ABSTRACT
Forty-eight 67-day-old male Wistar rats (330+/-5g) were fed ad libitum either with a lipid enriched diet or a standard laboratory chow. Half of each sub-group was submitted to training. Training and difference in diet composition induced nonsignificant changes in body adiposity. Visceral fat (perirenal adipose tissue mass) was correlated with leptin (r=0.35, p=0.02) and insulin (r=0.38, p=0.01). Total body fat mass (measured by DEXA) was correlated with leptin only (r=0.58, p=0.003). Other correlations between perirenal adipose tissue or fat mass and adiponectin or insulin like growth factor 1 were nonsignificant. These results suggest that, in rat like in human, visceral fat development is linked with insulin insensitivity.
Subject(s)
Adipose Tissue/pathology , Insulin-Like Growth Factor I/analysis , Insulin/blood , Intra-Abdominal Fat/pathology , Leptin/blood , Rats, Wistar/physiology , Adiponectin/blood , Adipose Tissue/anatomy & histology , Animals , Body Weight , Dietary Fats/adverse effects , Hyperlipidemias/chemically induced , Hyperlipidemias/pathology , Insulin Resistance , Intra-Abdominal Fat/anatomy & histology , Male , Organ Size , Physical Conditioning, Animal , Rats , Rats, Wistar/anatomy & histology , Rats, Wistar/bloodABSTRACT
OBJECTIVE: The aim of the present study was to investigate the effects of a lipid-enriched diet on body composition and on main regulatory hormones of food intake (insulin, adiponectin, leptin, ghrelin). METHOD: Two groups of 16 rats, 35 days old, weighing 80+/-6 g, were constituted. One group (S) was given a standard diet during 10 weeks and served as control. The second group (L) was given a lipidic-enriched diet (containing: G: 41.5, L: 38.5, P: 20% calorie). Food and water were given "ad libitum". RESULTS: Total food intake, body weight, skeletal area and lean body mass of rats eating lipid-enriched diet were lowered (6694+/-178 vs. 8160+/-184 kcal, P=0.01; 431+/-38 vs. 468+/-25 g, P=0.003; 72.19+/-0.96 vs. 76.07+/-1.31 cm2, P=0.03; 369+/-18 vs. 409+/-23 g, P=0.0006), fat mass difference was not statistically significant (82.5+/-17 vs. 80+/-17 g, P=0.7). Blood ghrelin, adiponectin levels were lowered (1517+/-224 vs. 1915+/-579 pg/ml, P=0.03; 10+/-3 vs. 19+/-3 microg/ml, P=0.003) whereas insulin and leptin were unchanged (1.8+/-1.5 vs. 2.6+/-1.4 ng/ml, P=0.1; 16+/-11 vs. 13+/-10 ng/ml, P=0.4). CONCLUSION: A period of high fat diet in growing rats leads to a hypophagia, resulting in a lower lean body mass development. Some regulatory hormones of food intake did not change, while others significantly decreased, notably ghrelin being possible causal factor of the observed hypophagia linked to high fat diet.