内皮素及一氧化氮在肾小球硬化大鼠肾组织的表达及意义(英文)

Expression of endothelin and nitric oxide in the renal tissue of rats with glomerulosclerosis

目的 内皮素 1(ET 1)和一氧化氮 (NO)是否参与了肾小球硬化过程尚缺乏广泛的认识。本实验通过制备阿霉素肾小球硬化大鼠模型并应用血管紧张素转换酶抑制剂 (ACEI)莱那普利和血管紧张素Ⅱ Ⅰ型受体拮抗剂芦沙坦干预 ,观察ET 1和NO在肾小球硬化过程中的变化及作用。方法 大鼠随机分成假手术 (对照 )组(C组 ) ,肾小球硬化组 (D组 ) ,肾小球硬化苯那普利治疗组 (DB组 )和肾小球硬化芦沙坦治疗组 (DL组 ) ,治疗 6周后用RT PCR分别测定肾皮质内皮素 1(ET 1)和诱导型一氧化氮合酶 (iNOS)表达 ,用Westernblotting测定ET 1和iNOS蛋白 ,免疫组化测定肾组织Ⅳ型胶原 (ColⅣ )和纤维连接蛋白 (Fn)。结果 肾小球硬化组出现明显蛋白尿、血白蛋白下降及胆固醇上升和肾小球系膜细胞增生 ,细胞外基质沉积。肾皮质ET 1mRNA和蛋白表达为对照组的 3.5 8倍和 2 .83倍 ,肾皮质iNOSmRNA和蛋白表达为对照组的 4 .2 8倍和 3.15倍 ,肾皮质ColⅣ和Fn表达也明显上调。苯那普利和芦沙坦分别治疗 6周后 ,能明显减轻肾小球硬化的生化改变及病理改变 ,同时下调了ET 1、iNOSmRNA及蛋白表达 ,ColⅣ和Fn水平也降低。结论 ET 1和NO参与了肾小球硬化进展。ET 1andiNOS的抑制阻滞了细胞外基质的沉积 ,从而可以预防肾小球硬化症的发生。

Objective It is not known whether endothelial factor-1 (ET-1) and nitric oxide (NO) are involved in glomerulosclerosis. This study aimed at studying the changes and roles of ET-1 and NO in the process of glomerulosclerosis and the effects of the angiotensin converting enzyme inhibitor (ACEI), benazepril, and the angiotension Ⅱ receptor type Ⅰ antagonist, losartan. Methods Glomerulosclerosis was induced in rats by resecting one side of the kidneys and injecting adriblastine. The rats were randomly assigned into a glomerulosclerosis group (D group), a benazepril-treated glomerulosclerosis group (DB group), and a losartan-treated glomerulosclerosis group (DL group), 10 per group. Ten rats were sham-operated (Control group) and were injected with normal saline into caudal veins. After 6 weeks of benazepril or losartan administration, the mRNA expressions of ET-1 and iNOS in renal cortex were measured by reverse transcription polymerase chain reaction (RT-PCR). The protein levels of ET-1 and iNOS in renal cortex were detected by Western blotting, and the renal tissue Collagen Ⅳ and fibronectin were measured by immunohistochemistry. Results By the 4th week of adriblastine administration, urinary protein, serum cholesterol and blood urea nitrogen increased, while serum albumin decreased in Group D compared with those of the Control group (all P< 0.05). RT-PCR and Western blotting demonstrated that the mRNA and protein expressions of ET-1 increased 3.58 and 2.83 times, and the mRNA and protein expressions of iNOS increased 4.28 and 3.15 times in the renal cortex of the Group D when compared with those of the Control group. The expressions of Collagen Ⅳ and fibronectin also significantly increased in Group D. After 6 weeks of benazepril or losartan treatment, the deposition of extracellular matrix in the Groups DB and DL was significantly reduced and mRNA and protein expressions of ET-1 and iNOS had decreased compared with those of the Group D. Meanwhile, the expressions of Collagen Ⅳ and fibronectin also decreased in the two treatment groups. Conclusions ET-1 and NO may participate in the process of glomerulosclerosis. Inhibition of ET-1 and iNOS blocks accumulation of extracellular matrix, and may avert glomerulosclerosis.