EFFECT OF RUNNING TRAINING ON BROWN ADIPOSE-TISSUE ACTIVITY IN RATS -A REEVALUATION

The effect was investigated of running training on the thermogenic act ivity of brown adipose tissue (BAT) in rats. The exercised rats were t rained on a rodent treadmill for 5 days per week and a total of 9 week s. After the training, a significantly lower rate of increase in body weight was found, suggesting some training effect, whereas the trainin g failed to induce a decrease in BAT mass. As previously reported (Yam ashita, Yamamoto et nl., 1993), there was also a markedly lower expres sion of uncoupling protein (UCP) mRNA in BAT from trained rats; nevert heless, no definite effect of the running training was noted on either UCP content or guanosine 5'-diphosphate binding in the mitochondria r ecovered from BAT. The results obtained suggest that running training has no overt effect on the thermogenic activity of BAT in rats.