title: Ischemic postconditioning inhibits the renal fibrosis induced by ischemia-reperfusion injury in rats.
abstract: OBJECTIVE
  To investigate whether ischemic postconditioning effects on the development of tubulointerstitial fibrosis follow acute renal ischemia-reperfusion.
  
  
  METHODS
  Rat models of warm renal I/R were established by clamping left pedicles for 45 minutes after right nephrectomy, both with and without treatment with ischemic postconditioning, and then reperfused for up to 12 weeks. Hematoxylin-eosin (H&E) and Masson's trichrome staining were used to assess renal fibrosis. The expression spot and protein levels of α-smooth muscle actin (α-SMA), transforming growth factor-β1 (TGF-β1), and phospho-Smad2 were also analyzed.
  
  
  RESULTS
  Our data showed that patchy inflammation and tubulointerstitial fibrosis were found 12 weeks later in rats subjected to I/R alone or with postconditioning. Tubulointerstitial fibrosis worsened further in rats subjected to 45-minute ischemia-reperfusion, accompanied by the increased expressions of α-SMA, TGF-β1, and phospho-Smad2 at the end of 12 weeks. In contrast, the above histologic changes and molecular expressions were significantly attenuated in rats of ischemic postconditioning group.
  
  
  CONCLUSIONS
  The results indicated that 45-minute I/R injury may cause tubulointerstitial fibrosis in the long term, and ischemic postconditioning has beneficial effects on renal fibrosis. Its mechanisms may involve inhibition of the TGF-β1/phospho-Smad2 pathway to exert protective effects.
authors.affiliation: Department of Urology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Weng
authors.forename: Hao
authors.initials: H
authors.lastname: Shen
authors.forename: Youlin
authors.initials: Y
authors.lastname: Kuang
authors.forename: Xiuhen
authors.initials: X
authors.lastname: Liu
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Chen
authors.forename: Henchen
authors.initials: H
authors.lastname: Zhu
authors.forename: Botao
authors.initials: B
authors.lastname: Jiang
authors.forename: Guohui
authors.initials: G
authors.lastname: Zhu
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
mesh_terms: D000818:Animals; D005355:Fibrosis / Q000209:etiology / Q000517:prevention & control; D057775:Ischemic Postconditioning; D007668:Kidney / Q000098:blood supply* / Q000473:pathology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000150:complications*