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John A Rathmacher

John A Rathmacher
MTI BioTech Inc.

PhD

About

101
Publications
23,571
Reads
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3,259
Citations
Additional affiliations
July 1996 - December 2019
Metabolic Technologies Inc.
Metabolic Technologies Inc.
Position
  • Senior Researcher
December 1993 - September 1996
Iowa State University
Position
  • PostDoc Position

Publications

Publications (101)
Article
Full-text available
Previous university studies demonstrated that supplementing sows with calcium beta-hydroxy-beta-methylbutyrate (CaHMB) in late gestation and/or lactation improved piglet weights through weaning. Two studies were conducted at commercial farrowing operations to test if the results would translate to commercial operations. Sows in both trials were ran...
Article
The age-related loss of skeletal muscle mass, quality, and strength can lead to the loss of independence later in life. Beta-hydroxy-beta-methylbutyrate (HMB), a leucine metabolite, can increase skeletal muscle size and function. However, emerging evidence suggests HMB may be less effective at improving muscle function in people with insufficient V...
Article
Previous studies have shown that supplementing sows with calcium beta-hydroxy-beta-methylbutyrate (CaHMB) or CaHMB plus Vitamin D3 in late gestation and/or lactation improved piglet weight through weaning. This study was conducted at a commercial farrowing operation to confirm previous results, and 52 sows were studied, 26 in each of 2 groups. Sows...
Article
The leucine metabolite, 3-hydroxy-3-methylbutyrate (HMB), primarily utilized as the calcium salt (CaHMB) has become one of the most widely used supplements and food ingredients to promote muscle health. While both CaHMB and HMB free acid have published sub-chronic toxicity studies, and CaHMB has published studies on genotoxicity, data are lacking o...
Article
Full-text available
Background: Chronic oral ATP supplementation benefits cardiovascular health, muscular performance, body composition, and recovery while attenuating muscle breakdown and fatigue. A single 400 mg dose of oral ATP supplementation improved lower body resistance training performance and energy expenditure in recreational resistance trained males, howeve...
Article
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Background Although catheter ablation is an effective therapy for atrial fibrillation (AF), the most common cardiac arrhythmia encountered in clinical practice, AF ablation generates inflammation and oxidative stress in the early postoperative period predisposing to recurrence of AF. Isolevuglandins (IsoLGs) are reactive lipid mediators of oxidativ...
Article
Full-text available
Leucine is regarded as an anabolic trigger for the mTORC1 pathway and the stimulation muscle protein synthesis rates. More recently, there has been an interest in underpinning the relevance of BCAA-containing dipeptides and their intact absorption into circulation to regulate muscle anabolic responses. We investigated the effects of dileucine and l...
Article
Several university studies supplementing calcium beta-hydroxy-beta-methylbutyrate (CaHMB) to sows have reported benefit to piglets such as a reduction in low birthweight piglets, increased piglet birth weight, and increased weaning weights. This study was designed to determine if these benefits would be observed in a commercial production setting u...
Article
Full-text available
Adenosine triphosphate (ATP) is the primary compound that provides energy to drive many processes in living cells, including muscle contraction, neurotransmission, and cardiac function. Initial research used enteric-coated ATP that displayed no apparent efficacy. However, ATP disodium supplementation has demonstrated improved bioavailability and ac...
Article
Full-text available
Insulin resistance (IR) is a key feature in the development of numerous metabolic diseases. The cornerstone for treatment for IR remains diet and exercise, however these have poor rates of adherence. Beta-hydroxy-beta-methylbutyrate (HMB) is a nutraceutical with contentious effects on IR in animal models. The aim of this study was to evaluate the i...
Article
Full-text available
The effects of resistance training (RT) associated with calcium β-hydroxy-β-methylbutyrate (CaHMB) supplementation on the body composition and gene expression of cytokines related to skeletal muscle hypertrophy and adipose tissue metabolism were studied in rats. Male Wistar rats were divided into four groups of 12 animals: sedentary control (SC); s...
