scholarly journals Regulation of plasma leptin in mice: influence of age, high-fat diet, and fasting

1997 ◽  
Vol 273 (1) ◽  
pp. R113-R120 ◽  
Author(s):  
B. Ahren ◽  
S. Mansson ◽  
R. L. Gingerich ◽  
P. J. Havel
Keyword(s):  
Body Weight ◽  
Dietary Fat ◽  
High Fat Diet ◽  
Plasma Insulin ◽  
Plasma Concentrations ◽  
Age Groups ◽  
Fat Content ◽  
High Fat ◽  
Background Strain ◽  
Plasma Leptin

Mechanisms regulating circulating leptin are incompletely understood. We developed a radioimmunoassay for mouse leptin to examine the influence of age, dietary fat content, and fasting on plasma concentrations of leptin in the background strain for the ob/ob mouse, the C57BL/6J mouse. Plasma leptin increased with age [5.3 +/- 0.6 ng/ml at 2 mo (n = 23) vs. 14.2 +/- 1.6 ng/ml at 11 mo (n = 15), P < 0.001]. Across all age groups (2-11 mo, n = 160), log plasma leptin correlated with body weight (r = 0.68, P < 0.0001), plasma insulin (r = 0.38, P < 0.001), and amount of intra-abdominal fat (r = 0.90, P < 0.001), as revealed by magnetic resonance imaging. Plasma leptin was increased by a high-fat diet (58% fat for 10 mo) and reduced by fasting for 48 h. The reduction of plasma leptin was correlated with the reduction of plasma insulin (r = 0.43, P = 0.012) but not with the initial body weight or the change in body weight. Moreover, the reduction in plasma leptin by fasting was impaired by high-fat diet. Thus plasma leptin in C57BL/6J mice 1) increases with age or a high-fat diet; 2) correlates with body weight, fat content, and plasma insulin; and 3) is reduced during fasting by an action inhibited by high-fat diet and related to changes of plasma insulin.

scholarly journals Macronutrient balances and obesity: the role of diet and physical activity

1999 ◽  
Vol 2 (3a) ◽  
pp. 341-347 ◽  
Author(s):  
Arne Astrup
Keyword(s):  
Physical Activity ◽  
Weight Loss ◽  
Body Weight ◽  
Weight Gain ◽  
Physical Fitness ◽  
Dietary Fat ◽  
High Fat Diet ◽  
Fat Oxidation ◽  
Fat Content ◽  
High Fat

AbstractObservational cross-sectional and longitudinal studies suggest that a high fat diet and physical inactivity are independent risk factors for weight gain and obesity. Mechanistic and intervention studies support that fat possesses a lower satiating power than carbohydrate and protein, and a diet low in fat therefore decreases energy intake. The effect of dietary fat on energy balance is enhanced in susceptible subjects, particularly in sedentary individuals with a genetic predisposition to obesity who consume a high fat diet.Dietary carbohydrate promotes its own oxidation by an insulin-mediated stimulation of glucose oxidation. In contrast, high fat meals do not increase fat oxidation acutely. A sedentary life-style and low physical fitness cause a low muscular fat oxidation capacity, and the consumption of a high fat diet by these individuals promotes fat storage in a synergistic fashion.Ad libitum low fat diets cause weight loss proportional to pre-treatment body weight in a dose-dependent way, i.e. weight loss is correlated positively to the reduction in dietary fat content. Increased physical activity prevents relapse after weight loss and studies have shown that those who keep up a higher level of physical activity are more successful in maintaining the reduced body weight. In conclusion, important interactions exist between genetic make up, dietary fat and physical fitness, so that a low fitness level and susceptible genes reduce muscular fat oxidation capacity which may decrease the tolerance of dietary fat. Increasing daily physical activity and reducing dietary fat content may be more effective when combined than when separate in preventing weight gain and obesity.

