Effect of beraprost sodium on changes in action potentials during hypoxia as compared with propranolol, diltiazem and glibenclamide in guinea-pig ventricular muscle.

The inhibitory effect of beraprost on the transmembrane action potentials was compared with other cardioprotective drugs during hypoxia in guinea-pig isolated right ventricular muscle. Glibenclamide, like beraprost, inhibited the decrease of the action potential duration, but propanolol and diltiazem did not affect this decrease during hypoxia. In beraprost-treated preparations, the decrease of the myocardial K+ content during hypoxia was inhibited. Furthermore, beraprost prevented the action potential shortening during metabolic inhibition by 2,4-dinitrophenol. It is suggested that beraprost may inhibit the hypoxia- and 2,4-dinitrophenol-induced shortening of the action potential duration by preserving the muscular ATP level. Accordingly, beraprost may have beneficial effects both during hypoxia and metabolic inhibition.