PM2.5致大鼠肾脏氧化损伤效应研究

PM2.5-induced oxidative damages in kidney tissues of rats

目的通过建立大鼠PM2.5经呼吸道亚慢性染毒模型,探讨PM2.5对大鼠肾脏的氧化损伤效应。方法将SPF级雄性大鼠20只随机分为对照组(生理盐水)和PM2.5染毒组(染毒剂量10 mg/kg),每组10只。采用气管注入法染毒,每周1次,连续染毒24周。采用试剂盒测定肾脏丙二醛(MDA)含量、超氧化物歧化酶(SOD)及谷胱甘肽过氧化物酶(GSH-Px)活力,采用免疫组织化学方法检测肾脏Bcl-2、Bax蛋白表达水平,采用TUNEL法检测肾脏细胞凋亡情况,采用HE染色对肾组织进行病理形态学检测。结果与对照组比较,PM2.5染毒组大鼠肾脏SOD及GSH-Px活力均降低,MDA含量升高,差异有统计学意义(P<0.05)。与对照组比较,PM2.5染毒组大鼠肾脏Bcl-2蛋白表达水平下降,Bax蛋白表达水平升高,差异有统计学意义(P<0.05)。TUNEL检测结果显示,PM2.5染毒组肾脏细胞凋亡率高于对照组,差异有统计学意义(P<0.05);PM2.5染毒组肾脏出现明显的病理形态学改变。结论PM2.5可致大鼠肾脏发生明显的氧化损伤效应。

Objective To understand PM2.5-induced oxidative damages in the kidney tissues of rats exposed to subchronic intratracheal instillation.Methods A total of 20 male SPF rats were randomly divided into PM2.5-exposed group and the control group,10 animals in each.The rats were exposed to PM2.5 through intratracheal instillation of PM2.5-suspension,10 mg/kg,and the control group received saline with an equal volume,once a week,for 24 times.After the exposure,the kidney coefficients were calculated;Kidney SOD and GSH-Px activity and MDA content were determined by using a kit.The protein expression levels of Bcl-2 and Bax in the kidney were determined by immunohistochemical method.Apoptosis of renal cells was tested by TUNEL.Pathological examination of renal tissue was performed by H-E staining.Results Compared with the control group,the activities of SOD and GSH-Px in the kidney of the rats in PM2.5-exposed group decreased,while the content of MDA in the kidney increased significantly(P<0.05).Compared with the control group,the protein expression of Bcl-2 in kidneys of rats in PM2.5-exposed group was decreased,while the protein expression of Bax was increased,with significant difference(P<0.05).TUNEL assay results showed that the percentage of apoptotic kidney cells in PM2.5-exposed group was significantly higher than that in the control group.There was obvious pathological changes in the kidney in PM2.5-exposed group.Conclusion PM2.5 exposure can cause oxidative damage in kidney tissues of rats.