[Show abstract][Hide abstract] ABSTRACT: Functional foods with bioactive properties may help in treat obesity, as they can lead to a decreased risks of inflammatory diseases. The aim of this study was to investigate the effects of chitosan coacervate whey protein on the proinflammatory processes in mice fed with high-fat diet.
Mice were divided into two groups receiving either a normolipidic or high-fat diet; the animals in each of the two diet groups were given a diet supplement of either coacervate (gavage, 36 mg protein/kg of body weight) or tap water for four weeks [groups: normolipidic diet plus water (C); normolipidic diet and coacervate (CC); high-fat diet and water (H); and high-fat diet and coacervate (HC)].
The high-fat diet promoted inflammation, possibly by decreased adiponectin/sum of adipose tissues ratio and increased phosphorylation of NF-kappaB p50. In HC we observed a positive correlation between IL-10 and TNF-alpha in mesenteric adipose tissue, retroperitoneal adipose tissue and liver tissue. We also observed a positive correlation between lipopolisaccharide with IL-10 in the liver tissue.
High-fat diet treatment promoted metabolic alterations and inflammation, and chitosan coacervate whey protein modulated inflammatory milieu.
[Show abstract][Hide abstract] ABSTRACT: Previously, we showed that the intake of trans fatty acids during pregnancy and lactation triggers a pro-inflammatory status in the offspring. On the other hand, prebiotics can alter the intestinal environment, reducing serum lipopolysaccharides (LPS) concentrations. This study evaluated the effect of the oligofructose 10% diet supplementation in the presence or absence of hydrogenated vegetable fat during pregnancy and lactation on the development, endotoxemia and bacterial composition of 21-d-old offspring.
On the first day of pregnancy rats were divided into four groups: control diet (C), control diet supplemented with 10% oligofructose (CF), diet enriched with hydrogenated vegetable fat, rich in TFA (T) or diet enriched with hydrogenated vegetable fat supplemented with 10% oligofructose (TF). Diets were maintained during pregnancy and lactation. At birth, 7th, 14th and 21th, pups were weighed and length was measured. Serum concentrations of LPS and free fatty acids (FFA) were performed by specific kits. Bacterial DNA present in faeces was determined by real-time PCR. Data were expressed as mean +/- standard error of the mean and the statistical analysis was realized by ANOVA two-way and ANOVA for repeated measures. p < 0.05 was considered significant.
We observed that the oligofructose (10%) supplementation during pregnancy and lactation reduced body weight, body weight gain, length and serum FFA in the CF and TF group compared to C and T group respectively, of the 21-day-old offspring, accompanied by an increase in serum LPS and genomic DNA levels of lactobacillus spp. on faeces of the CF group in relation to C group.
In conclusion, dam's diet supplementation with 10% of oligofructose during pregnancy and lactation, independent of addition with hydrogenated vegetable fat, harms the offspring development, alters the bacterial composition and increases the serum concentrations of lipopolysaccharides in 21d-old pups.
Lipids in Health and Disease 02/2014; 13(1):26. · 2.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To investigate possible mechanisms of green tea’s anti-obesity and anti-diabetic effects in the hypothalamus, the central regulator of metabolism, of mice fed with high-fat diet, we analysed proteins of the toll-like receptor 4 pathway and serotoninergic proteins involved in energy homeostasis. Thirty days old male Swiss mice were fed with high-fat diet rich in saturated fat and green tea extract for eight weeks. After that, body weight and mass of fat depots were evaluated. Oral glucose tolerance test was performed three days prior to euthanasia; serum glucose, insulin and adiponectin were measured in fasted mice. Hypothalamic toll-like receptor 4 pathway proteins, serotonin receptors 1B and 2C, and serotonin transporter were analysed by Western blotting or enzyme-linked immunosorbent assay. A second set of animals was used to measure food intake in response to fluoxetine, a selective serotonin reuptake inhibitor. Mice fed with high-fat diet had increased body weight and mass of fat depots, impaired oral glucose tolerance, elevated glucose and insulin, and decreased adiponectin serum levels. Toll-like receptor 4, IκB-α, nuclear factor κB p50, and interleukin-6 were increased by high-fat diet. Concomitant green tea extract treatment ameliorated these parameters. The serotoninergic system remained functional after high-fat diet treatment, despite a few alterations in protein content of serotonin receptors 1B and 2C, and serotonin transporter. In summary, the green tea extract attenuated the deleterious effects of the high-fat diet investigated in this study, partially due to reduced hypothalamic inflammation.
