspects of metabolic and regulatory functions of BCCA include a number of regularities: 1) insufficient or excessive levels of them in the diet enhances lipolysis; 2) these amino acids, especially isoleucine, play an important role in glucose utilization by activating glucose transporters in the intestines and muscles; 3) these amino acids enhance the development of the intestine, the transport of amino acids in the intestine and the production of mucin; 4) leucine, isoleucine and valine are involved in the regulation of innate and adaptive immune responses. In the near future, the use of high-performance functional genomics, metabolomics, and proteomics will make it possible to more fully reveal the functions of BCCA in gene expression, protein synthesis, and metabolism regulation.
... Methionine (Met) happens to be the initiating amino acid for the protein synthesis in eukaryotic cells [4]. Met is necessary as a methyl donor for numerous methylation events, including DNA methylation, and as a precursor to polyamines, L-carnitine, and cysteine [5]. Met also serves as a signaling molecule for regulating immunity, energy metabolism, and reproduction [6]. ...
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The study aimed to evaluate the effect of dietary taurine and methionine ratios on growth performance, digestive enzyme activity, metabolic enzyme activity, antioxidant status and innate immune responses in pangasius fingerlings when fed with plant ingredients. Four isonitrogenous (300 g/kg crude protein) and isolipidic (60 g/kg crude lipid) diet with varying ratios of Tau (g/kg)/Met (g/kg) (T0/M25, T5/M20, T10/M15, and T15/M10) were prepared. Pangasius (Pangasianodon hypophthalmus) fingerlings were randomly stocked in twelve 150 L FRP tanks with 20 fingerlings (6.43 ± 0.06 g) in each and fed experimental diets for 60 days. Final weight, weight gain, specific growth rate and protein efficiency ratio were significantly higher (P < 0.001) in T15/M10 group and the same group showed lower feed conversion ratio. The whole-body crude protein and ash showed a positive linear and quadratic response (P < 0.001) and was highest in T15/M10 group. Likewise, the same group showed lowest crude lipid and moisture and exhibited negative linear and quadratic responses. Serum glucose and triglycerides were also significantly lower (P < 0.05) in T15/M10 group. The protease, amylase and lipase had a positive linear and quadratic response (P < 0.001) and were significantly higher (P < 0.05) in T15/M10 group. Metabolic enzymes viz. aspartate aminotransferase, alanine aminotransferase, glutamate dehydrogenase, glucose 6 phosphate dehydrogenase, hexokinase, and fructose 1,6 bisphosphate showed significantly higher (P < 0.05) activity in T15/M10 diet and except for glutamate dehydrogenase which has no apparent effect. The antioxidant enzyme activity such as superoxide dismutase, catalase, glutathione S-transferase and glutathione peroxide showed a positive linear and quadratic (P < 0.05) response to different Tau/Met ratio. Lipid peroxidation activity showed negative linear and quadratic responses (P < 0.001) and was significantly lower (P < 0.05) in T15/M10 group. Respiratory burst activity and lysozyme activity showed a positive linear and quadratic response (P < 0.001) and were significantly higher (P < 0.05) in T15/M10 group. The expression level of proinflammatory gene, Interleukin-1β did not show any significant difference among the treatments (P > 0.05). The transferrin gene expression was upregulated in T15/M10 group. In summary, the growth performance was increased when the taurine in the diet increased, whereas the only methionine diet ceased the growth performance. It seems that methionine is not as efficient as supplementing intact dietary taurine. The T15/M10 diet showed to be the best inclusion for pangasius in a plant-based diet.
... On the other hand, in the PCA loading plot (Figure 1), the weak relationships between some amino acids (phenylalanine, glycine, glutamic acid, alanine, arginine, serine, aspartic acid, and isoleucine) and oxygen percentage, salinity, temperature, and pH confirm the hypothesis that some amino acids are dependent on food availability rather than the abiotic parameters measured. Ultimately, these amino acids regulate key metabolic pathways, enhancing the health, survival, growth, development, lactation, and reproduction of the organisms, thereby increasing the nutritional value of O. edulis [37]. ...
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The quality aspects of Ostrea edulis (O. edulis) cultured in Valli di Comacchio were examined across different seasons. Nutritional quality parameters, antioxidant activity, total carotenoids, and contaminants were determined in winter, summer, and autumn (December, June, and October). Seasonal variations in nutritional parameters were observed. In particular, in the winter samples, proteins, eicosapentaenoic acid, docosahexaenoic acid, threonine, tyrosine, valine and methionine, isoleucine, potassium, and carotenoids showed the highest values, whereas oleic acid, linolenic acid, lysine, and magnesium exhibited the maximum values in the summer. Finally, lipids, carbohydrates, histidine, and magnesium were present at high values in the autumn. The antioxidant activity values differed between the two methods used (DPPH and photochemiluminescence assays); however, the oysters collected in June presented lower antioxidant capacity. Contaminant levels were always below the imposed concentration limits; however, higher levels of toxic metals were detected in the winter, while polycyclic aromatic hydrocarbons were detected in the summer and autumn. It is important to monitor the nutritional and toxicological quality of Ostrea edulis throughout the cultivation seasons, not only to enhance knowledge of this species and improve its cultivation systems but also to determine the optimal period for human consumption from both nutritional and toxicological perspectives.
... This may be particularly pertinent since BCAAs are essential amino acids and can only be, in humans, derived from the diet. BCAAs are also key for stimulating protein biosynthesis and tissue development [75][76][77][78] . Moreover, growth-restricted compared to AGA fetuses have lower plasma concentrations of BCAAs in the umbilical artery and vein 79 . ...
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The pathways involved in the pathophysiology of fetal growth restriction (FGR) and small for gestational age (SGA) are incompletely understood. We conduct a systematic review to identify metabolomic signatures in maternal and newborn tissues and body fluids samples associated with FGR/SGA. Here, we report that 825 non-duplicated metabolites were significantly altered across the 48 included studies using 10 different human biological samples, of which only 56 (17 amino acids, 12 acylcarnitines, 11 glycerophosphocholines, six fatty acids, two hydroxy acids, and eight other metabolites) were significantly and consistently up- or down-regulated in more than one study. Three amino acid metabolism-related pathways and one related with lipid metabolism are significantly associated with FGR and/or SGA: biosynthesis of unsaturated fatty acids in umbilical cord blood, and phenylalanine, tyrosine and tryptophan biosynthesis, valine, leucine and isoleucine biosynthesis, and phenylalanine metabolism in newborn dried blood spot. Significantly enriched metabolic pathways were not identified in the remaining biological samples. Whether these metabolites are in the causal pathways or are biomarkers of fetal nutritional deficiency needs to be explored in large, well-phenotyped cohorts.
... Glutamine is one of the most abundant free AAs in the human body, and it can replace glucose in the TCA cycle under hypoxic conditions. It also exerts an important effect on various physiological processes, including the synthesis of DNA, RNA, proteins, aminosaccharides, and glucose [114]. ...
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Metabolic reprogramming is a pivotal biological process in which cellular metabolic patterns change to meet the energy demands of increased cell growth and proliferation. In this review, we explore metabolic reprogramming and its impact on fibrotic diseases, providing a detailed overview of the key processes involved in the metabolic reprogramming of renal fibrosis, including fatty acid decomposition and synthesis, glycolysis, and amino acid catabolism. In addition, we report that Chinese medicine ameliorates renal inflammation, oxidative stress, and apoptosis in chronic kidney disease by regulating metabolic processes, thereby inhibiting renal fibrosis. Furthermore, we reveal that multiple targets and signaling pathways contribute to the metabolic regulatory effects of Chinese medicine. In summary, this review aims to elucidate the mechanisms by which Chinese medicine inhibits renal fibrosis through the remodeling of renal cell metabolic processes, with the goal of discovering new therapeutic drugs for treating renal fibrosis.
... 7 Functional AAs show immense potential in preventing and treating infectious diseases (including viral infections), metabolic disorders (such as obesity, diabetes, and cardiovascular diseases), lactation failure, fetal and postpartum growth restriction, male and female infertility, and organ dysfunctions. 8 Therefore, a qualitative and quantitative assessment of AAs in body uids is crucial, and it is important to use a sensitive and reliable system to ensure accurate results. ...
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An ultra-sensitive, high-performance liquid chromatography-based laser-stimulated fluorescence detection system was developed and validated for the simultaneous detection of 20 derivatized amino acids. Dansyl chloride was used as a derivatizing agent, and key derivatization parameters, such as reaction time and temperature, were optimized to enhance sensitivity and reproducibility. The majority of amino acids showed a relative standard deviation of less than 5%, indicating the reliability of the approach. The method demonstrated excellent sensitivity for all 20 amino acids, with detection limits ranging from 4.32 to 85.34 femtomoles. It also exhibited good linearity, with regression (R²) values greater than 0.98 for the amino acids. The system's performance was tested on human serum, and the eluted amino acids were identified. This method has great potential for analyzing amino acids in various body fluids and can be used in various clinical applications. It is ultra-sensitive, reliable, user-friendly, and cost-effective, offering a valuable tool for diagnosing and managing amino acid-related disorders.
