The organ distribution of [3H]endotoxin following partial hepatectomy

3H-labeled endotoxin was intravenously injected into Wistar rats 24 hours following 70% hepatectomy and also into the normal rats. They were sacrificed 12 hours, 24 hours or 5 days after the injection. Microscopical autoradiography was performed on the rats' organs. The distribution of endotoxin in the organs was investigated by quantitatively measuring their radioactivity. Endotoxin was taken up mainly by Kupffer cells of the liver in all the groups. Endotoxin was observed also in macrophages of the spleen and the lung in all the groups. The amount of endotoxin per 1 g organ weight of the hepatectomized rat was significantly smaller in the liver, and significantly larger in the spleen, lung and blood (per 1 ml) than that of the control groups early after hepatectomy. These differences of the organ accumulation of endotoxin between groups diminished 5 days later. Deficient tolerance of the liver to endotoxin at the peak phase of regeneration following partial hepatectomy was suggested.