Effects of endurance exercise on carnitine palmitoyltransferase I from rat heart, skeletal muscle and liver mitochondria.

Prolonged physical exercise increased the activity of carnitine palmitoyltransferase I in rat heart and skeletal muscle mitochondria, whereas enzyme sensitivity to inhibition by malonyl-CoA remained unchanged. Nevertheless, inhibition of carnitine palmitoyltransferase I activity by small decreases in pH was attenuated in heart and skeletal muscle mitochondria from exercised animals. Liver enzyme did not suffer any alteration by endurance exercise.