... Twenty amino acids are required for healthy animal function, especially fish and are classed as essential or non-essential based on their ability to be produced. Fish nutrition studies have also shown that several amino acids are regarded as functional amino acids (FAA), such as leucine, arginine, methionine, proline, cystine, glutamine, glutamate taurine, tyrosine, tryptophan and aspartic acids, are associated with and regulated by significant metabolic pathways that are connected to fish health, growth, development, reproduction, antioxidant defense and survival (Wu, 2013). Studies have shown that adding functional amino acids to aquafeed improved the overall performance of a variety of aquatic species and that reducing FAA in aquafeed stunted fish development and health, particularly when the fish were fed a diet heavy in plant ingredients (Hossain et al., 2024). ...
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Fishmeal is a very important protein source in fish feed, but its limited availability compared to the growing demand forces fish nutritionists to explore other protein sources. However, increasing the amount of alternative proteins in fish feed to a certain limit can sometimes decrease fish performance. To mitigate the adverse impacts of including plant proteins in aquafeed, the researchers are investigating various approaches, such as altering the processing of feed ingredients, feed formulation, and feed supplementation. Supplementation with functional feed additives (FuFAs) including organic acids, nucleotides, prebiotics, probiotics and particular amino acids, have shown promise in improving the effectiveness of incorporating alternative protein, enhancing fish growth and health. Nonetheless, there are still many unknown things about how FuFAs affect digestion, absorption, species variations, age-related responses, metabolism and physiological responses in fish fed with alternative protein-based feed. To enhance fish performance, it is necessary to use biochemical and molecular technologies to better comprehend the function of FuFAs in fish feed. Additionally, actions are required to develop cost-effective production technologies for functional feed supplements. Furthermore, further research is necessary to explore the potential of functional feeds in disease prevention and reducing dependence on chemical interventions and antibiotics in aquaculture, thus promoting environmentally sustainable practices.
... Essential amino acids must be obtained from the diet, while nonessential amino acids can be synthesized by the body. Recent research has shown that some nonessential amino acids, such as glycine and cysteine, are crucial in regulating metabolic and signaling pathways, nutrient metabolism and intracellular protein turnover [48,49]. Previous study on tilapia indicated no statistically difference among amino acid profile of tilapia [41] and grass carp [42]. ...
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The study investigated the impact of N-acetyl cysteine on growth, immune response, and antioxidant activity in tilapia (Oreochromis niloticus). Fish were reared at three densities (1.50, 3.00, and 4.50 kg/m³) with four levels of N-acetyl cysteine supplementation (0, 2, 4, and 6 mg/kg) over 60 days. Better growth was observed at low density, but at all densities, fish fed the highest N-acetyl cysteine level (6 mg/kg) showed improved growth. Chemical composition of fish and activity of amylase, lipase and protease in all treatments were noted to be insignificant. The levels of antioxidant enzymes (catalase, superoxide dismutase and glutathione peroxidase) and cortisol in HD treatments were high as compared to LD and MD treatment. However, fish fed with N3 diet in each density treatment showed the lowest level of antioxidant enzymes as well as cortisol. Similarly, the levels of malondialdehyde were noted to be high at HD treatments as compared to that in LD and MD. Its levels were lower in fish fed with N3 diets in all density treatments. Expression of somatostatins-1 did not increase in MD and HD treatments in response to high stocking density when compared with LD treatment. However, pro-opiomelanocortin-α level was reduced after N3 diet in HD treatment and interleukin 1-β expression increased after N3 supplement in HD treatment. In conclusion, N-acetyl cysteine supplementation improved growth and antioxidant response in tilapia. The most optimum dose of N-acetyl cysteine was noted to be 6 mg/kg at high stocking, suggesting the potential role of this nutraceutical in tilapia intensive culture.
... NO is a classic vasodilator factor. Both vascular endothelial cells and smooth muscle cells can use Larginine as a precursor to generate NO under the action of nitric oxide synthase (NOS) [21]. NO acts as a small gas molecule, which can increase the content of cyclic guanylate (cGMP) by diffusing free guanylate cyclase (sGC) in vascular smooth muscle cells, thereby activating cGMP-dependent protein kinase (PKG) by acting on the cell membrane, reducing the in ux of extracellular calcium ions; acting on the endoplasmic reticulum, reducing the calcium content in the calcium pool; activating the activity of myosin light chain phosphatase (MLCP) and inhibiting the dephosphorylation of myosin light chain. ...
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Purpose Neurohormone-regulated peripheral vascular resistance is considered one of the factors governing blood pressure. This study was designed to evaluate the effect of arginine vasopressin (AVP) on contraction of endothelium-intact or -denuded rat aorta and mesenteric resistant arteries. Methods The wire myograph technique was used to assess the contractility of the vascular smooth muscles in response to a high-K⁺, phenylephrine, AVP, and inhibitors, etc. The time-course of agonist-evoked contraction was then recorded. The endothelium of the mesenteric resistance arteries and abdominal aorta were denuded by physical abrasion, as evidenced by acetylcholine-induced vasodilation dysfunction. Results Our result revealed that (1) AVP, but neither high K⁺ nor phenylephrine, evoked transient contraction of abdominal aorta and mesenteric resistance arteries; (2) Endothelial removal, V2 receptor antagonists, sGC inhibitors, or nitric oxide(NO) synthase inhibitors reversed the transient contraction of mesenteric resistance arteries into sustained contraction, but not in aorta;(3) Pharmacological inhibition of GRK2 altered AVP-elicited temporal contractile response into a sustained contraction in denuded aortic endothelium;(4) The vasopressin receptor V1A blocker abolished AVP-induced contractile responses in both vessel preparations. Conclusion V2-mediated NO pathway in endothelium and the V1A-mediated GRK2 signaling pathways in smooth muscle are involved in AVP-induced transient contractions in rat mesenteric resistance and aortic vessels, respectively.
... disciplines utilize the traditional AA classification, novel and innovative strategies have been implemented to better characterize the need for AAs in the diets of farmed fish based on a wholistic approach to AA nutrition. Wu (2013) coined the "functional" AA philosophy, pioneering a new approach to AA supplementation in the diets of fish and other farmed animals based on overall benefits to metabolic and physiological processes and not exclusively growth. Under the functional AA concept, AAs classically deemed nonessential could impart beneficial effects when supplemented to diets (e.g., high-plant-protein diets). ...
... Additionally, the elevated levels of essential amino acids, such as leucine, are associated with an increased rate of collagen degradation (Zhai, 2019). Further, amino acids regulate metabolic pathways associated with health, survival, growth, development, and reproduction, with some related to chronic pain (Wu, 2013). ...
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Introduction Obesity aligned with quadriceps muscle weakness contributes to the high incidence of knee osteoarthritis (KOA), which is prevalent in women. Although molecular signatures of KOA have been suggested, the association between biopsychosocial responses and the plasma metabolomic profile in overweight/ obese women with KOA remains in its early stages of investigation. This study aims to associate the plasma metabolome with biopsychosocial parameters of overweight/obese women diagnosed with KOA. Methods Twenty-eight overweight/obese women (Control-n = 14; KOA-n = 14) underwent two visits to the laboratory. Functional tests and questionnaires assessing biopsychosocial parameters were administered during the first visit. After 48 h, the participants returned to the laboratory for blood collection. Specific to the KOA condition, the Numerical Pain Rating Scale (NPRS), Tampa Scale for Kinesiophobia (TSK), and Knee injury and Osteoarthritis Outcome Score (KOOS) were applied Results Thirteen molecules were different between groups, and four correlated with KOA’s biopsychosocial parameters. DG 22:4-2OH and gamma-Glutamylvaline were inversely associated with KOSS leisure and TSK score, respectively. LysoPE 18:0 and LysoPE 20:5 were positively associated with KOSS symptoms and TSK score, respectively. Discussion While the correlations of LysoPE 18:0 and gamma-Glutamylvaline are supported by existing literature, this is not the case for DG 22:4-2OH and LysoPE 20:5. Further studies are recommended to better elucidate these correlations before dismissing their potential involvement in the biopsychosocial factors of the disease.
... Disruptions in amino acid levels impact protein synthesis, immune function, and energy processes (Wu, 2010(Wu, , 2013, exacerbating wasting and cachexia in HIV and TB patients (Luies & Du Preez, 2020). Lower amino acid levels in HIV may activate enzymes that inhibit RNA virus replication, potentially affecting HIV severity (Afroz et al., 2020;Del Pino et al., 2012). ...
