A STUDY OF LIPOLYTIC ACTIVITY ON EPIDIDYMAL ADIPOSE TISSUE DURING EXERCISE

Abstract

34 male rats (13 weeks old) were used in this experiment. 11 rats were at rest and 23 rats were loaded to run on a treadmill with 2 degree slope at a speed of 25m/min. Relation between quantities of blood substances (plasma glycerol, blood lactate and plasma free fatty acids ; FFA) and lipolytic activity of epididymal adipose tissue was studied to clarify a mechanism of lipolysis of the adipose tissue in the exercise.
1) Plasma FFA and glycerol began to increase in parallel at 30 min after the run, but at exhaustion only plasma glycerol enhanced.
2) Blood lactate increased at 10 min after the run and more at exhaustion.
3) Basal lipolytic activity of epididymal adipose tissue in vitro was not influenced by the run, while norepinephrine induced lipolysis of the adipose tissue decreased with lapse of running time. Relation between plasma FFA and lipolytic activity of epididymal adipose tissue was inverse during the run.
4) There was also inverse relation between blood lactate and lipolytic activity of adipose tissue induced with norepinephrine. From these results, it is assumed that the increase of plasma FFA during the exercise was not resulted from the increase of lipolytic activity of the adipose tissue stimulated with only norepinephrine and effects of other hormones (ACTH, Glucagon, Growth hormone and etc.) and their interactions on the lipolysis might be considered.