Drugs and muscular pathways of pyruvate metabolism adapted to endurance training.

Limited experimental data are so far available on drug interference at muscular level on the pathways of pyruvate metabolism activated by training. In this study, the effect of chronic treatment with caffeine and papaverine on the activity of the muscular malic enzyme, lactate dehydrogenase and glutamate-pyruvate transaminase was evaluated in the trained rat. In trained animals these drugs did not induce any significant change in the enzymatic activities studied as a whole, and particularly in glutamate-pyruvate transaminase related to an important alternative pathway of pyruvate metabolism.