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Introduction The human immunodeficiency virus (HIV) and tuberculosis (TB) co-infection presents significant challenges due to the complex interplay between these diseases, leading to exacerbated metabolic disturbances. Understanding these metabolic profiles is crucial for improving diagnostic and therapeutic approaches. Objective This study aimed to characterise the urinary acylcarnitine and amino acid profiles, including 5-hydroxyindoleacetic acid (5-HIAA), in patients co-infected with HIV and TB using targeted liquid chromatography mass spectrometry (LC–MS) metabolomics. Methods Urine samples, categorised into HIV, TB, HIV/TB co-infected, and healthy controls, were analysed using HPLC–MS/MS. Statistical analyses included one-way ANOVA and a Kruskal-Wallis test to determine significant differences in the acylcarnitine and amino acid profiles between groups. Results The study revealed significant metabolic alterations, especially in TB and co-infected groups. Elevated levels of medium-chain acylcarnitines indicated increased fatty acid oxidation, commonly associated with cachexia in TB. Altered amino acid profiles suggested disruptions in protein and glucose metabolism, indicating a shift towards diabetes-like metabolic states. Notably, TB was identified as a primary driver of these changes, affecting protein turnover, and impacting energy metabolism in co-infected patients. Conclusion The metabolic profiling of HIV/TB co-infection highlights the profound impact of TB on metabolic pathways, which may exacerbate the clinical complexities of co-infection. Understanding these metabolic disruptions can guide the development of targeted treatments and improve management strategies, ultimately enhancing the clinical outcomes for these patients. Further research is required to validate these findings and explore their implications in larger, diverse populations.
... In contrast, glutamine, glycine, glutamic acid, proline, and taurine are the CEAAs, and aspartic acid, alanine, and serine are the NEAAs for humans [9]. However, the functional amino acids (FAAs) have been proposed in recent years, and the participation of FAAs is considered for regulating the key metabolic pathways concerning the improvement of health, survival, development, growth, lactation, and reproduction, as well as the prevention of diseases [3,25]. AAs are also classified according to the taste rendered by them, like the sweet taste AAs (serine, alanine, and glycine), and the umami taste AAs (aspartic acid and glutamic acid) [26]. ...
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Amino acids are significant biomolecules that govern the major metabolic processes and act as precursors for macromolecules such as proteins that are crucial to life. Fish is an integral component of human nutrition and a dietary source of high-quality animal proteins and amino acids. In this context, the crude protein and amino acid compositions of food fish from different landing stations of the Ganga river have been determined. The Kjeldahl method was utilized to determine the crude protein content and the amino acids were analyzed using high-performance liquid chromatography (HPLC); data on 30 food fish were assessed. The study showed that among the fish studied, Eleotris fusca, Macrobrachium malcomsonii, and Mystus cavasius were rich in most of the amino acids important for human nutrition, such as glycine, glutamic acid, cysteine, threonine, phenylalanine, methionine, lysine, leucine, isoleucine, histidine, and valine. Further, it was observed that the daily consumption of these fish (approximately 50 g) can fulfil the daily requirement of these individual amino acids for an adult human with a body weight of 60 kg. Therefore, the amino acid composition analyzed in the present study could be utilized for recommendation by clinicians according to the requirement for specific amino acids, and fish can be prescribed as a natural supplement against the amino acid requirement.
... Glutamic acid plays an essential role in transamination reactions for the synthesis of key molecules, such as glutathione, which is required to remove highly toxic peroxides and polyglutamate folate cofactors (Mohanty et al., 2014). According to Zhong et al. (2003) and Wu (2013), functional amino acids, such as glycine, have the potential to reduce the production of major proinflammatory cytokines, thus limiting the accumulation of proinflammatory macrophages at injury sites. ...
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Aquaculture is a rapidly growing food production sector that aims to alleviate global hunger, malnutrition, food security and nutrient deprivation. This study aimed to update the full spectrum of nutritional composition using aquaculture species. High commodity value aquaculture species in Penang, Malaysia have been shortlisted, followed by nutritional quantification and health risk estimation. Nutritional compositional analysis involved proximate analysis, and amino acid, fatty acid, vitamin, mineral and heavy metal quantification. Health risk assessment was conducted to determine whether the benefits were greater than the risks in the long term. Ten (10) aquaculture species, namely golden pomfret, golden snapper, seabass, bigeye trevally, red snapper, grouper, African catfish, blood cockles, white-leg shrimp and tiger prawn, have been studied extensively. The results showed that all species contained adequate protein and lipid contents, ranging from 13.6 % to 26.9 % and 0.4-15.8 %, respectively. The essential amino acid (EAA) to total amino acid (TAA) ratio of the culture species was comparable to the FAO reference values (50 %), with leucine and lysine demonstrating the most important EAAs. Fatty acid profiling revealed that both seabass and grouper were rich in polyunsaturated fatty acids, particularly docosahexaenoic acid. Golden pomfret and red snapper contained the greatest amounts of riboflavin and pyridoxine. The atherogenic and thrombogenic indices were within the permissible ratio (<1), except for those of African catfish. Notably, the arsenic (As) content in blood cockles exceeded the permissible criterion values. Hazard index (HI) assessment indicated that prolonged consumption of blood cockles, white-leg shrimp, tiger prawn, bigeye trevally and golden snapper demonstrated potent non-carcinogenic risk for both adults and children. This study provides an initial platform for informing consumers, stakeholders and policy makers about aquaculture nutritional benefits, consumption safety concern and health indicators.
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This narrative review provides an analysis of the role of nitric oxide (NO) and its precursors, particularly L-arginine, in vascular regulation and health, with an emphasis on findings from our experimental research in animal models. NO serves as a critical mediator of vascular function, contributing to vasodilation, the regulation of blood flow, and the prevention of thrombosis. As a primary precursor of NO, L-arginine is essential for maintaining endothelial integrity, modulating mitochondrial function, and reducing oxidative damage. This review synthesises the data and contextualises these findings within the physiological challenges faced by blood donors, such as repeated blood donation and associated oxidative stress. It examines the effects of L-arginine supplementation on mitochondrial respiration, lipid peroxidation, and microsomal oxidation in different conditions, including differences in age, gender, and dietary interventions. The mechanisms by which L-arginine enhances NO production, improves vascular elasticity, and alleviates endothelial dysfunction caused by reduced NO bioavailability are also investigated. By integrating experimental findings with insights from the existing literature, this review provides a perspective on the potential of L-arginine supplementation to address the specific physiological needs of blood donors. It highlights the importance of personalised nutritional approaches in enhancing donor recovery and vascular resilience. In addition, this review assesses the wider implications of L-arginine supplementation in mitigating oxidative stress and preserving vascular function. The interplay between NO bioavailability, dietary factors, and physiological adaptation in blood donors is highlighted, along with the identification of current knowledge gaps and recommendations for future research. By presenting both original experimental evidence and a critical synthesis of the literature, this article highlights the therapeutic potential of NO precursors, particularly L-arginine, in promoting vascular health in the context of blood donation.
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Background: Grapes are one of the most important agricultural products in Malayer, and the pest Psalmocharias alhageos affects them. Imidacloprid, a systemic neonicotinoid insecticide, is commonly used to control pests. This study aims to assess the effectiveness of non-toxic household methods in reducing imidacloprid residues on grapes. Methods: The grape samples were collected from five different vineyards and immersed in various solutions (acetic acid, sodium bicarbonate, sodium chloride, detergents, and tap water). The QuEChERS method was used for pesticide residue extraction. Results: Washing treatments significantly reduced pesticide residues in the grapes. The reduction in imidacloprid residues varied, with sodium bicarbonate showing the highest reduction (50.41%), followed by acetic acid (30.03%), detergent (9.44%), sodium chloride (8.81%), and tap water (3.45%). The processing factors (PFs) after washing with these solutions were all less than 1, indicating that all treatments were effective in reducing imidacloprid residues. Conclusion: Imidacloprid residues were detected in all grape samples from the five vineyards. However, the imidacloprid concentrations after washing were below the CODEX maximum residue limit (MRL) (0.7 mg/kg). Health risk assessments indicated that consumers are not exposed to significant health risks from imidacloprid residues in grapes, with no serious side effects observed for adults, adolescents, or children.
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The metabolomic approach has recently been used in the assessment of semen quality and male fertility. Additionally, the crucial roles of branched-chain amino acids (BCAAs) and aromatic amino acids (AAAs) in metabolic syndrome (MetS) were reported. However, little information exists about the association between BCAAs and AAAs with semen parameters, particularly in men with and without MetS. Our objective was to explore the association between BCAAs and AAAs in blood and seminal plasma and sperm parameters in men with MetS (MetS +) and without MetS (MetS-). In a cross-sectional study between January-July 2022, we investigated 98 men (age: 25–42 years; MetS + : n = 28 and MetS-: n = 70) at Royan Institute, Tehran, Iran. All participants underwent anthropometric indices measurements using standard protocols. From each participant, a single fasting blood sample was collected on the same day that the semen sample was collected. The BCAAs and AAAs in blood and seminal plasma were measured using high-performance liquid chromatography (HPLC). The aromatase activity (total testosterone/ estradiol ratio) was significantly lower in MetS + (0.16) than MetS- (0.35) (p = 0.016). Semen parameters were similar between the MetS + and the MetS- groups. All BCAA and AAA family members, except tryptophan, were higher in the blood plasma of men with metabolic syndrome. Meanwhile, the seminal plasma of BCAA and AAAs were similar. Intriguingly, Valine in blood (r = -0.329; p < 0.001) and seminal (r = -0.237; p < 0.05) plasma were correlated with abnormal sperm morphology in patients without metabolic syndrome (MetS-). Further research is necessary to validate these findings and to explore the underlying mechanisms and interactions between the plasma BCAAs and AAAs and sperm parameters.
