Objective      To probe into the protective mechanism of LPS tolerance-related GSK-3 inhibition on endotoxin-induced acute liver injury in rats with endotoxemia.       Methods      After the SD rat models of LPS tolerance with or without GSK-3 inhibitor LiCl pretreatment were established

and the mRNA levels of TNF-α and IL-10 in

hepatic tissue were measured by semi-quantitative RT-PCR in the normal rats

and above model groups. The activity of myeloperoxidase (MPO) in the liver tissue was detected by using special kit to evaluate the neutrophils infiltration in the liver tissue. Kupffer cells were isolated by Ficoll density gradient centrifugation

and the cell models of endotoxin tolerance and GSK-3 inhibition (LiCl and insulin) were established. The phagocytosis activity of Kupffer cells was measured with Neutral Red assy. Confocal analysis and Western blotting were used to observe the subcellular localization and nuclear translocation of NF-κB p65.       Results      LPS tolerance as well as GSK-3 inhibitor LiCl pretreatment decreased the up-regulated TNF-α mRNA (

P

0.05) and promoted IL-10 mRNA (

P

0.05) induced by high-dosed endotoxin attack

and the enhanced activity of MPO was also decreased during this process (

P

0.05). On the other hand

both endotoxin tolerance and GSK-3 inhibition (LiCl and insulin) enhanced the phagocytic activity of Kupffer cells (

P

0.05). Both LPS tolerance and GSK-3 inhibition LiCl decreased the nuclear translocation of NF-κB p65 induced by large-dosed LPS (

P

0.05).       Conclusion      The inhibition of GSK-3 functional activity induced by LPS tolerance may be one of the protective mechanisms against endotoxin induced acute liver injury

probably via affecting nuclear translocation of NF-κB p65

secretion of inflammation related cytokines

infiltration of neutrophils

phagocytic activity of Kupffer cells and other downstream events.