Abstract
THE liver acts as a selective barrier between the gastrointestinal tract and the systemic circulation, metabolizing, detoxifying and elaborating for further physiologic disposition various substances that enter the portal blood during digestion. Unquestionably, the rich and complex vasculature of the liver serves these processes by providing an adequate supply of oxygen and raw materials. In addition, this extensive vascularity itself may indicate an important role in cardiovascular dynamics.Unfortunately, very little is known about the physiology of the hepatic circulation, largely because it is so inaccessible. Traumatic surgical manipulations required for its study are obviously inapplicable in the study of . . .