Prostaglandin E(1) (PGE(1)) reduces cardiac-derived TXA(2) release in ischaemic arrest in isolated working rat heart

To determine whether PGE(1) plays a beneficial role in crystalloid cardioplegia in the isolated working rat heart, twenty isolated rat hearts were studied. The hearts were subjected to 90 min cardioplegic arrest under hypothermia (25 degrees C) and 30 min reperfusion. Prior to ischaemic arrest, the amount of TXA(2) in coronary effluent, left ventricular developed pressure (LVDP), left ventricular end diastolic pressure (LVEDP), coronary flow (CF), aortic flow (AF) and cardiac output (GO) did not differ between the control and PGE(1) treated rats (28 nmol/l). However, at 30 min reperfusion, the recovery of LVDP, LVEDP, CF, AF, CO and SV in hearts from PGE(1) treated rats was more than in control hearts. TXA, levels from coronary effluent were increased during reperfusion in control rats. On the other hand, PGE(1) (28 nmol/l) inhibited the release of TXA(2) at reperfusion. The present studies confirm that the cardiac-derived TXA(2) are increased after ischaemia/reperfusion. Infusion of cardioplegia solution containing PGE(1) results in the inhibition of release of cardiac-derived TXA, and in a better preservation of cardiac function after ischaemic arrest.