THE EFFECT OF ENDOTOXIN AND LACTOBACILLUS PRETREATMENT ON PERITONEAL MACROPHAGE BEHAVIOR IN ACUTE LIVER-INJURY IN RAT

The effect of endotoxin and Lactobacillus R2LC pretreatment in acute l iver injury, induced by D-galactosamine was studied. Administration of D-galactosamine resulted in much higher luminescent activity than the control (49.24 mV vs 19.75 mV)), while there was no change detected o n the metabolic response to phorbol-12-myristate-13-acetate (PMA) stim ulation in the calorimeter. Pretreatment of animals with intraperitone al administration of heat-killed Lactobacillus resulted in higher oxyg en free radical production (105.46 mV) and a much higher metabolic res ponse to PMA in microcalorimeter (24.63 pW per cell vs 13.03 in the co ntrol). On the other hand pretreatment with endotoxin resulted in high er luminometric response to PMA compared to liver injury group (65.87 mV), and no response in the microcalorimeter at all. Phagocytic activi ty was decreased from 86 to 59% after administration of D-galactosamin e, and was not significantly influenced by any of the pretreatment mod alities. This experiment showed that pretreatment with Lactobacillus r esulted in increased macrophage metabolic activity, while endotoxin pr etreatment rendered the macrophages unresponsive to subsequent stimula tion. These findings may explain why pretreatment with endotoxin is be neficial in acute liver injury induced by D-galactosamine, but not wit h gram-positive bacteria including Lactobacillus. (C) 1996 Academic Pr ess, Inc.