Endotoxin concentrations were measured in the portal, hepatic venous blood and abdominal aorta of six groups of rats in experimental alcoholic liver injury. Groups of animal consisted of 16 rats: I.: control group; II.: rats received one dose of E. coli 0127: B8-3 mg/kg intraperitoneally (i.p.), III.: rats received three doses of E. coli; IV.: rats intoxicated with 20% ethanol ad libitum (60 days); V.: rats intoxicated with one dose of endotoxin after 20% ethanol ingestion; VI.: animal intoxicated with 20% ethanol and three doses of E. coli 0127: B8. The highest levels of endotoxin (determined by Limulus Lysate test) were in portal venous blood--3.1 pg/ml in control group to 113.4 pg/ml in VI. group. The level of endotoxin in plasma hepatic venous blood was elevated from 0.0 pg/ml (I., II. groups) to 15.8 pg/ml (III.), 34.3 pg/ml (IV.), 49.7 pg/ml (V.) up to 75.1 pg/ml (VI.). Plasma endotoxin concentration in abdominal aorta was highest in group VI.--32.2 pg/ml. The percentage of excretion rate of endotoxin by liver function was measured on the basis of difference between plasma endotoxin levels in the prehepatic blood (portal vein) and posthepatic blood (hepatic vein). The highest activity of biochemical parameters indicating liver injury was observed in animals intoxicated with ethanol and endotoxin.