PD 122860 is a dihydropyridine with calcium channel blocking and sodium channel stimulating properties. In the rat heart, PD 122860 increased left ventricular contractility, decreased coronary resistance and altered the shape of the electrocardiogram T-wave. PD 122860 selectively relaxed potassium-contracted aortic rings and inhibited [3H]nitrendipine binding to rat brain membranes.