TLR4 expression in the kidney of rats with multiple organ dysfunction syndrome / 中华急诊医学杂志

ABSTRACT

Objective To determine the level of toll-like receptor4 (TLR4) in the kidney of rats with the Multiple Organ Dysfunction Syndrome (MODS),and to investigate the early phase of kidney damage in MODS.Methods The experiment was done at experimental center of medical college of Three Gorges University.Forty Adult male Sprague-Dawley (SD) rats were randomly (random number) divided into two groups,namely the normal control group and the MODS model group.The rats of model group were further divided into four sub-groups as per different intervals (6 h,12 h,24 h and 48 h),and there were 8 rats in each groups.The animal models of MODS were established by two hits,the left eyeball of each model rat was removed to bleed to 2 mL/100 g,and four hours later,Lipopolysaccharide ( LPS,5 mg/kg) was injected into intraperitoneal cavity of model rats.The same volume of saline was injected intraperitoneally into rats of control group.All rats were sacrificed at various intervals.The histological changes in the kidney tissue were observed by naked eye and under light microscope.The lever of TLR4 proteins in serum and kidney tissue were detected by using flow cytometry (FCM).One-way ANOVA was used for comparison among multiple groups.Results (1) There were no histopatholagical changes in kidney of rats in control group,and the kidney injury was serious in rats with MODS.(2) Compared with the rots of control group,the level of TLR4 in kidney tissue of rats with MODS increased at 6 hours and reached peak 12 hours later ( P ＜ 0.01 ),and then decreased 24 hours ( P ＜ 0.01 ).There was no significant difference in levd of TLR4 between two groups 6 and 48 hours.Compared with the rats of control group,the level of TLR4 in peripheral blood leucocyte of rats with MODS increased significantly 6 ～ 48 hours after LPS ( P ＜ 0.01 ).The concentrations of serum and kidney tissue TLR4 proteins were positively correlated with each other ( r =0.893,P ＜ 0.05 ).Conclusions The level of TLR4 markedly increased in the kidney tissue at early stage of MODS,and the TLR4 may play an important role in the pathogenesis of kidney injury in MODS.