亚硝酸钠预处理对急性酒精损伤的小鼠肝脏的保护作用

Protective effects of sodium nitrite preconditioning against alcohol-induced acute liver injury in mice

本文旨在研究亚硝酸钠预处理对急性酒精损伤小鼠肝脏的保护作用。将40只C57bL/6 小鼠随机分为4组:急性酒精肝损伤组腹腔注射乙醇(4.5 g/kg);亚硝酸钠预处理组腹腔注射亚硝酸钠(16 mg/kg) 12 h后,再给予乙醇(4.5 g/kg);对照组仅给予生理盐水;单纯亚硝酸钠组仅给予亚硝酸钠(16 mg/kg)。处理结束时检测肝脏指数,比色法检测肝组织超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)活性,丙二醛(MDA)含量及血清丙氨酸转氨酶(ALT)和天门冬氨酸转氨酶(AST)活性,HE和荧光标记TUNEL染色观察肝组织病理学改变,免疫组织化学染色法和Western blot检测缺氧诱导因子-1α (HIF-1α)蛋白表达。结果显示,与急性酒精肝损伤组相比,亚硝酸钠预处理组肝脏指数、血清ALT和AST活性显著下降,急性酒精损伤引起的小鼠肝组织病理学变化得到改善,坏死程度明显减轻,肝组织SOD、GSH-Px、CAT活性增加,MDA含量和细胞凋亡指数降低,肝细胞内HIF-1α蛋白表达水平显著升高。以上结果提示,亚硝酸钠预处理可减轻急性酒精肝损伤,其机制涉及氧化应激的抑制和HIF-1α蛋白水平的上调。

The purpose of the present study was to investigate the effect of sodium nitrite（SN） on alcohol-induced acute liver injury in mice.Forty male C57bL/6 mice were randomly divided into 4 groups.Acute alcohol-induced liver injury group were injected intraperitoneal（ip） with alcohol（4.5 g/kg）;SN preconditioning group were pretreated with SN（16 mg/kg,ip） for 12 h,and received alcohol（4.5 g/kg,ip） injection;Control and SN groups were treated with saline and SN,respectively.After the treatments,liver index（liver/body weight ratio） was determined.Colorimetric technique was performed to measure the serum alanine transaminase（ALT）,aspartate transaminase（AST）,liver superoxide dismutase（SOD）,glutathione peroxidase（GSH-Px）,catalase（CAT） activities,as well as malondialdehyde（MDA） content.The pathological index of liver tissue was assayed by HE and TUNEL fluorometric staining.Using Western blot and immunohistochemistry staining,the expression of hypoxia-inducible factor-1α（HIF-1α） protein was detected.The results showed that,compared with acute alcohol-induced liver injury group,pretreatment with low doses of SN decreased liver index and serum levels of ALT and AST,weakened acute alcohol-induced hepatocyte necrosis,improved pathological changes in liver tissue,increased live tissue SOD,GSH-Px and CAT activities,reduced MDAcontent and apoptosis index of hepatocytes,and up-regulated HIF-1α protein level in liver tissue.These results suggest that the pretreatment of SN can protect hepatocytes against alcohol-induced acute injury,and the protective mechanism involves inhibition of oxidative stress and up-regulation of HIF-1α protein level.