Effects on Fat Distribution by Food Restriction in Zucker Diabetic Fatty Rats
T. Ohta *
Japan Tobacco Inc., Central Pharmaceutical Research Institute, Osaka, Japan and Laboratory of Animal Genetics, Graduate School of Science and Technology, Niigata University, Niigata, Japan.
Y. Ishii
Japan Tobacco Inc., Central Pharmaceutical Research Institute, Osaka, Japan.
M. Shinohara
CLEA Japan Inc., Planning and Development Section, Tokyo, Japan.
H. Yamashiro
Laboratory of Animal Genetics, Graduate School of Science and Technology, Niigata University, Niigata, Japan.
T. Yamada
Laboratory of Animal Genetics, Graduate School of Science and Technology, Niigata University, Niigata, Japan.
*Author to whom correspondence should be addressed.
Abstract
Aim: Zucker diabetic fatty (ZDF) rat is a type 2 diabetic model with hyperphagia, obesity, and the overt fat storage. The present study investigated effects of food restriction for 15 weeks on the fat distribution in ZDF rats.
Methods: ZDF rats were pair-fed with Zucker Lean (ZL) rats from 9 to 24 weeks of age. Body weight and blood chemistry parameters, such as glucose, insulin, triglyceride, total cholesterol and non-esterified fatty acid, were measured every two weeks. The visceral and subcutaneous fat weights were measured at 24 weeks of age by computed tomography (CT) analysis, and the total fat weight and the ratio of visceral fat weight to subcutaneous fat weight (V/S ratio) were determined.
Results: The ZDF rats showed obesity, hyperglycemia, hyperinsulinemia, and hyperlipidemia as compared with the ZL rats. Pair-fed ZDF rats showed a temporary decrease in body weight and a suppression of hyperglycemia, but the blood insulin and lipid levels increased. Total fat weight was about 2.4 times higher in the ZDF rats than the ZL rats. The total fat weight in Pair-fed ZDF rats was increased by 56%, but the V/S ratio was decreased by 38% at 24 weeks of age.
Conclusion: The change of fat distribution by dietary restriction may be related to the improvement of glucose and lipid metabolic disorders in diabetes mellitus with obesity.
Keywords: Food restriction, fat distribution, visceral fat, Zucker diabetic fatty rat