EFFECT OF VOLUNTARY EXERCISE ON PANCREATIC FUNCTION OF RATS

To clarify the effects of long term exercise on digestion and absorption, pancreatic and digestion and absorption function were assessed in rats after prolonged voluntary exercise. Body weight in the non-exercise group was greater than that in the exercise group, while there was no significant difference in food intake between the two groups during the test period. The weight of the pancreas in the exercise group was significantly greater than that in the non-exercise group, but there were no marked differences in the weight of other organs between the two groups. Basic pancreaticobile juice output in the exercise group was about 1.5 times that of the non-exercise group, and the levels of protein and enzymes released in the juice of the exercise group were significantly higher than in the non-exercise group. The DNA level per gram of pancreatic tissue in the exercise group was significantly lower than in the non-exercise group. Electron micrographic observation of pancreatic acinar cells revealed hyperplasia of the endoplasmic reticulum and mitochondria in the exercise group. Gastric emptying and the rate of digestion and absorption in the exercise group were markedly greater than in the non-exercise group. These results suggest that long-term exercise induces pancreatic hyperfunction, along with an increase in the weight of the pancreas, and eventually contributes to decreasing the time for digestion and absorption. The results also indicate that the exercise-related increase in weight of the pancreas was due to cellular hypertrophy, rather than to an increase in the number of cells.