Coronary vasodilation and positive inotropic effect of non steroidal cardiotonics

The effects of several cardiotonic agents (ARL-115, Amrinone, RMI 82-249, Milrinone, CI-914, RO 13-6438 and APP 201-533) were compared with those of ouabain on pig isolated coronary artery, guinea-pig isolated atria and guinea-pig perfused heart to compare vasodilatory and inotropic responses. Like ouabain, all compounds tested produce positive inotropic and chronotropic effects in isolated atria and on perfused heart, and induce relaxation in precontracted pig coronary artery and coronary vasodilation on perfused heart, except ouabain which induces vasoconstriction. The results indicate that non steroidal cardiotonics exert positive inotropic and coronary vasodilatory effects.