Impact of graded maternal dietary fat content on offspring susceptibility to high‐fat diet in mice

Obesity ◽  
2021 ◽  
Vol 29 (12) ◽  
pp. 2055-2067
Author(s):  
Yi Huang ◽  
Jazmin Osorio Mendoza ◽  
Min Li ◽  
Zengguang Jin ◽  
Baoguo Li ◽  
...  
Keyword(s):  
Dietary Fat ◽  
High Fat Diet ◽  
Fat Content ◽  
High Fat

Abstract 17361: How Leptin Harms the Heart in High Fat Diet-Induced Obesity

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Maria Pini
Keyword(s):  
Body Weight ◽  
Mass Loss ◽  
Fat Mass ◽  
High Fat Diet ◽  
Cardiac Fibroblasts ◽  
High Fat ◽  
Wide Range ◽  
Plasma Leptin ◽  
Fat Mass Loss

Introduction: Sedentary lifestyle and excessive calorie intake are risk factors for CVD. We have demonstrated the cardioprotective effect of exercise in aged mice and the critical role of visceral adiposity and its profibrotic secretome in increasing cardiovascular risks in obesity and aging. The association between exercise, lowered plasma leptin and reduced inflammatory leukocytes has been recently shown in patients with atherosclerosis. It remains unclear whether elevated plasma leptin can preserve or alter cardiovascular function in obesity. Methods: We analyzed the effect of high fat diet (HFD) in C57BL/6J male mice on the heart in terms of function, structure, histology and key molecular markers. Two interventions were used: 1) active fat mass loss via exercise (daily swimming) during HFD; 2) passive fat mass loss via surgical removal of the visceral adipose tissue (VAT lipectomy) followed by HFD. Results: HFD increased body weight and adiposity, leading to higher plasma leptin, glucose and insulin levels, compared to control diet (CD) mice. HFD impaired left ventricle (LV) structure (hypertrophy, interstitial fibrosis) and cardiac function (echocardiography, in vivo hemodynamics). Atria of HFD mice had enhanced pro-inflammatory protein production. Exercise reduced circulating leptin levels in HFD mice by 50%, in line with fat mass loss. In contrast, lipectomy reduced visceral fat mass, but body weight, adiposity and plasma leptin did not change. Both exercise and VAT lipectomy improved cardiac contractility, reversed collagen deposition and oxidative stress in HFD mice. Both interventions downregulated LV pro-inflammatory markers. We proved the role of leptin in cardiac remodeling in vitro by incubating primary cardiac fibroblasts with hyperleptinemic plasma from HFD mice. Remarkably, plasma from HFD-EX (exercise) suppressed the fibro-proliferative and pro-inflammatory responses of cardiac fibroblasts. Conclusions: Leptin directly contribute to cardiac fibrosis in obesity via activation and proliferation of cardiac fibroblasts. Understanding how leptin signals to the heart might have implications in a wide range of CVD, potentially helping early stratification and personalized care.

scholarly journals The Main and Interactive Effects of Fat and Sodium Contents of the Diet on Characteristics of Metabolic Syndrome in Male Wistar Rats (P08-038-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Alireza Jahan-Mihan ◽  
Kea Schwarz ◽  
Leila Nynia ◽  
Tatyana Kimble
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
High Fat Diet ◽  
Sodium Content ◽  
Fat Content ◽  
High Fat ◽  
High Sodium ◽  
Sodium Diet ◽  
Male Wistar Rats ◽  
High Sodium Diet