[Show abstract][Hide abstract] ABSTRACT: The low-grade systemic inflammation seen in obesity may affect the actions of some adipose tissue-derived adipokines that are involved in the regulation of vascular function. We sought to verify whether hyperleptinemia may influence the inflammatory and atherogenic responses in obese adolescents undergoing interdisciplinary therapy. Thirty-four obese adolescents underwent interdisciplinary therapy for 1 year. Subjects were considered hyperleptinemic if they had baseline values of leptin above 20 ng/mL for boys and 24 ng/mL for girls. Both groups showed an improvement in body composition and a reduction in carotid intima-media thickness. However, only subjects in the non-hyperleptinemic group showed an increase in adiponectin concentration after therapy. Moreover, leptin concentration was positively correlated with adiponectin and inversely correlated with PAI-1 in this group. Hyperleptinemic state may impair the attenuation of inflammation in obese adolescents undergoing interdisciplinary therapy, particularly by impeding the increase in adiponectin concentration, which is directly involved in vascular protection.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Previously, we demonstrated that trans fatty acid ingestion during pregnancy and lactation caused a pro-inflammatory effect on the newborn. The opposite effect was described for gestational prebiotic intake. In the present study, we examined whether supplementation of the diet of the dams with 10% of oligofructose with or without hydrogenated vegetable fat affected the pro-inflammatory status during pregnancy and lactation on the pups at age 21 days. METHODS: On the first day of pregnancy, rats were divided into four groups, each of which received one of four diets: a control diet (C group), a control diet supplemented with 10% oligofructose (CF group), a diet enriched with hydrogenated vegetable fat containing trans fatty acids (T group) or a diet enriched with hydrogenated vegetable fat containing trans fatty acids supplemented with 10% oligofructose (TF group). The pups were weighed at birth and at 7, 14 and 21 days of life and were euthanized on post-natal day 21. The serum glucose, insulin and adiponectin concentrations were analyzed. The IL-6, IL-10 and TNF-alpha contents of the retroperitoneal white adipose tissue, liver, soleus and extensor digital longus muscles were analyzed by ELISA. The results are presented as the means +/- standard error of the mean. Statistical significance was assessed using two-way ANOVA, followed by Tukey's test and considered significant at p < 0.05 RESULTS: The body weights of the 21-day old pups in the CF and TF groups were significant lower than those of the C (27% and 21%) and T (25% and 19%, respectively) groups. The serum levels of adiponectin in the CF, T and TF groups were lower than in the C group (41%; 34% and 31%, respectively). In the retroperitoneal adipose tissue, the IL-6 content was increased in TF group relative to the C and CF groups (74% for both), and the TNF-alpha content was higher in the T and TF groups than in the C group (62% and 98%, respectively). In the liver, the TNF-alpha (56% and 104%) and IL-10 (52% and 73%) contents were increased in the CF group relative to the C and TF groups. CONCLUSIONS: Supplementation of the diet of the dams with 10% of oligofructose during pregnancy and lactation, independent of supplementation with hydrogenated vegetable fat, adversely affected the development of the offspring and contributed to development of a pro-inflammatory status in the pups on postnatal day 21.