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The transition toward plant-based (PB) diets has gained attention as a plausible step toward achieving sustainable and healthy dietary goals. However, the complete elimination of all animal-sourced foods from the diet (ie, a vegan diet) may have nutritional ramifications that warrant close examination. Two such concerns are the adequacy and bioavailability of amino acids (AAs) from plant-sourced foods and the consequences for older vegan populations who have elevated AA requirements. This narrative review describes the challenges of achieving high protein quality from vegan diets. Data were synthesized from peer-reviewed research articles and reviews. Plant-sourced proteins provide poorer distribution of indispensable AAs (IAAs) and have poorer digestibility, partly due to their inherent structural components within the food matrix. The review addresses complexities of combinations of varied plant protein sources and why the inclusion of novel PB alternatives adds uncertainty to the achievement of adequate protein adequacy. Meal distribution patterns of protein and the ensuing physiological impacts deserve further research and are outlined in this review. Particular attention is given to describing the challenges of achieving sufficient protein and IAA intakes by aging populations who choose to follow a vegan diet. This review contributes to the emerging discussions of nutritional risks associated with vegan diets and adds perspective to the current dietary shifts toward PB diets.
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The nitrogen‐free diet (NFD) method for determining basal ileal endogenous losses (BEL) of amino acids (AA) has been associated with different metabolic abnormalities that can affect the accurate determination of BEL. Consequently, the use of highly digestible proteins has been suggested. This study aimed to determine the metabolic status and BEL of AA in pigs fed either an NFD or a casein (CAS) diet. Eight cannulated, castrated male pigs (39.8 kg) were randomly assigned to a 2 × 2 crossover design. An NFD diet based on corn starch, dextrose, cellulose, oil, vitamins and minerals was used. The CAS diet was equivalent, but 18% of the corn starch was replaced with casein. Pigs were fed one of the diets for a 7‐day period, and blood samples were collected at the beginning and end of each period to determine plasma metabolites. Ileal digesta samples were collected on Days 6 and 7 to estimate the BEL of the AA. Results indicated that plasma albumin was significantly higher ( p < 0.05) in pigs fed the CAS diet, whereas creatinine and LDL levels were higher ( p < 0.03) in pigs fed the NFD. No significant differences were observed in the levels of other plasma metabolites. The BEL of protein did not differ between diets. However, in pigs fed the CAS diet, the BEL of glutamic acid, aspartic acid, serine, glycine, histidine, threonine, alanine, tyrosine and valine significantly increased ( p < 0.05), while isoleucine showed a tendency to increase ( p = 0.06). In conclusion, NFD did not significantly affect energy and lipid metabolism in pigs. However, the decrease in albumin synthesis and increase in plasma creatinine levels indicate that pigs fed NFD have a negative protein balance, affecting the estimation of the BEL of AA. Therefore, it is essential to consider the metabolic state of animals when estimating the BEL of AA.
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Amino acid transporters (AATs) are described as pivotal in maintaining circulating and cellular concentrations of AA via regulation of their expression in response to the cellular environment. Rainbow trout (RT), a complex genome species, is poorly described for AATs roles in controlling its predominant AA-based metabolism, despite representing a major challenge in the aquaculture nutrition field. Therefore, we identified the whole repertoire of AAT found in RT genome (>200), its expression in tissues and its nutritional regulations in vitro. Results garnered revealed the existence of different clusters of AATs, notably due to promoters bearing ATF4-related AA response elements. Moreover, the modeling of each AAT-specific cluster activities disclosed mTOR-related signaling functions of Ile and Phe, yet unknown in RT. Thus, this novel approach herein described should help to better grasp AA homeostasis in most organisms and topics such as fish nutrition and evolution.
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Village chickens (Gallus gallus domesticus) are commonly reared in rural households of South Africa and other developing countries. They play a vital role as a primary source of protein through the provision of meat and eggs. The chicken gut microbiota plays an important role in chicken’s immune system, its health, physiological development of the gut, digestion of food, nutrient absorption and productivity. Thus, it is imperative to critically investigate the chicken microbial composition in order to develop effective disease control measures and increase production. In this present study, microbial DNA was isolated from 34 non-descript mixed gender matured village chickens’ intestinal contents followed by high throughput Illumina sequencing targeting 16S rRNA gene. Senwamokgope village had the largest microbiota composition as compared to Itieleni and Thakgalang villages. Overall, Firmicutes (74%) was the most abundant phylum observed, followed by Proteobacteria (8%), Actinobateria (5%), and Bacteroidota (3%). At the genus level, Lactobacillus was the dominant bacteria. Other genera found included Sphingomonas (7%), Cutibacterium (4%), and Clostridium_sensu_stricto_1 (2%). The richness of female intestinal microbiota was higher compared to the male microbiota. The findings of this study provide baseline information that can assist to better understand the chicken gut microbiota and its interaction with diseases and parasites.
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Glycine is a major amino acid in mammals and other animals. It is synthesized from serine, threonine, choline, and hydroxyproline via inter-organ metabolism involving primarily the liver and kidneys. Under normal feeding conditions, glycine is not adequately synthesized in birds or in other animals, particularly in a diseased state. Glycine degradation occurs through three pathways: the glycine cleavage system (GCS), serine hydroxymethyltransferase, and conversion to glyoxylate by peroxisomal D-amino acid oxidase. Among these pathways, GCS is the major enzyme to initiate glycine degradation to form ammonia and CO2 in animals. In addition, glycine is utilized for the biosynthesis of glutathione, heme, creatine, nucleic acids, and uric acid. Furthermore, glycine is a significant component of bile acids secreted into the lumen of the small intestine that is necessary for the digestion of dietary fat and the absorption of long-chain fatty acids. Glycine plays an important role in metabolic regulation, anti-oxidative reactions, and neurological function. Thus, this nutrient has been used to: (1) prevent tissue injury; (2) enhance anti-oxidative capacity; (3) promote protein synthesis and wound healing; (4) improve immunity; and (5) treat metabolic disorders in obesity, diabetes, cardiovascular disease, ischemia-reperfusion injuries, cancers, and various inflammatory diseases. These multiple beneficial effects of glycine, coupled with its insufficient de novo synthesis, support the notion that it is a conditionally essential and also a functional amino acid for mammals (including pigs and humans).
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Nitric oxide (NO) is a signaling molecule synthesized from L-arginine by NO synthase in animals. Increasing evidence shows that NO regulates the mammalian metabolism of energy substrates and that these effects of NO critically depend on its concentrations at the reaction site and the period of exposure. High concentrations of NO (in the micromolar range) irreversibly inhibit complexes I, II, III, IV, and V in the mitochondrial respiratory chain, whereas physiological levels of NO (in the nanomolar range) reversibly reduce cytochomrome oxidase. Thus, NO reduces oxygen consumption by isolated mitochondria to various extents. In intact cells, through cGMP and AMP-activated protein kinase signaling, physiological levels of NO acutely stimulate uptake and oxidation of glucose and fatty acids by skeletal muscle, heart, liver, and adipose tissue, while inhibiting the synthesis of glucose, glycogen and fat in the insulin-sensitive tissues, and enhancing lipolysis in white adipocytes. Chronic effects of physiological levels of NO in vivo include stimulation of angiogenesis, blood flow, mitochondrial biogenesis, and brown adipocyte development. Modulation of NO-mediated pathways through dietary supplementation with L-arginine or its precursor L-citrulline may provide an effective, practical strategy to prevent and treat metabolic syndrome, including obesity, diabetes, and dyslipidemia in mammals, including humans. © 2013 BioFactors, 2013.
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Protein is quantitatively the most expensive nutrient in swine diets. Hence it is imperative to understand the physiological roles played by amino acids in growth, development, lactation, reproduction, and health of pigs to improve their protein nutrition and reduce the costs of pork production. Due to incomplete knowledge of amino acid biochemistry and nutrition, it was traditionally assumed that neonatal, post-weaning, growing-finishing, and gestating pigs could synthesize sufficient amounts of all "nutritionally nonessential amino acids" (NEAA) to support maximum production performance. Therefore, over the past 50 years, much emphasis has been placed on dietary requirements of nutritionally essential amino acids as building blocks for tissue proteins. However, a large body of literature shows that NEAA, particularly glutamine, glutamate, arginine and proline regulate physiological functions via cell signaling pathways, such as mammalian target of rapamycin, AMP-activated protein kinase, extracellular signal-related kinase, Jun kinase, mitogen-activated protein kinase, and NEAA-derived gaseous molecules (e.g., nitric oxide, carbon monoxide, and hydrogen sulfide). Available evidence shows that under current feeding programs, only 70% and 55% of dietary amino acids are deposited as tissue proteins in 14-day-old sow-reared piglets and in 30-day-old pigs weaned at 21 days of age, respectively. Therefore, there is an urgent need to understand the roles and dietary requirements of NEAA in swine nutrition. This review highlights the basic biochemistry and physiology of absorption and utilization of amino acids in young pigs to enhance the efficacy of utilization of dietary protein and to minimize excretion of nitrogenous wastes from the body.