Abstract Objectives The objective of this study was to investigate the main and interactive effects of fat and sodium content of the diet on food intake, body weight and composition, glucose metabolism and blood pressure in male Wistar rats. Methods Male Wistar Rats (n = 48, initial body weight: 115.30 ± 1.73 g) were allocated into 4 groups (n = 12/group) and received one of the following diets: Normal sodium normal fat (NSNF), normal sodium high fat (NSHF), high sodium normal fat (HSNF), high sodium high fat (HSHF) diet for 12 weeks. Body weight (BW) and food intake (FI) were measured weekly. Short-term food intake (1, 2 and 12 hours food intake after 12 hours fasting) was measured at week 6. Body composition and organs’ weight were measured at week 12. Systolic (SBP) and diastolic (DBP) blood pressure, pulse and fasting blood glucose (FBG) were measured and oral glucose tolerance test (OGTT) was conducted at weeks 1, 4, 8 and 12. Results Regardless of sodium content, a greater FI (both gram and cal) was observed in rats fed normal fat diet compared with those fed high fat diet. Consistently, FI (g) at 1, 2 and 12 hours was higher in rats fed a normal fat diet. However, no difference in calorie intake was observed at any time point. Higher BW and fat (%) was observed in high fat diet groups. Moreover, greater kidneys’ weights was observed in high sodium diet groups. Fasting blood glucose was higher in rats fed a normal sodium diet compared with those fed a high sodium diet while the tAUC glucose response to glucose preload was higher in rats fed a high fat diet compared with those fed a normal fat diet which is consistent with higher body weight in high fat diet groups. Regardless of fat content of the diet, pulse was higher in rats fed a high sodium diet compared with those fed a normal sodium diet. No effect of either dietary sodium or fat content of the diet on SBP or DBP was observed. Conclusions Fat but not sodium content of the diet is a determining factor in regulation of FI and BW. Moreover, both fat and sodium content of the diet influence the glucose metabolism potentially through different mechanisms. While pulse is influenced by sodium content, the results of this study do not support the effect of sodium or fat content of the diet on either SBP or DBP. Funding Sources UNF, Brooks College of Health internal grant.

Deficits in gastrointestinal responses controlling food intake and body weight

2010 ◽  
Vol 299 (6) ◽  
pp. R1423-R1439 ◽  
Author(s):  
Mihai Covasa
Keyword(s):  
Body Weight ◽  
Adipose Tissue ◽  
Gastrointestinal Tract ◽  
Energy Metabolism ◽  
Dietary Fat ◽  
High Fat Diet ◽  
Dietary Fats ◽  
Hormone Release ◽  
High Fat ◽  
Chronic Ingestion

The gastrointestinal tract serves as a portal sensing incoming nutrients and relays mechanical and chemosensory signals of a meal to higher brain centers. Prolonged consumption of dietary fat causes adaptive changes within the alimentary, metabolic, and humoral systems that promote a more efficient process for energy metabolism from this rich source, leading to storage of energy in the form of adipose tissue. Furthermore, prolonged ingestion of dietary fats exerts profound effects on responses to signals involved in termination of a meal. This article reviews the effects of ingested fat on gastrointestinal motility, hormone release, and neuronal substrates. It focuses on changes in sensitivity to satiation signals resulting from chronic ingestion of high-fat diet, which may lead to disordered appetite and dysregulation of body weight.

scholarly journals It’s the fiber, not the fat: Significant effects of dietary challenge on the gut microbiome

2019 ◽  
Author(s):  
Kathleen E. Morrison ◽  
Eldin Jašarević ◽  
Christopher D. Howard ◽  
Tracy L. Bale
Keyword(s):  
Body Weight ◽  
Gut Microbiota ◽  
Dietary Fat ◽  
Gut Microbiome ◽  
High Fat Diet ◽  
Body Weight Gain ◽  
Chow Diet ◽  
Soluble Fiber ◽  
High Fat ◽  
The Impact