Lipids in Health and Disease 05/2013; 12(1):59. · 2.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Whether leptin targets the hypothalamic serotonergic system to inhibit food intake is not established. We examined the effect of a short-term i.c.v. leptin treatment on serotonin microdialysate levels in rat lateral hypothalamus. Adipose tissue gene expression was also evaluated. Male rats received four daily injections of leptin (5μg) or vehicle (with pair-feeding to leptin-induced intake) and a fifth injection during collection of LH microdialysates. We found that serotonin and 5-HIAA levels were not affected by the leptin pre-treatment, as basal levels were similar between the leptin and the pair-fed group. These levels remained unaltered after the acute leptin injection. For gene expression studies, rats were pre-treated with five daily injections of either leptin (5μg) or vehicle (with either pair-feeding or ad libitum intake). mRNA levels of resistin, adiponectin, lipoprotein lipase, and PPAR-gamma were unaltered by either leptin or pair-feeding. Leptin gene expression was significantly reduced by leptin but not by pair-feeding, in both the retroperitoneal (-74%) and the epididymal (-99%) depots while no differences were observed in the subcutaneous depot. The observations confirmed the absence of an acute stimulatory effect of central leptin on serotonin release in the lateral hypothalamus and showed that the pre-treatment with leptin failed to modify this pattern. This indicates that components of the serotonergic system are probably not directly affected by leptin. Additionally, the central effect of leptin was able to downregulate its own adipose tissue gene expression in a depot-specific manner while other adipokine genes were not affected.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to evaluate the effects of green tea Camellia sinensis extract on proinflammatory molecules and lipolytic protein levels in adipose tissue of diet-induced obese mice. Animals were randomized into four groups: CW (chow diet and water); CG (chow diet and water + green tea extract); HW (high-fat diet and water); HG (high-fat diet and water + green tea extract). The mice were fed ad libitum with chow or high-fat diet and concomitantly supplemented (oral gavage) with 400 mg/kg body weight/day of green tea extract (CG and HG, resp.). The treatments were performed for eight weeks. UPLC showed that in 10 mg/mL green tea extract, there were 15 μg/mg epigallocatechin, 95 μg/mg epigallocatechin gallate, 20.8 μg/mg epicatechin gallate, and 4.9 μg/mg gallocatechin gallate. Green tea administered concomitantly with a high-fat diet increased HSL, ABHD5, and perilipin in mesenteric adipose tissue, and this was associated with reduced body weight and adipose tissue gain. Further, we observed that green tea supplementation reduced inflammatory cytokine TNFα levels, as well as TLR4, MYD88, and TRAF6 proinflammatory signalling. Our results show that green tea increases the lipolytic pathway and reduces adipose tissue, and this may explain the attenuation of low-grade inflammation in obese mice.
Mediators of Inflammation 01/2013; 2013:635470. · 3.88 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Whether PUFA diets affect inflammatory mediators in central and peripheral sites is not clear. We investigated the effect of high-fat PUFA diets on the expression of proteins involved in inflammatory pathways in hypothalamus, muscle, and liver. Male rats were fed for 2 months with either chow or high-fat diets enriched with either soy (n-6 PUFAs) or fish oil (n-3 PUFAs). The fish group had normal body weight, low serum NEFA, reduced hypothalamic levels of TNF- α , IL-6, and TRAF6, and increased levels of IL-10 receptor. In contrast, the soy group had increased body weight and hypothalamic levels of TRAF6 and NF κ Bp65. In muscle, the fish diet reduced TNF- α and IL-6 levels. Both PUFA diets increased muscle IL-10 levels and reduced liver TNF- α and IL-6 levels. The data showed that the high-fat soy diet induced activation of the hypothalamic NF κ B inflammatory pathway, a feature predisposing to feeding and energy expenditure disturbances associated with the development of obesity. On the other hand, the high-fat fish diet improved the central and the peripheral inflammatory profile via reduction of intracellular inflammatory mediators, suggesting a protection against obesity.
[Show abstract][Hide abstract] ABSTRACT: The prevention of obesity and health concerns related to body fat is a major challenge worldwide. The aim of this study was to investigate the role of a medically supervised, multidisciplinary approach, on reduction in the prevalence of obesity related comorbidities, inflammatory profile, and neuroendocrine regulation of energy balance in a sample of obese adolescents. A total of 97 postpuberty obese adolescents were enrolled in this study. Body composition, neuropeptides, and adipokines were analysed. The metabolic syndrome was defined by the International Diabetes Federation (IDF). The abdominal ultrasonography was performed to measure visceral, subcutaneous fat and hepatic steatosis. All measures were performed at baseline and after one year of therapy. The multidisciplinary management promoted the control of obesity reducing body fat mass. The prevalence of metabolic syndrome, asthma, nonalcoholic fatty liver disease (NAFLD), binge eating, and hyperleptinemia was reduced. An improvement in the inflammatory profile was demonstrated by an increase in anti-inflammatory adiponectin and reduction in proinflammatory adipokines, plasminogen activator inhibitor-1, interleukin-6 concentrations, and in the Lep/Adipo ratio. Moreover, a reduction in the AgRP and an increase in the alfa-MSH were noted. The multidisciplinary approach not only reduced obesity but also is efficacious in cardiovascular risk factors, inflammatory profile, and neuroendocrine regulation of energy balance.
