Investigation of Renal Fibrosis Induced by Unilateral Ureteral Obstruction

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(P0.05). 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.