螺内酯对单侧输尿管梗阻大鼠肾间质纤维化程度的影响

Effect of spironolactone on renal interstitial fibrosis in rats with unilateral ureteral occlusion

目的探讨螺内酯在单侧输尿管梗阻大鼠肾间质纤维化中的作用。方法 25只Wistar大鼠随机分为模型组10只,螺内酯组10只,对照组5只。模型组、螺内酯组行右侧输尿管结扎术建立单侧输尿管梗阻模型,对照组不行手术。螺内酯组术前2 d及术后将螺内酯20 mg/kg用2 mL蒸馏水溶解后灌胃,模型组、对照组给予等量蒸馏水灌胃,均1次/d,至处死。模型组、螺内酯组分别于灌胃第14、21天各处死5只大鼠,对照组5只于灌胃第21天处死,取肾组织行Masson染色观察肾间质纤维化程度;采用免疫组织化学法测定Daintain、碱性成纤维细胞生长因子(basic fibroblast growth factor, bFGF)及纤连蛋白(fibronection, FN)表达;比较灌胃第21天3组Daintain、bFGF、FN表达的光密度(optical density, OD)值。结果对照组大鼠肾脏肾小管结构正常,排列整齐,肾间质无增宽及炎症细胞浸润;模型组大鼠出现肾间质纤维化,随造模时间延长,纤维化程度增加;螺内酯组大鼠肾间质纤维化程度较同期模型组减轻。对照组大鼠肾小球及肾小管上皮细胞质中有少量Daintain表达,肾小管上皮细胞质中有少量bFGF、FN表达;模型组灌胃第14、21天肾小球及肾小管上皮细胞质中Daintain、bFGF、FN表达均高于对照组和螺内酯组。灌胃第21天,模型组Daintain、bFGF、FN表达OD值(0.152 0±0.028 4、0.149 2±0.012 6、0.257 1±0.064 9)高于对照组(0.077 2±0.011 9、0.098 1±0.013 1、0.115 5±0.014 0)和螺内酯组(0.086 0±0.013 5、0.073 1±0.013 5、0.132 0±0.017 4)(P<0.05)。结论螺内酯通过降低Daintain、bFGF、FN表达,减轻单侧输尿管梗阻大鼠肾间质纤维化程度。

Objective To investigate the role of spironolactone in renal interstitial fibrosis in rats with unilateral ureteral occlusion. Methods Wistar rats were randomly divided into model group(n=10), spironolactone group(n=10) and control group(n=5). Model group and spironolactone group underwent right ureteral ligation to establish unilateral ureteral occlusion model, while control group received no surgery. Spironolactone group was gavaged with 20 mg/kg of spironolactone dissolved in 2 mL of distilled water 2 days before and after surgery, while model group and control group were gavaged with the same volume of distilled water, once a day, till the rats were sacrificed. Five rats in model group and spironolactone group were sacrificed on the 14 th and 21 st days after gavage, respectively, and 5 rats in control group was sacrificed on the 21 st day after gavage. The kidney tissues were taken for Masson staining to observe the degree of renal interstitial fibrosis. The expressions of Daintain, basic fibroblast growth factor(bFGF) and fibronectin(fibronection, FN) were determined by immunohistochemistry, and the optical density(OD) values of Daintain, bFGF and FN on the 21 st day after gavage were compared in three groups. Results The kidney tubules in control group were normal in structure and neatly arranged, and the renal interstitium showed no widened or inflammatory cell infiltration. Model group was found renal interstitial fibrosis, and the degree of fibrosis increased with the prolonged modeling time. Spironolactone group was found alleviated renal interstitial fibrosis compared with model group. There was a small amount of Daintain expression in the cytoplasm of glomerulus and tubular epithelial cells, and a small amount of bFGF and FN expressions in the cytoplasm of renal tubular epithelial cells in control group. The expressions of Daintain, bFGF and FN in the cytoplasm were higher in model group than those in control group and spironolactone group on the 14 th and 21 st days after gavage. On the 21 st day after gavage, the OD values of Daintain, bFGF and FN were higher in model group(0.152 0±0.028 4, 0.149 2±0.012 6, 0.257 1±0.064 9) than those in control group(0.077 2±0.011 9, 0.098 1±0.013 1, 0.115 5±0.014 0) and spironolactone group(0.086 0±0.013 5, 0.073 1±0.013 5, 0.132 0±0.017 4)(P<0.05). Conclusion Spironolactone can alleviate renal interstitial fibrosis in rats after unilateral ureteral occlusion by reducing the expressions of Daintain, bFGF and FN.