International Journal of Endocrinology 01/2013; 2013:541032. · 2.52 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective: To assess the effects of weight loss on adipokines, asthma-related symptoms, exercise-induced bronchospasm (EIB) and lung function, and to evaluate the role of leptin and adiponectin levels on lung function after treatment in obese adolescents. Methods: 84 postpubertal obese adolescents were enrolled and distributed in quartiles according to weight loss (low (<2.5 kg), low to moderate (>2.5 and <8 kg), moderate (<8 and <14 kg) and massive (<14 kg)). Body composition was measured by plethysmography, and visceral and subcutaneous fat were detected by ultrasound. Serum levels of adiponectin and leptin were analyzed. Lung function, asthma and EIB were evaluated according to the American Thoracic Society criteria. Patients were submitted to 1 year of interdisciplinary intervention consisting of physiotherapy, medical, nutritional, exercise, and psychological therapy. Results: After treatment the moderate and massive weight loss promoted an increase in adiponectin and adiponectin/leptin (A/L) ratio as well as a decrease in leptin levels and a reduction in EIB frequency and asthma-related symptoms. Furthermore, the reduction in leptin levels was a predictor factor to improvement in lung function. Conclusion: Interdisciplinary therapy was able to decrease EIB and asthma-related symptoms and to improve pro/anti-inflammatory adipokines. Additionally, the leptin concentration was a predictor factor to explain changes in lung function.
[Show abstract][Hide abstract] ABSTRACT: The purpose of the present study was to assess the dietary fat intake, glucose, insulin, Homeostasis model assessment for insulin resistance HOMA-IR, and endotoxin levels and correlate them with adipokine serum concentrations in obese adolescents who had been admitted to long-term interdisciplinary weight-loss therapy.
The present study was a longitudinal clinical intervention of interdisciplinary therapy. Adolescents (n = 18, aged 15-19 y) with a body mass index > 95th percentile were admitted and evaluated at baseline and again after 1 year of interdisciplinary therapy. We collected blood samples, and IL-6, adiponectin, and endotoxin concentrations were measured by ELISA. Food intake was measured using 3-day diet records. In addition, we assessed glucose and insulin levels as well as the homeostasis model assessment for insulin resistance (HOMA-IR).
The most important finding from the present investigation was that the long-term interdisciplinary lifestyle therapy decreased dietary fat intake and endotoxin levels and improved HOMA-IR. We observed positive correlations between dietary fat intake and endotoxin levels, insulin levels, and the HOMA-IR. In addition, endotoxin levels showed positive correlations with IL-6 levels, insulin levels and the HOMA-IR. Interestingly, we observed a negative correlation between serum adiponectin and both dietary fat intake and endotoxin levels.
The present results indicate an association between dietary fat intake and endotoxin level, which was highly correlated with a decreased pro-inflammatory state and an improvement in HOMA-IR. In addition, this benefits effect may be associated with an increased adiponectin level, which suggests that the interdisciplinary therapy was effective in improving inflammatory pathways.
[Show abstract][Hide abstract] ABSTRACT: To clarify the effects of natural dietary components on the metabolic consequences of obesity, we examined the effects of yerba mate extract Ilex paraguariensis on both central and peripheral inflammatory effects of diet-induced obesity and correlated the hypothalamic tumor necrosis factor (TNF)-α level with adipose depot weight. Wistar rats were divided into four groups: a control group (CTL) fed with chow diet, a second group fed with chow diet plus yerba mate extract (CTL+E), a third group fed with a high-fat diet rich in saturated fatty acids (HFD) and a fourth group fed with HFD plus yerba mate extract (HFD+E). Enzyme-linked immunosorbent assay, Western blotting, colorimetric method and treatment by gavage were utilized as materials and methods. The HFD groups showed a significant increase in food intake (kcal), body weight, adipose tissue and leptin level in comparison to CTL and CTL+E. HFD leads to increase of both central and peripheral inflammatory effects, and deregulation of insulin pathway. In addition, yerba mate extract intake blunted the proinflammatory effects of diet-induced obesity in rats by reducing the phosphorylation of hypothalamic IKK and NFκBp65 expression and increasing the phosphorylation of IκBα, the expression of adiponectin receptor-1 and consequently the amount of IRS-2. Moreover, the increase in interleukin (IL)-6 levels in the liver and muscle and of the IL-10/TNF-α ratio in groups that received yerba mate extract showed the anti-inflammatory effects of this natural substance. Taken together, our data suggest that the use of yerba mate extract may be useful for reducing low-grade obesity-associated inflammation.
