Metabolic and hemodynamic responses of bivascularly perfused rat liver to nerve stimulation, noradrenaline, acetylcholine and glucagon in thioacetamide-induced micronodular cirrhosis.
Thioacetamide-induced rat cirrhosis was characterized by single-cell necroses, fibrosis, nodular parenchyma, decrease in parenchymal volume density and an increase in liver weight per body weight so that the total amount of parenchyma was not altered. The glycogen content was normal, and signs of decompensation were not found. Isolated livers were single-pass perfused by way of both the hepatic artery and the portal vein. In the normal livers stimulation of the nerve plexuses around the hepatic artery or portal vein (7.5 Hz; 2 msec) and infusions of noradrenaline (1 mumol/L) by way of either vessel and of acetylcholine (10 mumol/L) by way of the artery only increased glucose output, reduced both portal and arterial flow and increased the intravascular pressures. Glucagon (0.5 nmol/L) augmented glucose release and had no hemodynamic effects. In chronically thioacetamide-injured livers all stimuli caused smaller metabolic alterations per gram of liver weight and decreased portal flow more and arterial flow less with stronger enhancements of intravascular pressures than in the controls. The lowered metabolic responsiveness per gram of cirrhotic liver was largely compensated by the increase in liver weight. Thus despite massive histological alterations and pronounced increases in stimulation-dependent resistances - predominantly in the portal system - cirrhotic rat livers responded in their glucose metabolism to nervous and hormonal stimuli in almost the same manner as normal livers.