On the protective role of the liver in the hypotensive state following intestinal ischemia.

Regional intestinal hypotension (arterial inflow pressure about 30 mmHg) was induced in cats by partially occluding the superior mesenteric artery with an adjustable clamp. The superior mesenteric vein was cannulated and the intestinal venous outflow recorded by a drop counter. The intestinal venous blood bypassed in one series the liver and was returned to the animal via the jugular vein. In two other series it was returned via the portal vein and in one of these also the hepatic arterial pressure was kept at 30 mmHg. Following two hours of regional intestinal shock a general cardiovascular derangement was evident in all series. This was not influenced by directing the intestinal venous blood flow through a normotensive or hypotensive liver. Characteristic intestinal mucosal lesions were found in all series. It is concluded that bypassing or directing the intestinal venous blood through a normotensive or hypotensive liver did not affect the local and general cardiovascular effects of regional intestinal hypotension.