The Journal of nutritional biochemistry 07/2012; · 4.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Aging and physical inactivity are 2 factors that favour the development of cardiovascular disease, metabolic syndrome, obesity, and diabetes. In contrast, adopting a habitual moderate exercise routine may be a nonpharmacological treatment alternative for neuroendocrine aging disorders. We aimed to assess the effects of moderate exercise training on the metabolic profiles of elderly people with sedentary lifestyles. Fourteen sedentary, healthy, elderly male volunteers participated in a moderate training regimen for 60 min/day, 3 days/week for 24 weeks at a work rate equivalent to their ventilatory aerobic threshold. The environment was maintained at a temperature of 23±2°C, with a humidity of 60±5%. Blood samples for analysis were collected at 3 intervals: at baseline (1 week before training began), and 3 and 6 months after training. The training promoted increased aerobic capacity (relative VO2, and time and velocity to VO2max; (p<0.05)) and reduced serum α-MSH (p<0.05) after 3 months of training when compared with the baseline data. In addition, serum thyroid hormone (T3 and T4) was reduced after 6 months of training compared with baseline levels. Our results demonstrate that a moderate exercise training protocol improves the metabolic profile of older people, and metabolic adaptation is dependent on time.
Hormone and Metabolic Research 06/2012; · 2.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The hypothalamus plays a pivotal role in numerous mechanisms highly relevant to the maintenance of body homeostasis, such as the control of food intake and energy expenditure. Impairment of these mechanisms has been associated with the metabolic disturbances involved in the pathogenesis of obesity. Since rodent species constitute important models for metabolism studies and the rat hypothalamus is poorly characterized by proteomic strategies, we performed experiments aimed at constructing a two-dimensional gel electrophoresis (2-DE) profile of rat hypothalamus proteins.
As a first step, we established the best conditions for tissue collection and protein extraction, quantification and separation. The extraction buffer composition selected for proteome characterization of rat hypothalamus was urea 7 M, thiourea 2 M, CHAPS 4%, Triton X-100 0.5%, followed by a precipitation step with chloroform/methanol. Two-dimensional (2-D) gels of hypothalamic extracts from four-month-old rats were analyzed; the protein spots were digested and identified by using tandem mass spectrometry and database query using the protein search engine MASCOT. Eighty-six hypothalamic proteins were identified, the majority of which were classified as participating in metabolic processes, consistent with the finding of a large number of proteins with catalytic activity. Genes encoding proteins identified in this study have been related to obesity development.
The present results indicate that the 2-DE technique will be useful for nutritional studies focusing on hypothalamic proteins. The data presented herein will serve as a reference database for studies testing the effects of dietary manipulations on hypothalamic proteome. We trust that these experiments will lead to important knowledge on protein targets of nutritional variables potentially able to affect the complex central nervous system control of energy homeostasis.
[Show abstract][Hide abstract] ABSTRACT: To investigate the role of pro- and anti-inflammatory adipokines in the bone metabolism of non-alcoholic fatty liver disease (NAFLD) obese adolescents as well as the effects of long-term interdisciplinary therapy on metabolic-related risk factors. Forty post-puberty obese adolescents were randomly assigned into two groups: (1) NAFLD group and (2) non-NAFLD group (diagnosis by ultrasonography) and submitted to a weight loss therapy. Body composition was analyzed by air displacement plethysmography, bone mineral density (BMD) and content by dual-energy X-ray absorptiometry, blood samples were collected to measure lipid profile, hepatic enzymes, and adipokines. Leptin and adiponectin concentrations were measured by ELISA. A decrease in total body mass, BMI, body fat, visceral and subcutaneous fat, insulin concentration, HOMA-IR, total cholesterol and an increase in lean body mass were observed in both groups after therapy. It was found positive correlation between the Δ BMD and the Δ fat mass (%) (r = 0.31, P = 0.01) and negative correlations between Δ BMC with Δ HOMA-IR (r = -0.34, P = 0.02) and Δ HOMA-IR with Δ leptin (r = -0.34, P = 0.02). In addition, increased levels of adiponectin and reduction in leptin concentrations were observed in NAFLD group. In the simple regression analysis, the HOMA-IR was an independent predictor changes in BMC in total obese adolescents and in the non-NAFLD group. One year of interdisciplinary weight loss therapy for obese adolescents with or without NAFLD, could regulate bone mineral metabolism as result of an increased BMC and improved inflammatory state.
[Show abstract][Hide abstract] ABSTRACT: The simultaneous rise in the prevalence of asthma and obesity in the world, have demonstrated the importance of the development of treatment strategies. The purpose of this study was to evaluate the short- and long-term results of interdisciplinary therapy on inflammatory biomarkers and lung function in asthmatics obese adolescents.
