Fate of 3H-labeled endotoxin in partially hepatectomised rats.

Organ distribution of endotoxin was compared in normal and previously hepatectomised rats after administration of endotoxin lipopolysaccharide labeled at the galactose moiety. Most of the radioactivity was found in the liver in both cases, but total recovery was much higher in the organs of normal rats. In the liver, the amount of endotoxin per total organ and per 1 g organ weight was significantly reduced in the hepatectomised rats as compared with the intact controls. In normal rats, the radioactivity decreased 12 to 24 hours in the liver, but in the hepatectomised rats, no significant change was observed during this period. The total radioactivity in the lungs, spleen and blood (1 ml), as well as that per unit weight bases, was significantly higher in the hepatectomised rat than in normal rats. These results and autoradiographical studies suggest that endotoxin clearance activity of Kupffer cells in the liver is decreased by partial hepatectomy of the rats at the peak phase of regeneration, and that remaining endotoxin flow out of the liver is disposed mainly by the macrophages in the spleen.