AbstractBackgroundDietary effects on the gut microbiome has been shown to play a key role in the pathophysiology of behavioral dysregulation, inflammatory disorders, metabolic syndrome, and obesity. Often overlooked is that experimental diets vary significantly in the proportion and source of dietary fiber. Commonly, treatment comparisons are made between animals that are fed refined diets that lack soluble fiber and animals fed vivarium-provided chow diet that contain a rich source of soluble fiber. Despite the well-established role of soluble fiber on metabolism, immunity, and behavior via the gut microbiome, the extent to which measured outcomes may be driven by differences in dietary fiber is unclear. Further, the significant impact of sex and age in response to dietary challenge is likely important and should also be considered.ResultsWe compared the impact of transitioning young and aged male and female mice from a chow diet to a refined low soluble fiber diet on body weight and gut microbiota. Then, to determine the contribution of dietary fat, we examined the impact of transitioning a subset of animals from refined low fat to refined high fat diet. Serial tracking of body weights revealed that consumption of low fat or high fat refined diet increased body weight in young and aged adult male mice. Young adult females showed resistance to body weight gain, while high fat diet-fed aged females had significant body weight gain. Transition from a chow diet to low soluble fiber refined diet accounted for most of the variance in community structure and composition across all groups. This dietary transition was characterized by a loss of taxa within the phylum Bacteroidetes and a concurrent bloom of Clostridia and Proteobacteria in a sex- and age-specific manner. Most notably, no changes to gut microbiota community structure and composition were observed between mice consuming either low- or high-fat diet, suggesting that transition to the refined diet that lacks soluble fiber is the primary driver of gut microbiota alterations, with limited additional impact of dietary fat on gut microbiota.ConclusionCollectively, our results show that the choice of control diet has a significant impact on outcomes and interpretation related to body weight and gut microbiota. These data also have broad implications for rodent studies that draw comparisons between refined high fat diets and chow diets to examine dietary fat effects on metabolic, immune, behavioral, and neurobiological outcomes.

scholarly journals Programming With Varying Dietary Fat Content Alters Cardiac Insulin Receptor, Glut4 and FoxO1 Immunoreactivity in Neonatal Rats, Whereas High Fat Programming Alters Cebpa Gene Expression in Neonatal Female Rats

2022 ◽  
Vol 12 ◽  
Author(s):  
Annelene Govindsamy ◽  
Samira Ghoor ◽  
Marlon E. Cerf
Keyword(s):  
Gene Expression ◽  
Insulin Receptor ◽  
Insulin Signaling ◽  
Dietary Fat ◽  
High Fat Diet ◽  
Female Offspring ◽  
Fat Content ◽  
Neonatal Rats ◽  
Cardiac Physiology ◽  
High Fat

Fetal programming refers to an intrauterine stimulus or insult that shapes growth, development and health outcomes. Dependent on the quality and quantity, dietary fats can be beneficial or detrimental for the growth of the fetus and can alter insulin signaling by regulating the expression of key factors. The effects of varying dietary fat content on the expression profiles of factors in the neonatal female and male rat heart were investigated and analyzed in control (10% fat), 20F (20% fat), 30F (30% fat) and 40F (40% fat which was a high fat diet used to induce high fat programming) neonatal rats. The whole neonatal heart was immunostained for insulin receptor, glucose transporter 4 (Glut4) and forkhead box protein 1 (FoxO1), followed by image analysis. The expression of 84 genes, commonly associated with the insulin signaling pathway, were then examined in 40F female and 40F male offspring. Maintenance on diets, varying in fat content during fetal life, altered the expression of cardiac factors, with changes induced from 20% fat in female neonates, but from 30% fat in male neonates. Further, CCAAT/enhancer-binding protein alpha (Cebpa) was upregulated in 40F female neonates. There was, however, differential expression of several insulin signaling genes in 40F (high fat programmed) offspring, with some tending to significance but most differences were in fold changes (≥1.5 fold). The increased immunoreactivity for insulin receptor, Glut4 and FoxO1 in 20F female and 30F male neonatal rats may reflect a compensatory response to programming to maintain cardiac physiology. Cebpa was upregulated in female offspring maintained on a high fat diet, with fold increases in other insulin signaling genes viz. Aebp1, Cfd (adipsin), Adra1d, Prkcg, Igfbp, Retn (resistin) and Ucp1. In female offspring maintained on a high fat diet, increased Cebpa gene expression (concomitant with fold increases in other insulin signaling genes) may reflect cardiac stress and an adaptative response to cardiac inflammation, stress and/or injury, after high fat programming. Diet and the sex are determinants of cardiac physiology and pathophysiology, reflecting divergent mechanisms that are sex-specific.