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Amino acids are necessary for the survival, growth, development, reproduction and health of all organisms. They were traditionally classified as nutritionally essential or non-essential for mammals, birds and fish based on nitrogen balance or growth. It was assumed that all "non-essential amino acids (NEAA)" were synthesized sufficiently in the body to meet the needs for maximal growth and health. However, there has been no compelling experimental evidence to support this assumption over the past century. NEAA (e.g., glutamine, glutamate, proline, glycine and arginine) play important roles in regulating gene expression, cell signaling, antioxidative responses, neurotransmission, and immunity. Additionally, glutamate, glutamine and aspartate are major metabolic fuels for the small intestine to maintain its digestive function and protect its mucosal integrity. Therefore, based on new research findings, NEAA should be taken into consideration in revising the classical "ideal protein" concept and formulating balanced diets to improve protein accretion, food efficiency, and health in animals and humans.
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Aging is associated with a gradual decline in skeletal muscle mass and strength leading to increased risk for functional impairments. Although basal rates of protein synthesis and degradation are largely unaffected with age, the sensitivity of older muscle cells to the anabolic actions of essential amino acids appears to decline. The major pathway through which essential amino acids induce anabolic responses involves the mammalian target of rapamycin (mTOR) Complex 1, a signaling pathway that is especially sensitive to regulation by the branched chain amino acid leucine. Recent evidence suggests that muscle of older individuals require increasing concentrations of leucine to maintain robust anabolic responses through the mTOR pathway. While the exact mechanisms for the age-related alterations in nutritional signaling through the mTOR pathway remain elusive, there is increasing evidence that decreased sensitivity to insulin action, reductions in endothelial function, and increased oxidative stress may be underlying factors in this decrease in anabolic sensitivity. Ensuring adequate nutrition, including sources of high quality protein, and promoting regular physical activity will remain among the frontline defenses against the onset of sarcopenia in older individuals.
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Branched-chain amino acids (BCAA) are actively taken up and catabolized by the mammary gland during lactation for syntheses of glutamate, glutamine and aspartate. Available evidence shows that the onset of lactation is associated with increases in circulating levels of cortisol, prolactin and glucagon, but decreases in insulin and growth hormone. This study determined the effects of physiological concentrations of these hormones on the catabolism of leucine (a representative BCAA) in bovine mammary epithelial cells. Cells were incubated at 37 °C for 2 h in Krebs buffer containing 3 mM D: -glucose, 0.5 mM L: -leucine, L: -[1-(14)C]leucine or L: -[U-(14)C]leucine, and 0-50 μU/mL insulin, 0-20 ng/mL growth hormone 0-200 ng/mL prolactin, 0-150 nM cortisol or 0-300 pg/mL glucagon. Increasing extracellular concentrations of insulin did not affect leucine transamination or oxidative decarboxylation, but decreased the rate of oxidation of leucine carbons 2-6. Elevated levels of growth hormone dose dependently inhibited leucine catabolism, α-ketoisocaproate (KIC) production and the syntheses of glutamate plus glutamine. In contrast, cortisol and glucagon increased leucine transamination, leucine oxidative decarboxylation, KIC production, the oxidation of leucine 2-6 carbons and the syntheses of glutamate plus glutamine. Prolactin did not affect leucine catabolism in the cells. The changes in leucine degradation were consistent with alterations in abundances of BCAA transaminase and phosphorylated levels of branched-chain α-ketoacid dehydrogenase. Reductions in insulin and growth hormone but increases in cortisol and glucagon with lactation act in concert to stimulate BCAA catabolism for glutamate and glutamine syntheses. These coordinated changes in hormones may facilitate milk production in lactating mammals.
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Glutamate is one of the most abundant of the amino acids. In addition to its role in protein structure, it plays critical roles in nutrition, metabolism and signaling. Post-translational carboxylation of glutamyl residues increases their affinity for calcium and plays a major role in hemostasis. Glutamate is of fundamental importance to amino acid metabolism, yet the great bulk of dietary glutamate is catabolyzed within the intestine. It is necessary for the synthesis of key molecules, such as glutathione and the polyglutamated folate cofactors. It plays a major role in signaling. Within the central nervous system, glutamate is the major excitatory neurotransmitter and its product, GABA, the major inhibitory neurotransmitter. Glutamate interaction with specific taste cells in the tongue is a major component of umami taste. The finding of glutamate receptors throughout the gastrointestinal tract has opened up a new vista in glutamate function. Glutamate is truly a functional amino acid.
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We proposed that the combination of conjugated linoleic acid (CLA) and arginine would decrease adiposity by depressing lipid synthesis in liver and adipose tissues of growing pigs. Pigs were allotted to treatments in a 2 × 2 factorial design with two lipids (CLA or canola oil) and two amino acids [L-arginine or L-alanine (isonitrogenous control)]; supplements were provided from 80 to 110 kg body weight (approximately 4 weeks). Treatment groups (n = 4) were: control (2.05% L-alanine plus 1% canola oil); CLA (2.05% L-alanine plus 1% CLA); arginine (1.0% L-arginine plus 1.0% canola oil); arginine plus CLA (1.0% arginine plus 1.0% CLA). Arginine increased backfat thickness (P = 0.07) in the absence or presence of CLA, and arginine supplementation increased subcutaneous and retroperitoneal adipocyte volume, especially in combination with dietary CLA (interaction P = 0.001). Arginine increased palmitate incorporation into total lipids by over 60% in liver (P = 0.07). Dietary CLA increased palmitate incorporation into lipids in longissimus muscle by over 100% (P = 0.01), and CLA increased longissimus muscle lipid by nearly 20%. CLA increased glucose oxidation to CO(2) by over 80% in retroperitoneal and subcutaneous adipose tissues (P = 0.04), and doubled palmitate oxidation to CO(2) in intestinal duodenal mucosal cells (P = 0.07). Arginine supplementation decreased muscle pH at 45 min postmortem (P = 0.001), indicating elevated early postmortem glycolysis, and CLA and arginine independently increased PGC-1α gene expression in longissimus muscle. CLA but not arginine depressed mTOR gene expression in intestinal duodenal mucosal cells. CLA decreased serum insulin by 50% (P = 0.02) but increased serum triacylglycerols by over 40%. CLA supplementation increased (P ≤ 0.01) total saturated fatty acids in liver and adipose tissue. In conclusion, neither CLA nor arginine depressed tissue lipid synthesis in growing/finishing pigs, and in fact dietary CLA promoted elevated intramuscular lipid and arginine increased carcass adiposity.
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Sulfide is released in the large intestine lumen by the microbiota and is an inhibitor of mitochondrial respiration and a genotoxic agent in colonocytes when present in excess. Deciphering how colonocytes metabolize sulfide is an important issue. In this study, using the human colonic epithelial HT-29 Glc(-/+) cells, we found that 50 μM sodium hydrogen sulfide represents the threshold of concentration above which respiration is decreased. The capacity of HT-29 Glc(-/+) cells to oxidize lower concentration of sulfide was associated with the expression of transcripts corresponding to the enzymes of the sulfide oxidizing unit (SOU), that is, sulfide quinone reductase (SQR), dioxygenase ethylmalonic encephalopathy, and thiosulfate sulfur transferase (TST). Inhibition of cell O(2) consumption by sulfide was reverted by zinc but not by calcium and iron. When the cells undergo either spontaneous or butyrate-induced differentiation, their capacity to oxidize sulfide was significantly increased. The expression levels of the genes corresponding to the enzymes of the SOU were not increased, whereas increased cellular maximal respiratory capacity and oxygen consumption by the dioxygenase were both measured. In human biopsies recovered from various parts of the large intestine, the three enzymes of the SOU were expressed. SOU and cell respiratory capacity are crucial for sulfide detoxification in colonocytes. Sulfide oxidative capacity in the colonic mucosa is higher in differentiated than in proliferative epithelial cells. The cell respiratory capacity and SOU activity appear to represent major determinants allowing sulfide detoxification in colonic epithelial cells.
