Response of lipogenesis and fatty acid synthetase to physical training and exhaustive exercise in rats.

The effect of physical training and exhaustive exercise on fatty acid synthesis in rat liver and adipose tissue has been investigated. Exercise training (treadmill running) significantly (p less than 0.05) decreased body wt, eipdidymal fat pad wt, adipocyte size, and hepatic fatty acid synthetase activity. Training did not significantly affect adipose tissue cell number, lipogenesis from glucose-U-14C, or fatty acid synthetase. Exercise to exhaustion immediately prior to sacrifice significantly (p less than 0.05) decreased lipogenesis from glucose-U-14C and fatty acid synthetase in adipose tissue from trained but not untrained rats. Liver fatty acid synthetase was not significantly influenced by exhaustive exercise. The results of this study indicate that rats may adapt to physical training by decreasing adipose tissue lipogenesis during exhaustive exercise. This adaptation in energy metabolism may facilitate physically trained animals in conserving blood glucose during exhaustive exercise, thereby prolonging endurance.