曲尼司特对阿霉素肾病大鼠肾脏保护作用的实验研究

目的研究曲尼司特对阿霉素肾病肾小球硬化大鼠的肾脏保护作用,并探讨其可能的机制。方法雄性SD大鼠24只,随机分为正常对照组、模型组、曲尼司特组和安博维组,采用单侧肾切除加尾静脉注射阿霉素5mg/kg的方法建立阿霉素肾病模型。观察各组大鼠24h尿蛋白定量、血尿素氮(BUN)、血肌酐(Scr)及肾脏病理的变化。应用免疫组化方法测定肾组织转化生长因子β1(TGF-β1)和金属蛋白酶组织抑制因子-1(TIMP-1)的表达,应用原位杂交方法测定肾组织α-平滑肌肌动蛋白(α-SMA)mRNA的表达。结果曲尼司特能减少阿霉素肾病大鼠的尿蛋白,延缓Scr上升;减轻基质增生和肾小球硬化;与模型组比较,曲尼司特下调阿霉素肾病大鼠肾组织中TGF-β1〔(0.6927±0.169)vs(0.4540±0.168)〕、TIMP-1〔(0.1615±0.077)vs(0.0869±0.041)〕、α-SMA mRNA〔(0.2693±0.082)vs(0.1407±0.045)〕的表达。结论曲尼司特可能通过下调阿霉素肾病大鼠肾组织中TGF-β1、TIMP-1的表达以及抑制肾脏细胞表型转分化,调节细胞外基质的生成与降解,从而减轻肾脏病理损害,发挥其肾脏保护作用。

Experimental Study in Renal Protective Effect of Tranilast on Rats with Adriamycin Nephropathy

OBJECTIVE: To investigate the effect and mechanism of tranilast on the adriamycin-induced nephrotic syndrome of rats. METHODS: Twenty four rats were randomly divided into 4 groups: normal control group, model group, irbesartan treatment group and tranilast treatment group. The rats in normal control group were injected with normal saline via the tail vein. The rats in the other groups were uninephrectomized and injected with adriamycin 5 mg/kg via the tail vein one week later. Rats in model group underwent gavage to receive the sodium carboxymethylcellulose, rats in irbesartan treatment group to receive the irbesartan with 10 mg/kg x d, and rats in tranilast treatment group to receive the tranilast with 400 mg/kg. Rats were then sacrificed at the end of week 8. The body weight, 24 hours urinary protein, blood urea nitrogen (BUN) and serum creatinine (Scr) of each group rats were measured for the study. Renal pathological changes were evaluated. And immunohistochemistry was used to examine the expression of transforming growth factor beta1 (TGF-beta1) and tissue inhibitor of metalloproteinase 1 (TIMP-1). In situ hybridization was used to measure the expression of a-smooth muscle actin (alpha-SMA) mRNA in the kidney. RESULTS: Compared with the untreated nephrotic syndrome rats, the proteinuria and Scr of rats treated with tranilast were significantly reduced (P < 0.05); Compared with model group, the renal pathological changes of rats in tranilast treatment group were decreased, with glomerular sclerosis to be markedly lower; Tranilast could decrease the expression of TGF-beta1, TIMP-1 and alpha-SMA mRNA in the kidney of rats with adriamycin nephropathy. CONCLUSIONS: Tranilast has a renoprotective effect on adriamycin-induced nephrotic syndrome in rats, of which the mechanism may be related to that tranilast can depress the expression of TGF-beta1, and TIMP-1 in the kidney, with result in decreasing the synthesis and secretion of extracellular matrix. And tranilast inhibits the transdifferentation of renal primary cells, regulates the synthesis and degradation system of extracellular matrix.