Effect of insulin on adipocyte lipolysis in exercise-trained rats

2935-2939,1993.-The effect of exercise training on the antili-polytic action of insulin was studied in rat adipocytes. Exercise training enhanced lipolysis induced by norepinephrine. Insulin dose dependently inhibited norepinephrine- (1 PM) stimulated lipolysis in both groups. Its inhibition rate was significantly greater in the trained than in the control group. Thus, exercise training enhanced the antilipolytic action of insulin. In the con-trol group, insulin (1,000 pU/ml) reduced the displacement rate of [3H]CGP-12177 binding to adipocytes by low concentrations of (-)-norepinephrine. The slope factor without insulin was 0.76, whereas that with insulin was 0.95. In the trained group, insulin did not affect the competition binding of (-)-norepi-nephrine for [3H]CGP-12177. The displacement rate of [3H]CGP-12177 binding from adipocytes by low concentrations of (-)-norepinephrine was significantly greater in the traine