Intestinal infarction in the absence of organic vascular occlusion received increasing attention in recent years. There is strong evidence from experimental work and clinical observations that cardiac glycosides may play an important role in the pathophysiology of this disorder. Our experiments using the so called mechanical ventricular massage confirm this theory. We could demonstrate that the decrease in mesenteric arterial perfusion following the i.v. administration of ouabain is caused by extracardiac effects of the glycoside on vascular smooth muscle. The Ca++ -antagonistic compound (Verapamil) blocks and reverses the Ca++-synergistic action of the glycoside independent of the time of injection.