Abstract:To examine the significance of fibrous septa of the liver for hepatic circulatory disturbance, haemodynamic changes were investigated in rats with septal fibrosis induced with horse serum injections. The fibrotic liver showed thin fibrous bands originating in the vicinity of the peripheral branches of the hepatic vein connected with each other and partly with the portal triads, without conspicuous periportal, pericentral or perisinusoidal fibrosis. There was no evidence of hepatic cell enlargement, disarrangement of hepatic cell plates or narrowing of the sinusoids in the fibrotic livers. Portal vascular resistance, bile production and hepatic oxygen consumption, which were measured by an isolated liver perfusion method, were much the same in the normal and the fibrotic livers. Moreover, there was no significant difference inin vivoblood pressures of the portal vein, the terminal portal venule, the terminal hepatic venule and the inferior vena cava between the normal and the fibrotic rats. These data suggest that septal fibrosis in itself does not disturb hepatic circulation.