On the pathogenesis of portal hypertension in cirrhosis of the liver.

To investigate the localization of increased vascular resistance in the cirrhotic liver, blood pressures at key points in hepatic vascular pathways were measured in the cirrhotic rat produced by carbon tetrachloride injections. Blood pressures in the portal vein, the terminal portal venule, the terminal hepatic venule and the inferior vena cava were 110, 68, 28 and 20 mm H2O respectively in normal rats, and 211, 112, 34 and 24 mm H2O respectively in rats with liver cirrhosis. These values suggested that the increased vascular resistance in the cirrhotic liver was in the intrahepatic portal vein and the sinusoids, and not in the intrahepatic hepatic vein, although marked distortion of the intrahepatic hepatic vein branches was found in the cirrhotic liver. The increase in sinusoidal vascular resistance was associated with sinusoidal stenoses and a decrease in the sinusoidal space due to the hepatic cell swelling, and that in the intrahepatic portal vein might result from distortion of the peripheral branches of the vein.