[Studies on the pre- and posthepatic plasma histamine concentrations and their possible pathophysiological effects in...

Fluorometric estimations of plasma histamine in the peripheral venous blood were performed in a control group of 16 subjects with normal liver values and normal liver biopsy specimen. Two further groups with liver changes were studied: Ten patients with fatty liver (stage I-II) and 22 cases suffering from liver cirrhosis, including 7 patients with portocaval shunt. Additionally, plasma histamine concentrations were determined in the blood of the portal vein, hepatic vein, cubital vein and in the femoral artery of another 11 normal subjects and 8 cirrhotic patients, some of them with portocaval shunt. The elimination of histamine by the liver was calculated. In healthy humans about two thirds (67.8 plus or minus 11.4 per cent; n=11) of the histamine content in the portal vein is eliminated by liver passage. This is due mainly to liver uptake and catabolism of histamine. It could be shown, that the elimination rate (41.0 plus or minus 15.1 per cent, n=8) is diminished in cirrhotic livers. Therefore, the plasma histamine content measured in the peripheral venous blood is significantly higher (p less than 0.001) in cirrhotic patients (1.2 +/- 0.3 ng/ml; n=22) than in healthy subjects (0.7 +/0 0.2 ng/ml; n=16). The expected pathophysiological effects of the elevated plasma histamine levels in liver cirrhosis are discussed with respect to circulatory changes ("hyperdynamic circulation") and their possible role in the development of "hepatogenic" ulcers of the stomach.