CARDIOPROTECTIVE EFFECTS OF BERAPROST SODIUM AGAINST EXPERIMENTAL-ISCHEMIA AND REPERFUSION AS COMPARED WITH PROPRANOLOL AND DILTIAZEM

We compared the cardioprotective effects during experimental ischemia and reperfusion of beraprost sodium (beraprost), a prostacyclin analog , with those of propranolol and diltiazem. Coronary perfused guinea-pi g right ventricular free wall preparations were subjected to 30min no- flow ischemia with or without drugs, followed by 60min reperfusion wit hout drugs. In control preparations, decrease in contractile force and increase in resting tension were observed during the no-flow period. On reperfusion, contractile force returned to less than 50% of preisch emic values. Beraprost, at 0.1 mu M, showed no inotropic effect under normoxic condition and during the no-flow period, but significantly en hanced the recovery of contractile force after reperfusion to about 80 % of control values. Propranolol (30 mu M) or diltiazem (10 mu M) prod uced similar enhancement of recovery of contractile force after reperf usion, but these two drugs decreased the contractile force under normo xic conditions to less than 20% of control values. Thus, the cardiopro tective effect of beraprost was different from those of propranolol an d diltiazem in that it was not accompanied by cardiosuppressive effect s.