Pancreatic insulin response in relation to exercise training.

The present study was undertaken to measure the effects of exercise training on pancreatic insulin secretion in response to glucose and nonglucose stimuli. Wistar female rats with an initial body weight of approximately 180 g were divided into trained and sedentary groups. After a period of 10 weeks of training, glucose-, tolbutamide-, and arginine-tolerance tests were performed in vivo in both trained and untrained animals. The tests were done in nonanesthetized animals 40 h after the last exercise bout. It was found that exercise training leads to a diminution of plasma insulin levels after either glucose, tolbutamide, or arginine administration. These results present direct evidence that exercise training reduces plasma insulin response not only to glucose but also to nonglucidic secretagogues.