Effects of N-acetylcysteine on the lipopolysaccharide-induced MAPK phosphorylation in mouse liver / 中国病理生理杂志

ABSTRACT

AIM:To investigate the effects of antioxidant N-acetylcysteine(NAC)on the lipopolysaccharide(LPS)-induced MAPK phosphorylation in mouse liver.METHODS:54 male mice were divided into three groupscontrol(n=6),0.9% sodium chloride 0.2 mL ip;LPS group(n=24)LPS 5 mg ip;NAC+LPS group(n=24)NAC 150 mg?kg-1?d-1 ip,for 3 d;LPS 5 mg ip after 1 h of NAC administration at 3rd day.The liver was excised with carbrital anesthesia after LPS or 0.9 % sodium chloride injection at 0.5 h,1 h,2 h and 6 h for GSH and MDA assays.The protein extracted from liver was assayed for the phosphorylation of MEK1/2,ERK1/2,p38 MAPK by Western blotting.TNF-? in liver was assayed by radioimmunoassay.RESULTS:MDA in the liver was decreased remarkably and the GSH in the liver was increased significantly by NAC pretreatment.The phosphorylation of MEK1/2,ERK1/2 and p38 MAPK in liver were inhibited significantly by NAC pretreatment after LPS challenge.Meanwhile,TNF-? in liver was decreased markedly.CONCLUSION:Reactive oxygen species plays a critical role in MAPK signaling during the LPS induced acute liver injury.NAC partially inhibits LPS-induced MAPK signaling by antioxidant effect and decreases TNF-? production.