Article
Full-text available
The primary aim of this study was to determine whether supplementation with calcium β-hydroxy-β-methylbutyrate (HMB) and Vitamin D3 (D) would enhance muscle function and strength in older adults. Older adults over 60 years of age with insufficient circulating 25-hydroxy-Vitamin D (25OH-D) levels were enrolled in a double-blinded controlled 12-month...
Article
Full-text available
Background: 2-Hydroxybenzylamine (2-HOBA) is a selective dicarbonyl electrophile scavenger being developed as a nutritional supplement to help protect against the development of conditions associated with dicarbonyl electrophile formation, such as the cognitive decline observed with Mild Cognitive Impairment or Alzheimer's disease. Methods: This...
Article
Carnosine and histidine content in the hippocampus of 14-month-old male rats was examined following 30 days of β-alanine supplementation. All animals were provided identical diets; however, 100 mg of β-alanine was mixed with glucomannan (80:20 blend) in the water of β-alanine supplemented animals. Hippocampal carnosine content was significantly gre...
Article
Full-text available
Background 2-Hydroxybenzylamine (2-HOBA) is a selective scavenger of dicarbonyl electrophiles that protects proteins and lipids from being modified by these electrophiles. It is currently being developed for use as a nutritional supplement to help maintain good health and protect against the development of conditions associated with dicarbonyl elec...
Article
Full-text available
2-hydroxybenzylamine (2-HOBA), a naturally occurring compound found in buckwheat, has potential for use as a nutrition supplement due to its ability to protect against the damaging effects of oxidative stress. In a series of rodent toxicity studies, 2-HOBA acetate was well-tolerated and did not produce any toxic effects over 28 or 90 days of repeat...
Article
β-Hydroxy-β-methylbutyrate (HMB) is a leucine metabolite available in calcium salt (CaHMB) and free acid forms as a sports nutrition ergogenic aid. HMB has also been used to support muscle health in the elderly and other populations needing to maintain muscle mass. Several human studies have reported safety data for CaHMB, and rodent sub-chronic to...
Article
2-hydroxybenzylamine (2-HOBA), a compound found in buckwheat, is a potent scavenger of reactive γ-ketoaldehydes, which are increased in diseases associated with inflammation and oxidative stress. While the potential of 2-HOBA is promising, studies were needed to characterize the safety of the compound before clinical trials. In a series of experime...
Article
Full-text available
2-hydroxybenzylamine (2-HOBA), a naturally occurring compound found in buckwheat, can protect cells and tissues from oxidative stress. In this study, 2-HOBA acetate was orally administered to male and female rats for 90 consecutive days at doses of 100, 500, and 1000 mg kg BW-1·d-1 (n = 20 per sex/group). Subchronic administration of 2-HOBA was wel...
Article
Full-text available
Age-related sarcopenia and dynapenia are associated with frailty and metabolic diseases Resistance exercise training (RET) adjuvant to evidence-based nutritional intervention(s) have been shown as mitigating strategies. Given that b-hydroxy-b-methyl-butyrate (HMB) supplementation during RET improves lean body mass in younger humans, and that we hav...
Article
Full-text available
2-hydroxybenzylamine (2-HOBA), a compound naturally found in buckwheat, has been shown to protect cells and tissues from the damaging effects of oxidative stress. The purpose of this report was to evaluate 2-HOBA in preclinical oral rodent toxicity studies. This report includes the results from three oral toxicity studies in rodents: a preliminary...
Article
Background & aims β-hydroxy-β-methylbutyrate (HMB) is purported as a key nutritional supplement for the preservation of muscle mass in health, disease and as an ergogenic aid in exercise. Of the two available forms of HMB (calcium (Ca-HMB) salt or free acid (FA-HMB)) – differences in plasma bioavailability have been reported. We previously reported...
Article
Previous studies have assessed vitamin D status based on the 25-hydroxyvitamin D [25(OH)D] concentration measured in samples from dried blood spots (DBSs). In 40 individuals participating in a clinical study, we compared 25(OH)D levels measured from DBSs and in serum using an LC-MS/MS reference procedure in collaboration with the Vitamin D Standard...
Article
Objective: Oral adenosine-5'-triphosphate (ATP) administration has failed to increase plasma ATP levels; however, chronic supplementation with ATP has shown to increase power, strength, lean body mass, and blood flow in trained athletes. The purpose of this study was to investigate the effects of ATP supplementation on postexercise ATP levels and...
