Studies on the Pathogenesis of Early Hepatic Changes after Endotoxin Treatment in the Rat (2) Studies on the Interaction between Hepatic Parenchymal Cells and Kupffer Cells in vitro

In order to clarify the pathogenesis of early changes of hepatic parenchymal cells after endotoxin treatment, the change of isolated parenchymal cells was studied under various conditions in vitro. The activities of lysosomal enzymes, i. e. β-glucuronidase, and of mitochondrial latent ATPase were quantified in cultured parenchymal cells. The results were as follows; (1) No significant change was observed in enzyme activities of enzymes of parenchymal cells by co-cultured with endotoxin. (2) The activities of enzymes were significanly increased in parenchymal cells co-cultured with kupffer cells and endotoxin, or in the supernatant from the culture of Kupffer cells and endotoxin. (3) In the media with endotoxin-free serum 1 hr after lethal endotoxin treatment, the activities of enzymes in parenchymal cells were increased. Therefore, secretion of the cytotoxic factor in the serum was suggested. (4) The cytotoxic factor secreted in the media incubated with Kupffer cells and endotoxin was found to be a protein by heat treatment. These findings suggest that one cause of the change in hepatic parenchymal cells after endotoxin treatment probably is the occurrence of the cytotoxic factor by the reaction of Kupffer cells and endotoxin. Namely, the interaction of Kupffer cells and parenchymal cells was realized by the existence of endotoxin