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Porcine circovirus type 2 (PCV2) causes reproductive failure in swine. As glutamine can enhance immune function in animals, this study was conducted with mice to test the hypothesis that dietary glutamine supplementation will improve pregnancy outcome in PCV2-infected dams. Beginning on day 0 of gestation, mice were fed a standard diet supplemented with 1.0% L: -glutamine or 1.22% L: -alanine (isonitrogenous control). All mice were infected with PCV2 (2000 TCID(50)) on day 10 of gestation. On day 17 of gestation, six mice from each group were euthanized to obtain maternal tissues and fetuses for hematology and histopathology tests. The remaining mice continued to receive their respective diets supplemented with 1.0% L: -glutamine or 1.22% L: -alanine through lactation. The PCV2 virus was present in maternal samples (serum and lung) of most mice in the control group but was not detected in the glutamine-supplemented mice. Dietary glutamine supplementation reduced abortion, decreased fetal deaths, and enhanced neonatal survival. The glutamine treatment also reduced concentrations of interleukin-6, while increasing concentrations of tumor necrosis factor-α and C-reactive protein, in the maternal serum of mice. Furthermore, glutamine supplementation attenuated microscopic lesions in maternal tissues (lung, spleen, and liver). Collectively, these results indicate that dietary glutamine supplementation is beneficial for ameliorating reproductive failure in virus-infected mice. The findings support the notion that gestating dams require adequate amounts of dietary glutamine for the optimal survival and growth of embryos, fetuses, and neonates, and have important implications for nutritional support of mammals (including swine and humans) during gestation and lactation.
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Amino acids (AA) were traditionally classified as nutritionally essential or nonessential for animals and humans based on nitrogen balance or growth. A key element of this classification is that all nonessential AA (NEAA) were assumed to be synthesized adequately in the body as substrates to meet the needs for protein synthesis. Unfortunately, regulatory roles for AA in nutrition and metabolism have long been ignored. Such conceptual limitations were not recognized until recent seminal findings that dietary glutamine is necessary for intestinal mucosal integrity and dietary arginine is required for maximum neonatal growth and embryonic survival. Some of the traditionally classified NEAA (e.g. glutamine, glutamate, and arginine) play important roles in regulating gene expression, cell signaling, antioxidative responses, and immunity. Additionally, glutamate, glutamine, and aspartate are major metabolic fuels for the small intestine and they, along with glycine, regulate neurological function. Among essential AA (EAA), much emphasis has been placed on leucine (which activates mammalian target of rapamycin to stimulate protein synthesis and inhibit proteolysis) and tryptophan (which modulates neurological and immunological functions through multiple metabolites, including serotonin and melatonin). A growing body of literature leads to a new concept of functional AA, which are defined as those AA that regulate key metabolic pathways to improve health, survival, growth, development, lactation, and reproduction of organisms. Both NEAA and EAA should be considered in the classic "ideal protein" concept or formulation of balanced diets to maximize protein accretion and optimize health in animals and humans.
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L-Glutamine (Gln) plays an important role in sustaining the intestinal mucosal mass of humans and animals. However, the underlying mechanisms are largely unknown. This study tested the hypothesis that Gln regulates protein turnover in intestinal epithelial cells. Intestinal porcine epithelial cells (IPEC-1) were cultured for 3 h (short-term study) or 96 h (long-term study) in Gln-free Dulbecco's modified Eagle-F12 Ham medium containing 0, 0.5 or 2.0 mM Gln. To determine effects of ammonia (a metabolite of Gln, i.e., 0.18 mM ammonia produced from 2 mM Gln in 3 h) on protein turnover, additional experiments were conducted in which medium contained 0.5 mM Gln and 0, 0.2, 0.5 or 2.0 mM NH(4)Cl. Variables of analysis included cell growth, protein synthesis, proteolysis and mammalian target of rapamycin (mTOR) signaling. IPEC-1 cell growth increased with extracellular Gln concentrations. Compared with 0 mM Gln, the addition of 0.5 and 2 mM Gln to medium stimulated protein synthesis and inhibited protein degradation in those cells in both the short- and long-term studies. Ammonia (0.05 to 2.0 mM) did not affect protein synthesis, although higher levels of ammonia (0.5 and 2.0 mM) reduced protein degradation in IPEC-1 cells. Consistent with the data on protein turnover, 0.5 and 2 mM Gln increased abundance of phosphorylated eIF4E-binding protein-1 and phosphorylated S6 kinase-1 proteins. Collectively, these results demonstrate that physiological levels of Gln regulate protein turnover independent of ammonia production in intestinal cells through the mTOR signaling pathway.
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Morphological differentiation of uterine glands in mammals is a postnatal event vulnerable to adverse effects of endocrine disruptors. Exposure of ewe lambs to a progestin from birth to postnatal day 56 prevents development of uterine glands and, as adults, the ewes are unable to exhibit estrous cycles or maintain pregnancy. Uterine epithelia secrete proteins and transport nutrients into the uterine lumen necessary for conceptus development, pregnancy recognition signaling and implantation, including arginine and secreted phosphoprotein 1 (SPP1). Arginine can be metabolized to nitric oxide and to polyamines or act directly to activate MTOR cell signaling to stimulate proliferation, migration, and mRNA translation in trophectoderm cells. SPP1 binds αvβ3 and α5β1 integrins and induces focal adhesion assembly, adhesion and migration of conceptus trophectoderm cells during implantation. Thus, arginine and SPP1 mediate growth, migration, cytoskeletal remodeling and adhesion of trophectoderm essential for pregnancy recognition signaling and implantation.
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α-Ketoglutarate (AKG) is a key intermediate in glutamine metabolism. Emerging evidence shows beneficial effects of AKG on clinical and experimental nutrition, particularly with respect to intestinal growth and integrity. However, the underlying mechanisms are unknown. Intestinal porcine epithelial cells (IPEC-1) were used to test the hypothesis that AKG inhibits glutamine degradation and enhances protein synthesis. IPEC-1 cells were cultured for 3 days in Dulbecco's modified Eagle's-F12 Ham medium (DMEM-F12) containing 0, 0.2, 0.5 or 2 mM of AKG. At the end of the 3-day culture, cells were used to determine L-[U-14C]glutamine utilization, protein concentration, protein synthesis, and the total and phosphorylated levels of the mammalian target of the rapamycin (mTOR), ribosomal protein S6 kinase-1 (S6K1) and eukaryotic initiation factor (eIF) 4E-binding protein-1 (4E-BP1). Compared with 0 mM of AKG (control), 0.2 and 0.5 mM of AKG dose-dependently reduced (P<0.05) glutamine degradation and the production of glutamate, alanine and aspartate in IPEC-1 cells. Addition of 0.5 and 2 mM of AKG to culture medium enhanced protein synthesis (P<0.05) by 78 and 101% without affecting protein degradation, compared to the control group. Rapamycin (50 nM; a potent inhibitor of mTOR) attenuated the stimulatory effect of AKG on protein synthesis. Consistent with these metabolic data, the addition of 0.5 or 2 mM of AKG to culture medium increased (P<0.05) the phosphorylated levels of mTOR, S6k1 and 4E-BP1 proteins. Collectively, these results indicate that AKG can spare glutamine and activate the mTOR signaling pathway to stimulate protein synthesis in intestinal epithelial cells.
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Macronutrients, such as protein or amino acid, not only supply calories but some components may also play as signaling molecules to affect feeding behavior, energy balance, and fuel efficiency. Leucine, a branched-chain amino acid is a good example. After structural roles are satisfied, the ability of leucine to function as signal and oxidative substrate is based on a sufficient intracellular concentration. Therefore, leucine level must be sufficiently high to play the signaling and metabolic roles. Leucine is not only a substrate for protein synthesis of skeletal muscle, but also plays more roles beyond that. Leucine activates signaling factor of mammalian target of rapamycin (mTOR) to promote protein synthesis in skeletal muscle and in adipose tissue. It is also a major regulator of the mTOR sensitive response of food intake to high protein diet. Meanwhile, leucine regulates blood glucose level by promoting gluconeogenesis and aids in the retention of lean mass in a hypocaloric state. It is beneficial to animal nutrition and clinical application and extrapolation to humans.
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Placental vascular formation and blood flow are crucial for fetal survival, growth and development, and arginine regulates vascular development and function. This study determined the effects of dietary arginine or N-carbamylglutamate (NCG) supplementation during late gestation of sows on the microRNAs, vascular endothelial growth factor A (VEGFA) and endothelial nitric oxide synthase (eNOS) expression in umbilical vein. Twenty-seven landrace×large white sows at day (d) 90 of gestation were assigned randomly to three groups and fed the following diets: a control diet and the control diet supplemented with 1.0% L-arginine or 0.10% NCG. Umbilical vein of fetuses with body weight around 2.0 kg (oversized), 1.5 kg (normal) and 0.6 kg (intrauterine growth restriction, IUGR) were obtained immediately after farrowing for miR-15b, miR-16, miR-221, miR-222, VEGFA and eNOS real-time PCR analysis. Compared with the control diets, dietary Arg or NCG supplementation enhanced the reproductive performance of sows, significantly increased (P<0.05) plasma arginine and decreased plasma VEGF and eNOS (P<0.05). The miR-15b expression in the umbilical vein was higher (P<0.05) in the NCG-supplemented group than in the control group. There was a trend in that the miR-222 expression in the umbilical vein of the oversized fetuses was higher (0.05<P<0.1) than in the normal and IUGR fetuses. The expression of eNOS in both Arg-supplemented and NCG-supplemented group were lower (P<0.05) than in the control group. The expression of VEGFA was higher (P<0.05) in the NCG-supplemented group than in the Arg-supplemented and the control group. Meanwhile, the expression of VEGFA of the oversized fetuses was higher (P<0.05) than the normal and IUGR fetuses. In conclusion, this study demonstrated that dietary Arg or NCG supplementation may affect microRNAs (miR-15b, miR-222) targeting VEGFA and eNOS gene expressions in umbilical vein, so as to regulate the function and volume of the umbilical vein, provide more nutrients and oxygen from the maternal to the fetus tissue for fetal development and survival, and enhance the reproductive performance of sows.
