谷胱甘肽对汞致肾细胞凋亡影响的实验研究

目的 探讨谷胱甘肽（GSH）对汞致肾细胞凋亡的影响，进一步阐明无机汞肾损伤的分子机制。方法 昆明种小鼠24只随机分成3组，即对照组、单纯汞染毒组和GSH干预组。单纯汞染毒组小鼠腹腔注射3．0mg／kg氯化汞（HgCl2）溶液，对照组腹腔注射0．9％的氯化钠溶液，注射量为每10g体重注射0．2ml。GSH干预组于注射3．0mg／kg，HgCl2溶液前2h腹腔注射3mmol／kg谷胱甘肽溶液。24h后将小鼠颈椎错位处死，制备透射电镜标本，观察凋亡细胞形态；免疫组化法检测凋亡相关基因bcl-2和bax蛋白表达。制备单细胞悬液，用流式细胞仪进行凋亡细胞百分数分析。结果 对照组小鼠肾近曲小管细胞形态规则；单纯汞染毒组表现微绒毛排列紊乱，染色质聚集成块，核破碎释放出凋亡小体，凋亡小体被邻近细胞吞噬等典型细胞凋亡形态；GSH干预组显示接近正常的肾小管上皮细胞的形态。凋亡细胞百分数汞染毒组明显高于对照组（P〈0．01），GSH干预组明显低于汞染毒组（P〈0．01）。免疫组化检测GSH干预组bcl-2蛋白的表达明显高于汞染毒组（P〈0．01）；bax蛋白的表达显著低于汞染毒组（P〈0．01）。结论 GSH可以抵抗汞所致的肾细胞凋亡，使凋亡相关基因bcl-2蛋白的表达上调，bax蛋白的表达下调。

Effect of Glutathione on Renal Cell Apoptosis Induced by Mercury

Objective To explore the effect of glutathione on renal cell apoptosis induced by mercury.Methods 24 mice were randomly divided into three groups.The mice of control were with 0.9% saline.The mice in mercuric chloride(HgCl_2)group were intraperitoneally injected with(3.0 mg)/kg HgCl_2.Mice of glutathione group were pretreated with (3 mmol/kg) GSH solution and two hours late injected with (3.0 mg)/kg HgCl_2.Twenty-four hours later both kidneys were exposed by laparotomy and excised.With transmission electron microscope,morphologic changes of renal cell apoptosis were observed.Apoptoisis related gene expresion of bcl-2 and bax was detected by immunochemical method.Stained by propidium iodide,the percent of apoptosis cell was analyzed by flowcytometry.Results In control,the shape of renal proximal tubule epithelial cell is regular.In mercury group,micro-villi were ranged in disorder;the nuclei manifested typical apoptosis character.The morphology of renal tissue in GSH group was almost similar to the control.The percent of apoptosis cell in mercury alone was distinctively higher than that of control;those of GSH mice were significantly lower than those of mercury.The expression of bcl-2 and bax in GSH group was not significant comparing with the control.However,comparing with the mercury group,the expression of bcl-2 in GSH was dominantly increased;the expression of bax in GSH was obviously reduced.(Conclusions )GSH could prevent the apoptosis of kidney induced by mercury,the possible mechanism is bcl-2 level adjusted upward and bax level downward.