Venous-Arteriolar Response in the Canine Liver,∗

Abstract

Summary

A series of experiments has been carried out on the dog-perfused liver. The liver was continuously weighed and perfused at constant flow with arterial blood through the hepatic artery, and venous blood through the portal vein. Hepatic vein pressure was increased in steps by means of partial out-flow obstruction with a screw clamp adjustment. Hepatic artery pressure was seen to increase in a profound fashion as a function of elevated hepatic vein pressure in 3 of 5 experiments. An increase in hepatic artery segment resistance occurred, presumably on the basis of a venous arteriolar (myogenic) response. The vascular segment between hepatic and portal veins exhibited only passive changes as a result of increased venous transmural pressure. The peculiar arterial response would serve to decrease flow through the hepatic arterial system in the face of liver pooling in ceratin stress states previously observed in the canine species.