一氧化氮在阿霉素肾病大鼠发病中的作用和机制

The effect and mechanism of nitric oxide in rats with adriamycin-induced nephropathy

目的 :探讨一氧化氮 (NO)在阿霉素 (ADR)肾病病鼠发病中的作用及其机制。 方法 :复制阿霉素肾病模型 ,分别用L 精氨酸 (L Arg)及N 硝酸 L 精氨酸甲基酯 (L NAME)进行干预 ,用硝酸还原酶法测定肾皮质匀浆NO代谢产物NO-2 /NO-3 水平来反映NO水平 ,用末端标记法和免疫组化法分别检测皮质部细胞凋亡和Bcl 2、Bax、c Myc蛋白表达情况 ,用原位杂交法测定皮质部细胞p5 3 mRNA转录水平。 结果 : ①ADR组肾皮质匀浆NO-2 /NO-3 水平明显低于对照组 (P <0 0 1) ,皮质部细胞凋亡数、p5 3 mRNA水平和c Myc蛋白表达均分别明显高于对照组 (P均小于 0 0 1) ,肾小管细胞Bcl 2蛋白表达明显低于对照组而Bax蛋白表达却明显高于对照组 (P均小于0 0 1)。②ADR +L Arg组肾皮质匀浆NO-2 /NO-3 水平明显高于ADR组 (P <0 0 1) ,皮质部细胞凋亡数、p5 3 mRNA水平和c Myc蛋白表达则分别明显低于ADR组 (P均小于 0 0 5 ) ,肾小管细胞Bcl 2蛋白表达明显高于ADR组而Bax蛋白表达则明显低于ADR组 (P均小于 0 0 5 )。③ADR +L NAME组肾皮质匀浆NO-2 /NO-3 水平明显低于ADR组(P <0 0 1) ,皮质部细胞凋亡数、p5 3 mRNA水平和c Myc蛋白表达均明显高于ADR组 (P均小于 0 0 5 ) ,肾小管细胞Bcl

Objective:To investigate the effect and mechanism of nitric oxide(NO) in rats with adriamycin-induced nephropathy. Methodology:Forty male Wistar rats were divided into 4 groups:Control,ADR,ADR+L-Arg and ADR+L-NAME groups.Adriamycin(7 0 mg/kg)was injected in the tail veins of the ADR,ADR+L-Arg and ADR+L-NAME groups respectively.Meanwhile,the control groups was injected an equal volume of saline.The ADR+L-Arg group was given intraperitoneal injection of L-arginine(100 mg/kg·d -1 )and the ADR+L-NAME group,received intraperitoneal injection of N-nitro-L-arginine methylester(L-NAME)(5 mg/kg·d -1 ).All rats were sacrificed on the 28 th day after the first injection.Their kidneys were examined by light and electric microscopy.The level of NO - 2/NO - 3 was detected by nitric acid reductase method.Apoptotic cells were analyzed by in situ terminal deoxymudeotidyl trasferase(TDT)mediated nick end-labeling.The level of p53 mRNA was determined by in situ hybridization.The expression of Bcl-2,Bax and c-Myc were examined by immunocytochemistry method. Results:①In ADR group,the level of renal cortex NO - 2/NO - 3 was significantly lower than of control ( P <0 01).However,the number of apoptotic cells,expression of c-Mye and level of p53-mRNA in glomeruli and tubule were significantly higher than that of control ( P <0 01).The expression of Bcl-2 in tubule was significantly decreased,while the expression of Bax was significantly increased compared with that of control ( P <0 01).②In ADR+L-Arg group,the level of renal cortex NO - 2/NO - 3 was significantly higher than that of ADR ( P <0 01).The number of apoptotic cells,expression of c-Mye and the level of p53-mRNA in glomeruli and tubule was significantly lower than that of ADR ( P <0 05).The expression of Bcl-2 in tubule was significantly increased ( P <0 05),while the expression of Bax was significantly decreased compared with that of control ( P <0 05).③In L-NAME group,the level of renal cortex NO - 2/NO - 3 was significantly lower than that of ADR ( P <0 01).The number of apoptotic cells,expression of c-Mye andlevel of p53-mRNA in glomeruli and tubule was significantly higher than that of ADR( P <0 05).The expression of Bcl-2 in tubule was significantly decreased,however,the expression of Bax was significantly increased compared with that of ADR ( P <0 05). Conclusion:ADR decreases the level of renal cortex NO markedly in rats,which induce the increase of cellular apoptosis.The L-Arginine may antagonize the action of ADR with elevating the level of NO and decreasing the cellular apoptosis,while L-NAME can stimulate the action of ADR with decreasing the level of NO and increasing the cellular apoptosis.Our results suggest that changes of NO level were correlated with the cellular apoptosis.