The Effect Of Endotoxin Tolerance On The Galn/LPS Induced MAPK And STAT Signal Transduction

Aim: To investigate the effect of endotoxin tolerance on the LPS-induced acute liver injury and Galn/LPS induced MAPK and STAT signal transduction.Methods: The experiment (Exp) 1. The Kunming mice were divided randomly into three groups. (1) control : 0.9% Sodium Chloride 0.2 ml, i.p..(2)Galn/LPS group: Galn13mg/LPS 3μg/mouse, i.p.. (3) LPS+ Galn/LPS(ETT)group: LPS 2mg/kg was administered three consecutive intraperitoneal injections at 24-h intervals. All animals were treated with i.p injection of Galn 13 mg/LPS 3μg/mouse, 72h later. The blood was gathered from eye vein and liver was excised with carbrital anaesthesia after LPS or 0.9% Sodium Chloride injected at 0.5h(n=4), 1.5h (n=8) and 6.0h (n=10) for ALT, MDA,TNF-α, GSSG, GSH and GSH/GSSG assays for each groups.Exp 2.The experimental mice were divided randomly into two groups. (1)control: 0.9% Sodium Chloride 0.2 ml, i.p..(2)LPS+ Galn/LPS(ETT)group: LPS 2mg/kg was administered three consecutive intraperitoneal injections at 24-h intervals.Before the execution, India ink 1:5 diluted with germ free physiological saline was injected into the vail vein in each group rats. To calculate phagocytic index k and its correction a.Exp 3.The animal and groups were same as Exp 1. (1) control : 0.9% Sodium Chloride 0.2 ml, i.p.. (2) Galn/LPS group: Galn13mg/LPS3μg/mouse i.p.. (3) LPS+ Galn/LPS(ETT)group: LPS 2mg/kg was administered three consecutive intraperitoneal injections at 24-h intervals. All animals were treated with i.p injection of Galn/LPS (13 mg/3μg/mouse ) 72h later. The livers were excised in anaesthetic state by carbrital after LPS or 0.9% Sodium Chloride injected at 0.5h, 1.5h and 6h and the protein extracted from livers was assayed for the phosphorylation level of MEK1/2, ERK1/2, p38MAPK, STAT1, STAT3 and expression of SHIP and inducible nitric oxide synthase(iNOS)by western blotting analysis. Results:Galn/LPS-induced acute liver injury was attenuated significantly by LPS pretreatment.The plasma ALT activity and liver MDA,GSSG contant were decreased remarkably by LPS preteatment and the GSH and GSH/GSSG assays of liver was increased significantly. In Galn/LPS treatment groups, LPS stimulation increased plasma level of TNF-αexpression in the liver, in which the peak values of plasma TNF-αin ETT group were much lower than Galn/LPS group (p<0.05).The change of kupffer cell index of phagocytosis correction a between control and ETT group is no significance difference(p>0.05). p-MEK1/2 and p-ERK1/2 was heightened significantly at 0.5h and maintain at the level until 6h after LPS stimulation. p-p38MAPK was the highest at 0.5h and decreased...