Prostaglandin E1 (PGE1) reduces cardiac-derived TXA2 release in ischaemic arrest in isolated working rat heart

To determine whether PGE1 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 °C) and 30 min reperfusion. Prior to ischaemic arrest, the amount of TXA2 in coronary effluent, left ventricular developed pressure (LVDP), left ventricular end diastolic pressure (LVEDP), coronary flow (CF), aortic flow (AF) and cardiac output (CO) did not differ between the control and PGE1 treated rats (28 nmol/l). However, at 30 min reperfusion, the recovery of LVDP, LVEDP, CF, AF, CO and SV in hearts from PGE1 treated rats was more than in control hearts. TXA2 levels from coronary effluent were increased during reperfusion in control rats. On the other hand, PGE1 (28 nmol/l) inhibited the release of TXA2 at reperfusion. The present studies confirm that the cardiac-derived TXA2 are increased after ischaemia/reperfusion. Infusion of cardioplegia solution containing PGE1 results in the inhibition of release of cardiac-derived TXA2 and in a better preservation of cardiac function after ischaemic arrest.