THE EFFECT OF THE PURINE BASE DIURETICS ON THE CORONARY FLOW

Abstract

Reports based on experimental work concerning the effect of the salts of theobromine and caffeine, and later of theophylline, on the volume flow in the coronary arteries, began to appear shortly after the clinical report of Askanazy¹in 1895. Taken as a whole, the collective evidence points definitely to a vasodilator action of these drugs on the coronary vessels. The work has been done almost entirely on preparations of the isolated heart, and with suspension preparations of arterial strips. While, for the most part, the results of such experiments can safely be taken as evidence of the actual pharmacologic effect of the drug clinically, there are certain objections. Especially is this true when there is a possibility that the action is a direct one on the vessel wall. In perfusion experiments a constant supply of the drug is reaching the tissues in a fixed dilution, permitting any amount to be