Endotoxins in portal blood.

Endotoxemia may complicate diseases of the bowel and liver, and is associated with the occurrence of renal failure, coagulation disorders and death. The bowel contains a large quantity of endotoxins. According to the classical hypothesis, endotoxins continuously transmigrate through the bowel mucosa, thereby entering the portal circulation. However, previous studies on portal endotoxemia were contradictory. We studied the presence of endotoxins in the portal vein in 21 consecutive patients with no diseases of the liver or the bowel, using a sensitive chromogenic endotoxin assay. In only two patients was low level portal endotoxemia detected after cross-clamping of the aorta, and subsequent reperfusion. We conclude that the normal bowel mucosa is an efficient barrier for endotoxins. Therefore, intestinal endotoxemia complicating liver disease is likely to result from enhanced permeability of the bowel mucosa.