Article
Full-text available
Adenosine-5'-triphosphate (ATP) supplementation helps maintain performance under high fatiguing contractions and with greater fatigue recovery demands also increase. Current evidence suggests that the free acid form of β-hydroxy-β-methylbutyrate (HMB-FA) acts by speeding regenerative capacity of skeletal muscle following high intensity or prolonged...
Article
β-Hydroxy-β-methylbutyrate (HMB), a leucine metabolite, has long been supplemented as a Ca salt (Ca-HMB) to increase strength and performance gains with exercise and to reduce recovery time. Recently, the free acid form of HMB (HMB-FA) has become commercially available in capsule form (gelcap). The current study was conducted to compare the bioavai...
Article
Full-text available
The purpose of this study was to examine if L-leucine (Leu), β-hydroxy-β-methylbutyrate (HMB), or creatine monohydrate (Crea) prevented potential atrophic effects of myostatin (MSTN) on differentiated C2C12 myotubes. After four days of differentiation, myotubes were treated with MSTN (10 ng/ml) for two additional days and four treatment groups were...
Article
Full-text available
Introduction Extracellular adenosine triphosphate (ATP) stimulates vasodilation by binding to endothelial ATP-selective P2Y2 receptors; a phenomenon, which is posited to be accelerated during exercise. Herein, we used a rat model to examine how different dosages of acute oral ATP administration affected the femoral blood flow response prior to, dur...
Article
Full-text available
Studies utilizing beta-hydroxy-beta-methylbutyrate (HMB) supplementation in trained populations are limited. No long-term studies utilizing HMB free acid (HMB-FA) have been conducted. Therefore, we investigated the effects of 12 weeks of HMB-FA supplementation on skeletal muscle hypertrophy, body composition, strength, and power in trained individu...
Article
Full-text available
Calcium β-hydroxy-β-methylbutyrate-monohydrate (CaHMB) is a dietary supplement used as an ergogenic aid and in functional and medical foods. A new delivery form has been developed, β-hydroxy-β-methylbutyric free acid (HMBFA), which has improved bioavailability. While the safety of CaHMB is well documented, there are few published studies demonstrat...
Article
Full-text available
Currently, there is a lack of studies examining the effects of adenosine-5'-triphosphate (ATP) supplementation utilizing a long-term, periodized resistance-training program (RT) in resistance-trained populations. Therefore, we investigated the effects of 12 weeks of 400 mg per day of oral ATP on muscular adaptations in trained individuals. We also...
Article
Full-text available
Skeletal muscle loss accompanying aging or cancer is associated with reduced physical function and predicts morbidity and mortality. 3-Methylhistidine (3MH) has been proposed as a biomarker of myofibrillar proteolysis, which may contribute to skeletal muscle loss. We hypothesized that the terminal portion of the isotope decay curve following an ora...
Conference Paper
Full-text available
Introduction Adenosine-Triphosphate (ATP) supplementation maintains performance and increases volume under high fatiguing contractions. However, greater fatigue increases recovery demands between training sessions. Studies utilizing HMB free acid (HMB-FA) supplementation suggest that the supplement speeds regenerative capacity. However, we are unaw...
Conference Paper
Full-text available
Introduction Extracellular adenosine triphosphate (ATP) is hypothesized to stimulate vasodilation by binding to endothelial ATP/UTP-selective P2Y2 receptors; a phenomenon which is posited to be accelerated during exercise. Nonetheless, no studies to our knowledge have delineated if supplemental ATP enhances the blood flow response to exercise. Here...
Article
Full-text available
Maintenance of skeletal muscle mass is contingent upon the dynamic equilibrium (fasted losses-fed gains) in protein turnover. Of all nutrients, the single amino acid Leucine (Leu) possesses the most marked anabolic characteristics in acting as a trigger element for the initiation of protein synthesis. While the mechanisms by which Leu is "sensed" h...
Article
Full-text available
The purpose of the present study was to determine the effects of short-term supplementation with the free acid form of β-hydroxy-β-methylbutyrate (HMB-FA) on indices of muscle damage, protein breakdown, recovery and hormone status following a high-volume resistance training session in trained athletes. A total of twenty resistance-trained males wer...
