Hemodynamic characterization in experimental liver cirrhosis induced by thioacetamide administration.

Systemic and splanchnic hemodynamics in experimental liver cirrhosis in rats induced by thioacetamide were evaluated by the radioactive microsphere method. Cardiac output and regional blood flow were measured in conscious and anesthetized control and cirrhotic rats. The conscious thioacetamide-treated rats had hyperdynamic circulation with an increased cardiac index (300 +/- 10 vs 258 +/- 3 ml/min/kg body weight, P < 0.001) and increased portal venous inflow compared with the controls (64.60 +/- 2.4 vs 48.39 +/- 0.88 ml/min/kg body weight, P < 0.001). Under pentobarbital anesthesia, the hyperdynamic circulation of the cirrhotic rats was maintained, with an increased cardiac index (276 +/- 7 vs 229 +/- 5 ml/min/kg body weight, P < 0.001) and increased protal venous inflow compared with the controls (72.47 +/- 3.0 vs 54.08 +/- 1.2 ml/min/kg body weight, P < 0.001). Portal pressure, portal venous resistance, and portal systemic shunting increased significantly while splanchnic arterial resistance decreased significantly in cirrhotic rats. Thioacetamide-induced cirrhosis is a useful model for the hemodynamic study of portal hypertension and remains useful in hemodynamic studies in the basal state under pentobarbital anesthesia.