大鼠肾间质纤维化动物模型的实验研究

Investigation of Renal Fibrosis Induced by Unilateral Ureteral Obstruction

目的 观察单侧输尿管结扎 (UUO)大鼠模型中肾脏病理改变 ,肾组织α 平滑肌肌动蛋白 (α SMA)和纤维连接蛋白 (FN)表达的变化 ,证明UUO方法可快速制作理想的肾脏细胞转分化和间质纤维化动物模型。方法 大鼠随机分为假手术组 (SOR)和UUO组。随机选取各组中的 6只大鼠分别于单侧输尿管结扎术后 3天、 7天、 14天、 2 1天和 2 8天处死 ,收集血清与肾组织供生化及病理分析。结果 ① 2 4小时尿蛋白定量 ,UUO组与假手术组无统计学差异。UUO术后 7～ 14天 ,大鼠出现明显血尿素氮、肌酐值升高 ;术后 2 1～ 2 8天 ,血尿素氮、肌酐值反而下降 ,但 2 8天时血肌酐值仍然高于假手术组 (P <0 0 5 )。②UUO组肾小管间质损伤评分 (TIS)明显高于假手术组。UUO术后 3天 ,肾脏组织出现了早期纤维化的病理改变。随着梗阻时间延长 ,小管间质纤维化程度和间质细胞增殖、炎细胞浸润逐渐加重 ,皮质变薄十分明显。术后 2 8天 ,Masson染色见皮质区、皮髓交界处纤维化明显 ,但肾小球仍无明显病变。③免疫组化结果显示 ,UUO术后 3天肾间质α SMA阳性细胞数和FN表达增加 ,并随时间递增。UUO术后 7天 ,可见少许α SMA阳性的转分化小管上皮细胞 ;术后14天转分化的小管上皮细胞明显增多。α SMA表达与FN表达成正相关 (r=0 996 ,P

Objective To prove renal tubulointerstitial fibrosis could be rapidly induced in rat by unilateral ureteral obstruction(UUO). Methods Rats were sacrificed at 3,7,14,21 and 28 days after UUO or Sham-surgery. The level of serum creatinine and 24-hour urine protein and renal histopathology at each time point were examined. Results The level of urine protein were not significantly higher in UUO group than in Sham-operation group. The level of serum creatinine and urea nitrogen increased progressively at day 7 and 14 after UUO,then gradually decreased at day 21 and 28 after UUO. At day 28,the serum creatinine was significantly higher in UUO group than in Sham-operation group(P<0.05). From day 3,the number of α-SMA-positive interstitial cells and tubulointerstitial expression of FN and inflammatory cell increased. TIS,the score of renal interstitial lesion and the expression of α-SMA and FN were significantly higher in UUO group than in Sham-operation group. There were significant correlations between the positive area of α-SMA and FN expression and the relative volume of interstitium and TIS. Conclusion Unilateral ureteral obstruction has emerged as an important model for the study of the mechanisms of renal fibrosis and transdifferentiation and also for the evaluation of the impact of potential therapeutic approaches to ameliorate renal disease.