Regional variations in metabolic responses of white adipose tissue to food restriction

Abstract

The effects of food restriction (limited access to food for 2 h/day for 10 days) on lipoprotein lipase (LPL) activities and rates of fatty acid synthesis and glucose utilization in vivo in two superficial (interscapular and subcutaneous) and three deep abdominal white adipose tissue depots (parametrial, perirenal, and mesenteric) of adult female Wistar rats were examined before and at 2 h after a standard laboratory diet meal (5 g). Fasting LPL activities in perirenal (1.6-fold), mesenteric (5.9-fold), and subcutaneous (2.7-fold) adipose tissue, when expressed per unit of delipidated tissue, were increased in response to food restriction. This effect was retained (but not enhanced) after the meal. In contrast, muscle LPL activities were either unchanged or suppressed by food restriction. Stimulation of adipose tissue fatty acid synthesis and glucose utilization evoked by feeding in control rats was greatly enhanced by prior food restriction. There was no relationship between anatomical location and presence or absence of the response of adipose tissue LPL activity to food restriction, but the effect of food restriction to enhance the responses of fatty acid synthesis and glucose utilization to a meal was more marked in perirenal and parametrial adipose tissue than in the more superficial depots. The results thus demonstrate regional specificity in the response of adipose tissue functions to food restriction.