Effect of furosemide on canine inferior mesenteric blood flow

The administration of diuretics to patients receiving cardiac glycosides has been reported to be a contributing factor in the incidence of nonocclusive mesenteric infarction. Presumably, the loss of fluid induced by the diuretics results in a decrease in blood flow to the intestines. This, combined with the vasoconstrictor action of the glycosides, can result in too great a decrease in blood flow and hence the development of an infarct. The ability of diuretics to alter intestinal circulation is supported by animal studies which have shown that blood flow in the superior mesenteric artery is decreased after the administration of furosemide. Since intestinal blood flow is also, in part, supplied by the inferior mesenteric artery, it was of interest to determine the effect of the administration of furosemide on blood flow in this vessel. Following intravenous administration of furosemide (2 mg/kg), inferior mesenteric flow was found to be decreased significantly at 10 minutes and it continued to decline until approximately 40 minutes after administration of the diuretic. Blood pressure was elevated slightly (less than 10 mm Hg) for the first 30 minutes after the administration of furosemide. It would seem likely that the reduction in inferior mesenteric blood flow following administration of furosemide is probably caused by the same factors which mediate the furosemide-induced decrease in superior mesenteric blood flow.