Seventy-six post-pubertal obese adolescents were recruited, including 50 non-asthmatics [body mass index (BMI), 36 ± 5 kg/m(2) ) and 26 asthmatics (BMI, 39 ± 4 kg/m(2) ). Body composition was measured by plethysmography, and visceral fat was analyzed by ultrasound. Serum levels of adiponectin, leptin, and C-reactive protein (CRP) were analyzed. Asthma and lung function were evaluated according to the American Thoracic Society criteria. Patients were submitted to 1-year weight loss interdisciplinary intervention consisting of medical, nutritional, exercise, and psychological therapy.
After interdisciplinary intervention, the lung function and pro/anti-inflammatory adipokines improved significantly in both groups. Most importantly, there was an increase in adiponectin [4 (1.86-12.9) to 5.1 (2.48-16)], a reduction in CRP [2,073 (385-9,174) to 1,538 (205-7,083)] and leptin concentrations [59 (29-69) to 33 (9-49)] in the asthmatics patients. Furthermore, it was observed a reduction in asthma severity after treatment. In addition, Δ adiponectin was an independent factor to improve lung function after therapy in both groups.
Interdisciplinary therapy resulted in beneficial changes in inflammatory biomarkers profile and lung function in asthmatic and non-asthmatic obese adolescents. Additionally, for the first time we showed that change in adiponectin level was an independent predictor to improve lung function in Brazilian obese adolescents.
[Show abstract][Hide abstract] ABSTRACT: Adiponectin and interleukin 10 (IL-10) are adipokines that are predominantly secreted by differentiated adipocytes and are involved in energy homeostasis, insulin sensitivity, and the anti-inflammatory response. These two adipokines are reduced in obese subjects, which favors increased activation of nuclear factor kappa B (NF-κB) and leads to elevation of pro-inflammatory adipokines. However, the effects of adiponectin and IL-10 on NF-κB DNA binding activity (NF-κBp50 and NF-κBp65) and proteins involved with the toll-like receptor (TLR-2 and TLR-4) pathway, such as MYD88 and TRAF6 expression, in lipopolysaccharide-treated 3T3-L1 adipocytes are unknown. Stimulation of lipopolysaccharide-treated 3T3-L1 adipocytes for 24h elevated IL-6 levels; activated the NF-κB pathway cascade; increased protein expression of IL-6R, TLR-4, MYD88, and TRAF6; and increased the nuclear activity of NF-κB (p50 and p65) DNA binding. Adiponectin and IL-10 inhibited the elevation of IL-6 levels and activated NF-κB (p50 and p65) DNA binding. Taken together, the present results provide evidence that adiponectin and IL-10 have an important role in the anti-inflammatory response in adipocytes. In addition, inhibition of NF-κB signaling pathways may be an excellent strategy for the treatment of inflammation in obese individuals.
[Show abstract][Hide abstract] ABSTRACT: We have previously shown that either the continuous intake of a palatable hyperlipidic diet (H) or the alternation of chow (C) and an H diet (CH regimen) induced obesity in rats. Here, we investigated whether the time of the start and duration of these feeding regimens are relevant and whether they affect brain glucose metabolism.
Male Wistar rats received C, H, or CH diets during various periods of their life spans: days 30-60, days 30-90, or days 60-90. Experiments were performed the 60th or the 90th day of life. Rats were killed by decapitation. The glucose, insulin, leptin plasma concentration, and lipid content of the carcasses were determined. The brain was sliced and incubated with or without insulin for the analysis of glucose uptake, oxidation, and the conversion of [1-14C]-glucose to lipids.
The relative carcass lipid content increased in all of the H and CH groups, and the H30-60 and H30-90 groups had the highest levels. Groups H30-60, H30-90, CH30-60, and CH30-90 exhibited a higher serum glucose level. Serum leptin increased in all H groups and in the CH60-90 and CH30-90 groups. Serum insulin was elevated in the H30-60, H60-90, CH60-90, CH30-90 groups. Basal brain glucose consumption and hypothalamic insulin receptor density were lower only in the CH30-60 group. The rate of brain lipogenesis was increased in the H30-90 and CH30-90 groups.
These findings indicate that both H and CH diet regimens increased body adiposity independent treatment and the age at which treatment was started, whereas these diets caused hyperglycemia and affected brain metabolism when started at an early age.
Lipids in Health and Disease 09/2011; 10:168. · 2.31 Impact Factor