Prostaglandin response in the exercise conditioned rat.

Thrombin- and collagen-induced thromboxane A2 (TxA2) production were significantly reduced in washed platelets from exercise-trained rats as compared to sedentary controls. No consistant differences were found in the synthesis of prostacyclin (PGI2) from endogenous arachidonate in strips of aorta. Isolated hearts perfused by the "Langendorff" method respond to bolus injections of PGI2 with a decreased perfusion pressure. Hearts from exercised-trained animals were more responsive than those from sedentary animals to the vasodilating effects of PGI2. The increased ratio of PGI2/TxA2 and the increased responsiveness of the coronary vasculature to PGI2 seen in the trained rats may provide protection from cardiovascular disease.