环磷酰胺激活小鼠肝微粒体谷胱甘肽S-转移酶Ⅰ的机制研究  

Activation of mouse liver microsomal glutathione S-transferaseⅠ by cyclophosphamide treatment in vivo

作　　者：郑英[1,2] 邹晓华[2] 付再林[2] 方慧[2] 陈素红[3] 吕圭源[1] 

机构地区：[1]浙江中医药大学,浙江杭州310053 [2]解放军第117医院,浙江杭州310013 [3]温州医学院药学院,浙江温州325035

出　　处：《中国药理学通报》2013年第10期1387-1390,共4页Chinese Pharmacological Bulletin

基　　金：国家自然科学基金资助项目(No 30070904)

摘　　要：目的探讨环磷酰胺(CP)在体内对小鼠肝微粒体谷胱甘肽S-转移酶Ⅰ(mGST-Ⅰ)活性的影响及其可能的机制。方法用苯巴比妥75 mg·kg-1诱导小鼠CYP2B后,ip CP,测定9 h内mGST-Ⅰ酶活性,观察二巯基丁二醇(DTT)对酶激活的逆转作用和巯基烷化剂N-乙基马来酰亚胺(NEM)对酶再激活效应,用SDS-PAGE和负染凝胶法评价CP对mGST-Ⅰ蛋白表达的影响。结果 CP引起小鼠微粒体中mGST-Ⅰ活性增加;NEM在mGST-Ⅰ半胱氨酸-49-巯基(cys-49-SH)上的活化效应减弱,而CP引起的mGST-Ⅰ激活效应不被二硫键还原剂DTT逆转。激活的mGST-Ⅰ电泳图谱未见蛋白分子量变迁及蛋白表达增加。结论大剂量CP致mGST-Ⅰ激活效应机制主要是酶分子cys-49-SH上单个巯基的修饰作用。Aim To investigate the effects of cyclo- phosphamide （CP） on the activities of mierosomal glutathione-S-transferase- I （ mGST- I ） in mouse livers and demonstrate its potential mechanism in vivo. Methods Mice pretreated with phenobarbital, a typi- cal inducer of hepatic cytochrome, were administrated CP in ip manner. After CP was given, the activities of mGST- I were measured during the following 9 hours. Dithiothreitol （DTT） and N-ethylmaleimind （NEM） were chosen to characterize the activation manner of mGST-｜. The SDS-PAGE gel electrophoresis and negative dye method were used to evaluate the changes in molecular weight and protein expression. ResultsmGST- I activities were increased after CP treatment. The re-activation effect of NEM on the site of cys-49- SH was significantly down-regulated. The increase of mGST-I activities couldn＇t be reversed by disulfide bonds reductant DTT, neither. There were no obvious changes in the molecular weight and expression of mGST- I . Conclusion The results suggest that high dose CP induces mGST- I activation via modifying the site of cys-49-SH.

关 键 词：环磷酰胺 微粒体 谷胱甘肽S-转移酶Ⅰ 二巯基丁二醇 N-乙基马来酰亚胺 半胱氨酸-49-巯基 机制 

分 类 号：R-332[医药卫生] R329.24