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This paper reviews and interprets a method for determining the nutritional value of D-amino acids, D-peptides, and amino acid derivatives using a growth assay in mice fed a synthetic all-amino acid diet. A large number of experiments were carried out in which a molar equivalent of the test compound replaced a nutritionally essential amino acid such as L-lysine (L-Lys), L-methionine (L-Met), L-phenylalanine (L-Phe), and L-tryptophan (L-Trp) as well as the semi-essential amino acids L-cysteine (L-Cys) and L-tyrosine (L-Tyr). The results show wide-ranging variations in the biological utilization of test substances. The method is generally applicable to the determination of the biological utilization and safety of any amino acid derivative as a potential nutritional source of the corresponding L-amino acid. Because the organism is forced to use the D-amino acid or amino acid derivative as the sole source of the essential or semi-essential amino acid being replaced, and because a free amino acid diet allows better control of composition, the use of all-amino-acid diets for such determinations may be preferable to protein-based diets. Also covered are brief summaries of the widely scattered literature on dietary and pharmacological aspects of 27 individual D-amino acids, D-peptides, and isomeric amino acid derivatives and suggested research needs in each of these areas. The described results provide a valuable record and resource for further progress on the multifaceted aspects of D-amino acids in food and biological samples.
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Bacteria in the gastrointestinal (GI) tract play an important role in the metabolism of dietary substances in the gut and extraintestinal tissues. Amino acids (AA) should be taken into consideration in the development of new strategies to enhance efficiency of nutrient utilization because they are not only major components in the diet and building blocks for protein but also regulate energy and protein homeostasis in organisms. The diversity of the AA-fermenting bacteria and their metabolic redundancy make them easier to survive and interact with their neighboring species or eukaryotic host during transition along GI tract. The outcomes of the interactions have important impacts on gut health and whole-body homeostasis. The AA-derived molecules produced by intestinal bacteria affect host health by regulating either host immunity and cell function or microbial composition and metabolism. Emerging evidence shows that dietary factors, such as protein, non-digestible carbohydrates, probiotics, synbiotics and phytochemicals, modulate AA utilization by gut microorganisms. Interdisciplinary research involving nutritionists and microbiologists is expected to rapidly expand knowledge about crucial roles for AA in gut ecology and host health.
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Glutamine is the most abundant free alpha-amino acid in plasma and skeletal muscle. This nutrient plays an important role in regulating gene expression, protein turnover, anti-oxidative function, nutrient metabolism, immunity, and acid-base balance. Interestingly, intracellular and extracellular concentrations of glutamine exhibit marked reductions in response to infection, sepsis, severe burn, cancer, and other pathological factors. This raised an important question of whether glutamine may be a key mediator of muscle loss and negative nitrogen balance in critically ill and injured patients. Therefore, since the initial reports in late 1980s that glutamine could stimulate protein synthesis and inhibit proteolysis in rat skeletal muscle, there has been growing interest in the use of this functional amino acid to improve protein balance under various physiological and disease conditions. Although inconsistent results have appeared in the literature regarding a therapeutic role of glutamine in clinical medicine, a majority of studies indicate that supplementing appropriate doses of glutamine to enteral diets or parenteral solutions is beneficial for improving nitrogen balance in animals or humans with glutamine deficiency.
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L-Glutamine (Gln) has traditionally not been considered a nutrient needed in diets for livestock species or even mentioned in classic animal nutrition textbooks. This is due to previous technical difficulties in Gln analysis and the unsubstantiated assumption that animals can synthesize sufficient amounts of Gln to meet their needs. Consequently, the current (1998) version of NRC does not recommend dietary Gln requirements for swine. This lack of knowledge about Gln nutrition has contributed to suboptimal efficiency of global pig production. Because of recent advances in research, Gln is now known to be an abundant AA in physiological fluids and proteins and a key regulator of gene expression. Additionally, Gln can regulate cell signaling via the mammalian target of rapamycin pathway, adenosine monophosphate-activated protein kinase, extracellular signal-related kinase, Jun kinase, mitogen-activated protein kinase, and nitric oxide. The exquisite integration of Gln-dependent regulatory networks has profound effects on cell proliferation, differentiation, migration, metabolism, homeostasis, survival, and function. As a result of translating basic research into practice, dietary supplementation with 1% Gln maintains gut health and prevents intestinal dysfunction in low-birth-weight or early-weaned piglets while increasing their growth performance and survival. In addition, supplementing 1% Gln to a corn- and soybean-meal-based diet between d 90 and 114 of gestation ameliorates fetal growth retardation in gilts and reduces preweaning mortality of piglets. Furthermore, dietary supplementation with 1% Gln enhances milk production by lactating sows. Thus, adequate amounts of dietary Gln, a major nutrient, are necessary to support the maximum growth, development, and production performance of swine.
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The objective of this study was to determine developmental changes in mRNA and protein levels for N-acetylglutamate synthase (NAGS; a key enzyme in synthesis of citrulline and arginine from glutamine/glutamate and proline) in the small intestine of suckling piglets. The porcine NAGS gene was cloned using the real-time polymerase-chain reaction (RT-PCR) method. The porcine NAGS gene encoded 368 amino acid residues and had a high degree of sequence similarity to the "conserved domain" of human and mouse NAGS genes. The porcine NAGS gene was expressed in E. coli BL21 and a polyclonal antibody against the porcine NAGS protein was developed. Real-time RT-PCR and western-blot analyses were performed to quantify NAGS mRNA and protein, respectively, in the jejunum and ileum of 1- to 28-day-old pigs. Results indicated that intestinal NAGS mRNA levels were lower in 7- to 28-day-old than in 1-day-old pigs. Immunochemical analysis revealed that NAGS protein was localized in enterocytes of the gut. Notably, intestinal NAGS protein abundance declined progressively during the 28-day suckling period. The postnatal decrease in NAGS protein levels was consistent with the previous report of reduced NAGS enzymatic activity as well as reduced synthesis of citrulline and arginine in the small intestine of 7- to 28-day-old pigs. Collectively, these results suggest that intestinal NAGS expression is regulated primarily at the post-transcriptional level. The findings also provide a new molecular basis to explain that endogenous synthesis of arginine is impaired in sow-reared piglets and arginine is a nutritionally essential amino acid for the neonates.
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Amino acid biochemistry and nutrition spans a broad range of fields including biochemistry, metabolism, physiology, immunology, reproduction, pathology, and cell biology. In the last half-century, there have been many conceptual and technical advancements, from analysis of amino acids by high-performance liquid chromatography and mass spectrometry to molecular cloning of transporters for amino acids and small peptides. Amino Acids: Biochemistry and Nutrition presents comprehensive coverage of these scientific developments, providing a useful reference for students and researchers in both biomedicine and agriculture. The text begins with the discoveries and basic concepts of amino acids, peptides, and proteins, and then moves to protein digestion and absorption of peptides and amino acids. Additional chapters cover cell-, tissue-, and species-specific synthesis and catabolism of amino acids and related nitrogenous substances, as well as the use of isotopes to study amino acid metabolism in cells and the body. The book also details protein synthesis and degradation, regulation of amino acid metabolism, physiological functions of amino acids, and inborn errors of amino acid metabolism. The final chapter discusses dietary requirements of amino acids by humans and other animals. While emphasizing basic principles and classical concepts of amino acid biochemistry and nutrition, the author includes recent progress in the field. This book also provides concise coverage of major historical developments of the scientific discipline, so that readers will appreciate the past, understand the current state of the knowledge, and explore the future of the field. Each chapter contains select references to provide comprehensive reviews and original experimental data on the topics discussed.
Article
This study was conducted to determine the immunostimulatory effect of L-proline on inactivated vaccine immunized mice. Ninety-five female KM mice were randomly divided into five groups: (1) mice received dietary supplementation with 0.4 % L-proline and immunized with inactivated vaccine (V-P group); (2) mice received dietary supplementation with 0.3 % L-alanine (isonitrogenous control) and immunized with inactivated vaccine (V-A group, negative control); (3) mice were immunized with inactivated vaccine with oil adjuvant (V-O group, positive control); (4) mice were immunized with inactivated vaccine with aluminum hydroxide adjuvant (V-H group, positive control); (5) mice immunized with phosphate-buffered saline (control group). All mice were dead in the control group between 36 and 48 h post infection. Mice in the V-P group showed 100 % protection after challenge with P. multocida serotype A (CQ2) at dose of 4.4 × 10(5) CFU (2LD50). Meanwhile, serum antibody titers in the V-P group were higher than those in the V-A group before infection and those in the V-A and V-O groups at 36 h post infection. Moreover, serum IL-1β levels in the V-P group were lower than those in V-O group. Furthermore, serum GSH-PX levels in the V-P group were higher than those in the V-A and V-O groups. Collectively, dietary proline supplementation confers beneficial immunostimulatory effects in inactivated P. multocida vaccine immunized mice.