Article
Full-text available
Background Beta-hydoxy-beta-methyl butyrate (HMB) when given over a two-week period of time (loading phase) has been demonstrated to decrease skeletal muscle damage, and improve recovery. However, few studies have investigated its acute effects on muscle damage and recovery. Therefore the purpose of this investigation was to determine the effects o...
Article
Full-text available
Results There were no differences in total calories, protein, carbohydrate, or fat consumed between groups. There were time, and group x time effects (p<0.05) for total strength, which increased by a greater percentage in the HMB (430.4 ±2 2.5 to 507.5 ±2 1.7 kg; +1 8.3 %) than the placebo group (422.2 ± 24.9 to 447.5 ± 22.5 kg; + 6.6 %). There wer...
Article
Full-text available
The marine organism Moritella marina MP-1 produces the polyunsaturated fatty acid docosahexaenoic acid (DHA). While the basic metabolic pathway for DHA production in this organism has been identified, the impact of growth conditions on DHA production is largely unknown. This study examines the effect of supplemental carbon, nitrogen and salts, grow...
Article
Full-text available
Background Intracellular concentrations of adenosine-5’-triphosphate (ATP) are many times greater than extracellular concentrations (1–10 mM versus 10–100 nM, respectively) and cellular release of ATP is tightly controlled. Transient rises in extracellular ATP and its metabolite adenosine have important signaling roles; and acting through purinergi...
Data
Table S1. Blood chemistry values before and after 15 days of supplementation with either a placebo or 400 mg ATP/d.*Table S2. Blood hematology values before and after 15 days of supplementation with either a placebo or 400 mg ATP/d.*
Article
Full-text available
Older adults supplemented for 1 year with β-hydroxy-β-methylbutyrate, arginine, and lysine (HMB/ARG/LYS) were previously shown to have significant gains in fat-free mass (FFM) but not muscular strength. Recently, increasing levels of serum vitamin D have been associated with an increase in muscle function, particularly in the elderly. To determine...
Article
Full-text available
The purpose of this study was to determine if PKB signaling is decreased and contractile protein degradation is increased in extensor digitorum longus (EDL) and soleus (SOL) muscles from middle-aged (MA) and aged (AG) mice. We also examined the effect of age on atrogene expression in quadriceps muscle. PKB activity, as assessed by Thr(308) and Ser(...
Article
Nuclear magnetic resonance (NMR)-based metabolomic profiling identified urinary 1- and 3-methylhistidine (1- and 3-MH) as potential biomarkers of skeletal muscle toxicity in Sprague-Dawley rats following 7 and 14 daily doses of 0.5 or 1mg/kg cerivastatin. These metabolites were highly correlated to sex-, dose- and time-dependent development of ceri...
Article
Full-text available
The leucine metabolite, β-hydroxy-β-methylbutyrate (HMB), is a nutritional supplement that increases lean muscle and strength with exercise and in disease states. HMB is presently available as the Ca salt (CaHMB). The present study was designed to examine whether HMB in free acid gel form will improve HMB availability to tissues. Two studies were c...
Article
Roux-en-Y gastric bypass (RYGB) surgery has become an accepted treatment for excessive obesity. We conducted a longitudinal study to assess regional body composition, muscle proteolysis, and energy expenditure before RYGB, and 6 and 12 months after RYGB. Whole-body and regional fat mass (FM) and lean mass (LM) were assessed via dual energy X-ray ab...
Article
Full-text available
While chronic β-Hydroxy β-Methylbutyrate (HMB) supplementation (≥ 2 wk) lowers exercise induced muscle damage, its acute or timing effects have not been examined. The purpose of this study was to investigate the acute and timing effects of oral HMB supplementation on serum creatine kinase (CK), lactate dehydrogenase (LDH), muscle soreness, and maxi...
Article
A major contributing factor to the loss of mobility in elderly people is the gradual and continuous loss of lean body mass. Objectives: To determine whether supplementation of an amino acid cocktail daily for 1 year could improve the age-associated changes in protein turnover and lean body mass in elderly people. Elderly (76+/-1.6 years) women (n=3...