N-乙酰半胱氨酸对顺铂诱导急性肾损伤后肾脏组织氧化应激水平的影响

目的:研究顺铂(cisplatin,CDDP)诱导大鼠急性肾损伤(acute kidney injury,AKI)后肾脏组织氧化应激水平及N-乙酰半胱氨酸(N-acetylcysteine,NAC)的干预作用.方法:静脉注射CDDP制备大鼠AKI模型.大鼠随机分为空白对照组、AKI模型对照组、NAC低、中、高剂量组(50,100,200 mg· kg-1)、维生素C(Vit C)对照组(100 mg· kg-1).大鼠预先连续给药3d后,给予CDDP,再继续给药5d.测定大鼠体质量、肾质量、肾脏指数、尿蛋白排泄率.试剂盒测定肾脏组织乳酸脱氢酶(LDH)、丙二醛(MDA)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、还原型谷胱甘肽(GSH)、谷胱甘肽过氧化物酶(GSH-Px)、15-F2t-异前列烷(15-F2t-Isop)水平.免疫组化法观察8-OHdG阳性细胞.Western blot测定Cu-Zn-SOD蛋白表达.结果:与空白对照组相比,CDDP诱导AKI模型组体质量、肾质量、肾脏指数下降,尿蛋白排泄率由(0.43±0.09)g显著增加为(2.24±0.41)g,LDH,MDA,15-F2t-Isop,8-OHdG阳性细胞显著增加,CAT,SOD,GSH,GSH-Px和Cu-Zn-SOD表达显著下降(P＜0.01).与AKI模型组相比,NAC组尿蛋白排泄率降低为(0.56±0.19)g,具有显著差异.同时,AKI模型组肾脏指数,LDH,MDA,SOD,CAT,15-F2t-Isop,GSH,GSH-Px水平和8-OHdG阳性细胞数分别为(2.71±0.55) ×10-2,(6.92±0.51)KU·mg-1,(68.6±9.2) nmol·mg-1,(61±15) U·mg-1,(5.12±1.04) U·mg-1,(63.2±9.62) ng·mg-1,(159±18) nmol·mg-1,(72±15) U·mg-1,(12.25±2.23)个,NAC组200 mg·kg-1组分别为(2.96±0.32) ×10-2,(4.62±0.26) KU·mg-1,(39.5±7.9) nmol·mg-1,(109±20) U·mg-1,(9.85±1.21) U·mg-1,(41.8±4.65)ng· mg-1,(225±16) nmol· mg-1,(128±22) U·mg-1,(3.26±0.96)个,两组相比较,具有非常显著差异(P＜0.01),Cu-Zn-SOD表达显著增加(P＜0.01).结论:NAC有效拮抗CDDP的肾损伤作用,可能与其增强肾脏组织抗氧化活性、降低CDDP诱导AKI时肾脏组织氧化应激水平有关.

Effect of N-acetylcysteine on Oxidative Stress in Acute Kidney Injury Induced by Cisplatin

Objective:To investigate the effect of N-acetylcysteine (NAC) on acute injured kidney (AKI) induced by cisplatin (CDDP). Method:The rats were injected CDDP intravenously to make AKI model. The rats were randomly divided into 6 groups, including the normal control group, CDDP-induced AKI model group, NAC groups (50, 100,200 mg·kg^-1) and Vit C control group (100 mg·kg^-1). NAC and Vit C were administered once a day three days before CDDP was given. And then NAC and Vit C were continuously given ip for five days. The body weight, kidney weight, kidney index, urinary protein excretion rate of rats were determined. The commercial kits were employed to test the concentrations of lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT),reduced glutathione (GSH), glutathione peroxidase (GSH-Px), 15-F2t-isoprostane (15-F2t-Isop). Eight-OHdG positive cells were counted by immunohistochemical staining. The expression of Cu-Zn-SOD was measured by Western blot. Result:Compared with the normal control group, the weight of body and kidney, kidney index, the concentration of CAT, SOD, GSH, GSH-Px and Cu-Zn-SOD expression were significantly decreased, while urinary protein excretion rate and the concentration of LDH, MDA, 15-F2t-Isop, 8-OHdG positive cells were significantly increased (P<0.01) in the CDDP-induced kidney injury group. NAC and Vit C significantly reduced urinary protein excretion rate and the concentration of LDH, MDA, 15-F2t-Isop, 8-OHdG positive cells and increased kidney index, the concentration of CAT, SOD, GSH, GSH-Px and Cu-Zn-SOD expression compared with the AKI model group (P<0.01). Conclusion:NAC protect kidney from CDDP injury by suppressing the oxidative stress.