Article
Mammalian target of rapamycin (mTOR) is a conserved Ser/Thr kinase that is part of mTOR complex 1 (mTORC1), a master regulator that couples amino acid availability to cell growth and autophagy. Multiple cues modulate mTORC1 activity, such as growth factors, stress, energy status and amino acids. Although amino acids are key environmental stimuli, exactly how they are sensed and how they activate mTORC1 is not fully understood. Recently, a model has emerged whereby mTORC1 activation occurs at the lysosome and is mediated through an amino acid sensing cascade involving RAG GTPases, Ragulator and vacuolar H(+)-ATPase (v-ATPase).
Article
DR (dietary restriction), or reduced food intake without malnutrition, is associated with extended longevity, improved metabolic fitness and increased stress resistance in a wide range of organisms. DR is often referred to as calorie restriction, implying that reduced energy intake is responsible for its widespread and evolutionarily conserved benefits. However, recent data indicate dietary amino acid restriction as a key mediator of DR benefits. In fruitflies, an imbalance in essential amino acid intake is thought to underlie longevity benefits of DR. In mammals, reduced dietary protein or essential amino acid intake can extend longevity, improve metabolic fitness and increase stress resistance. In the present paper we review two evolutionarily conserved signal transduction pathways responsible for sensing amino acid levels. The eIF2α (eukaryotic initiation factor 2α) kinase GCN2 (general amino acid control non-derepressible 2) senses the absence of one or more amino acids by virtue of direct binding to uncharged cognate tRNAs. The presence of certain amino acids, such as leucine, permits activation of the master growth regulating kinase TOR (target of rapamycin). These two signal transduction pathways react to amino acid deprivation by inhibiting general protein translation while at the same time increasing translation of specific mRNAs involved in restoring homoeostasis. Together, these pathways may contribute to the regulation of longevity, metabolic fitness and stress resistance.
Article
Dietary intake of glutamate by postweaning pigs is markedly reduced due to low feed consumption. This study was conducted to determine the safety and efficacy of dietary supplementation with monosodium glutamate (MSG) in postweaning pigs. Piglets were weaned at 21 days of age to a corn and soybean meal-based diet supplemented with 0, 0.5, 1, 2, and 4 % MSG (n = 25/group). MSG was added to the basal diet at the expense of cornstarch. At 42 days of age (21 days after weaning), blood samples (10 mL) were obtained from the jugular vein of 25 pigs/group at 1 and 4 h after feeding for hematological and clinical chemistry tests; thereafter, pigs (n = 6/group) were euthanized to obtain tissues for histopathological examinations. Feed intake was not affected by dietary supplementation with 0-2 % MSG and was 15 % lower in pigs supplemented with 4 % MSG compared with the 0 % MSG group. Compared with the control, dietary supplementation with 1, 2 and 4 % MSG dose-dependently increased plasma concentrations of glutamate, glutamine, and other amino acids (including lysine, methionine, phenylalanine and leucine), daily weight gain, and feed efficiency in postweaning pigs. At day 7 postweaning, dietary supplementation with 1-4 % MSG also increased jejunal villus height, DNA content, and antioxidative capacity. The MSG supplementation dose-dependently reduced the incidence of diarrhea during the first week after weaning. All variables in standard hematology and clinical chemistry tests, as well as gross and microscopic structures, did not differ among the five groups of pigs. These results indicate that dietary supplementation with up to 4 % MSG is safe and improves growth performance in postweaning pigs.
Article
Brown adipose tissue (BAT), which is present in humans, plays an important role in oxidation of fatty acids and glucose. The purpose of this review is to highlight an important role for L-arginine in regulating BAT growth and development, thereby reducing obesity in mammals. Dietary supplementation with L-arginine reduces white adipose tissue in genetically or diet-induced obese rats, obese pregnant sheep, and obese humans with type II diabetes. L-arginine treatment enhances BAT growth in both fetuses and postnatal animals. At molecular and cellular levels, L-arginine stimulates expression of peroxisome proliferator-activated receptor-γ coactivator 1 (the master regulator of mitochondrial biogenesis), nitric oxide synthase, heme oxygenase, and adenosine monophosphate-activated protein kinase. At the whole body level, L-arginine increases blood flow to insulin-sensitive tissues, adipose tissue lipolysis, and the catabolism of glucose and fatty acids, but inhibits fatty acid synthesis and ameliorates oxidative stress, thereby improving metabolic profile. L-arginine increases mammalian BAT growth and development via mechanisms involving gene expression, nitric oxide signaling, and protein synthesis. This enhances the oxidation of energy substrates and, thus, reduces white fat accretion in the body. L-arginine holds great promise in preventing and treating obesity in humans.
Article
Rapid progress in gastroenterology during the first part of the last century has shown that gastrointestinal (GI) function is regulated by neuroendocrine, paracrine and endocrine signals. However, recent advances in chemical sensing, especially in the last decade, have revealed that free L: -amino acids (AA), among other nutrients, play a critical role in modifying exocrine and endocrine secretion, modulating protein digestion, metabolism and nutrient utilization, and supporting the integrity and defense of the GI mucosa. Many of the mechanisms by which AAs elicit these functions in the GI has been linked to the traditional concept of hormone release and nervous system activation. But most these effects are not direct. AAs appear to function by binding to a chemical communication system such as G protein-coupled receptors (GPCRs) that activate signaling pathways. These intracellular signals, although their molecular bases are not completely elucidated yet, are the ones responsible for the neuronal activity and release of hormones that in turn regulate GI functions. This review aims to describe the distribution of the known GPCRs from the class 3 superfamily that bind to different kinds of AA, especially from the oropharyngeal cavity to the stomach, what kind of taste qualities they elicit, such as umami, bitter or sweet, and their activity in the GI tract.
Article
The ingestion of large neutral amino acids (LNAA), notably tryptophan, tyrosine and the branched-chain amino acids (BCAA), modifies tryptophan and tyrosine uptake into brain and their conversion to serotonin and catecholamines, respectively. The particular effect reflects the competitive nature of the transporter for LNAA at the blood-brain barrier. For example, raising blood tryptophan or tyrosine levels raises their uptake into brain, while raising blood BCAA levels lowers tryptophan and tyrosine uptake; serotonin and catecholamine synthesis in brain parallel the tryptophan and tyrosine changes. By changing blood LNAA levels, the ingestion of particular proteins causes surprisingly large variations in brain tryptophan uptake and serotonin synthesis, with minimal effects on tyrosine uptake and catecholamine synthesis. Such variations elicit predictable effects on mood, cognition and hormone secretion (prolactin, cortisol). The ingestion of mixtures of LNAA, particularly BCAA, lowers brain tryptophan uptake and serotonin synthesis. Though argued to improve physical performance by reducing serotonin function, such effects are generally considered modest at best. However, BCAA ingestion also lowers tyrosine uptake, and dopamine synthesis in brain. Increasing dopamine function in brain improves performance, suggesting that BCAA may fail to increase performance because dopamine is reduced. Conceivably, BCAA administered with tyrosine could prevent the decline in dopamine, while still eliciting a drop in serotonin. Such an LNAA mixture might thus prove an effective enhancer of physical performance. The thoughtful development and application of dietary proteins and LNAA mixtures may thus produce treatments with predictable and useful functional effects.
Article
This study tested the hypothesis that an increase in arginine concentration in the portal vein may affect blood flow and oxygen consumption in the portal-drained viscera (PDV) of swine. Eight barrows (70 kg body weight) were surgically fitted with chronic catheters in the portal vein, ileal vein, and carotid artery. Thirteen days after the surgery, pigs that had been fasted for 12 h were randomly allocated to receive administration of either L: -alanine (103 mg/kg body weight, isonitrogenous control) or L: -arginine-HCl (61 mg/kg body weight) via the portal vein. Portal vein blood flow (PVBF) was measured with infusion of p-aminohippuric acid into the ileal vein, and blood samples were simultaneously obtained every 0.5 h for 4 h. Compared with the control, arginine infusion increased PVBF at 30-90 min after infusion but decreased PDV oxygen consumption at 60-150 min after infusion (P < 0.05). Plasma concentrations of glutamate at infusion times of 180-240 min and of arginine at infusion times of 60-240 min in arginine-infused pigs were higher than those for the control group (P < 0.05). Plasma concentrations of insulin and glucagon at the infusion times of 30-90 min were higher and of free fatty acids at the infusion times of 60-120 min were lower than those for the control pigs (P < 0.05). These results indicate that increasing arginine concentration in the portal vein enhances PDV blood flow, reduces PDV oxygen consumption, and beneficially alters the metabolic profile in swine, an established animal model for studying human nutrition and metabolism.