Distribution of TNF endogenously induced by various immunopotentiators and Lactobacillus casei in mice.

Intravenous administration of heat-killed Lactobacillus casei YIT 9018 (LC) elicited endogenous cytotoxic factor (CF) production in ICR mice, peaking in serum after 2 h and declining gradually to basal level at 23 h. The endogenous CF production was significantly enhanced by priming with high molecular-weight lignins and glucans, but not by phenylpropenoid precursors or partially hydrolyzed products of glucans. The extent of stimulation of CF production by these priming agents was positively related to that of tumor necrosis factor (TNF) production, as judged by enzyme-linked immunosorbent assay. Endogenously produced TNF was concentrated more in liver, lung and intestine, as well as in serum, than in other organs. Histochemical examination revealed a significant increase in the number and swelling of Kupffer cells and sinusoidal endothelium in the liver of the treated mice.