Abstract:

Objective To investigate the expressions of urotensin Ⅱ(UⅡ) and tissue transglutaminase (tTG) in rat renal fibrosis tissue and their significances,and provide experimental basis for further study on the mechanism of UⅡ-indced fibrosis. Methods The male Wistar rats were randomly divided into sham operation group (n=8) and model group (n=8).The models were established by unilateral ureteral obstruction (UUO) method.The rats were sacrificed at day 14.The  histological changes in renal tubular interstitium were observed by HE and Masson staining,and the mRNA and protein levels of UⅡ,tTG and fibronectin (FN) were detected by RT-PCR and immunohistochemistry. Results  The Masson and HE staining results showed  interstitial widening and obvious proliferation of collagen fibers in model group.The immunohistochemistry results showed weak signals of UⅡ,tTG and FN in renal tubular cells and tubulointerstitium,and very rare positive signals except UⅡin the glomeruli in sham operation group.Compared with sham opation group,the expressions of UⅡ,tTG and FN in model group were significantly increased (P<0.01) and the level of UⅡ protein had positive correlation with the level of FN protein（r=0.724,P<0.05）. The levels of UⅡ mRNA and protein had positive correlation with the levels oftTG mRNA（r=0.647,P<0.05） and protein（r=0.787,P<0.01）.Conclusion Both UⅡand tTG may play an important  role in the pathogensis of renal tubulointerstitial fibrosis,andUⅡmay promote the development of fibrosis partially via activation of tTG.

Key words: urotensin Ⅱ;tissue transglutaminase;unilateral ureteral obstruction;renal fibrosis