scholarly journals Cardioprotective Effects of Metformin and Vildagliptin in Adult Rats with Insulin Resistance Induced by a High-Fat Diet

Endocrinology ◽  
2012 ◽  
Vol 153 (8) ◽  
pp. 3878-3885 ◽  
Author(s):  
Nattayaporn Apaijai ◽  
Hiranya Pintana ◽  
Siriporn C. Chattipakorn ◽  
Nipon Chattipakorn
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Body Weight ◽  
Mitochondrial Dysfunction ◽  
Cardiac Dysfunction ◽  
High Fat Diet ◽  
Plasma Insulin ◽  
High Fat ◽  
Antidiabetic Drug ◽  
Sympathovagal Imbalance

Insulin resistance has been shown to be associated with cardiac sympathovagal imbalance, myocardial dysfunction, and cardiac mitochondrial dysfunction. Whereas metformin is a widely used antidiabetic drug to improve insulin resistance, vildagliptin is a novel oral antidiabetic drug in a group of dipeptidyl peptidase-4 inhibitors in which its cardiac effect is unclear. This study aimed to determine the cardiovascular effects of metformin and vildagliptin in rats with insulin resistance induced by high-fat diet. Male Wistar rats were fed with either a normal diet or high-fat diet (n =24 each) for 12 wk. Rats in each group were divided into three subgroups to receive the vehicle, metformin (30 mg/kg, twice daily), or vildagliptin (3 mg/kg, once daily) for another 21 d. Heart rate variability (HRV), cardiac function, and cardiac mitochondrial function were determined and compared among these treatment groups. Rats exposed to a high-fat diet developed increased body weight, visceral fat, plasma insulin, cholesterol, oxidative stress, depressed HRV, and cardiac mitochondrial dysfunction. Metformin and vildagliptin did not alter body weight and plasma glucose levels but decreased the plasma insulin, total cholesterol, and oxidative stress levels. Although both metformin and vildagliptin attenuated the depressed HRV, cardiac dysfunction, and cardiac mitochondrial dysfunction, vildagliptin was more effective in this prevention. Furthermore, only vildagliptin prevented cardiac mitochondrial membrane depolarization caused by consumption of a high-fat diet. We concluded that vildagliptin is more effective in preventing cardiac sympathovagal imbalance and cardiac dysfunction, as well as cardiac mitochondrial dysfunction, than metformin in rats with insulin resistance induced by high-fat diet.

Intracerebroventricular infusions of 3-OHB and insulin in a rat model of dietary obesity

1988 ◽  
Vol 255 (6) ◽  
pp. R974-R981 ◽  
Author(s):  
K. Arase ◽  
J. S. Fisler ◽  
N. S. Shargill ◽  
D. A. York ◽  
G. A. Bray
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Dietary Fat ◽  
High Fat Diet ◽  
Third Ventricle ◽  
Sprague Dawley ◽  
High Fat ◽  
Low Fat ◽  
The Third ◽  
Intracerebroventricular Infusion

We examined the effect of dietary fat on the response to 3-hydroxybutyrate (3-OHB) and insulin infused chronically into the third ventricle in three strains of rats with differing susceptibility to obesity induced by a high-fat diet: Osborne-Mendel rats are most susceptible; Sprague-Dawley-rats are intermediate; and S 5B/Pl rats are most resistant. Ten days after implantation of cannulas into the third ventricle, rats were fed either a low-fat diet or a high-fat diet for 14 days. On day 7, osmotic minipumps were attached to the ventricular cannulas. 3-OHB infusions (3.6 mumol/24 h) reduced food intake and body weight in Sprague-Dawley and Osborne-Mendel rats eating either diet. The dietary fat-resistant S 5B/Pl rats did not respond to the intracerebroventricular infusion of 3-OHB. The infusion of insulin (10 mU/24 h) lowered food intake and body weight in animals eating the low-fat (high-carbohydrate) diet but not in animals eating the high-fat diet. Diet profoundly affects the response to intracerebroventricular infusions of insulin but is without effect on the response to 3-OHB.

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