title: Interferon-γ improves renal interstitial fibrosis and decreases intrarenal vascular resistance of hydronephrosis in an animal model.
abstract: OBJECTIVE
  To investigate the effect of interferon (IFN)-γ administration on renal interstitial fibrosis (RIF) and intrarenal vascular resistance of diseased kidneys in a reversible unilateral ureteral obstruction (RUUO) animal model.
  
  
  METHODS
  Thirty-six male Sprague-Dawley rats were randomly divided into three groups: RUUO with intramuscular IFN-γ treatment (400 IU/d; RUUO + IFN), RUUO with vehicle treatment, and sham operation. RUUO was induced by clamping the left ureter using a small polyethylene tube. The obstruction was reversed seven days after the operation by removing the tube. Six animals in each group were killed at days 7 and 14. The intrarenal resistive index (RI) of diseased kidneys was measured by colored Doppler flow imaging. RIF was evaluated using Masson's trichrome staining.
  
  
  RESULTS
  The obstruction was successfully reversed in all animals. At day 7, the RIF scores were 32.1 ± 3.1 and 40.3 ± 3.1 in the RUUO + IFN group and the RUUO group, respectively. The RI increased by 87% in the RUUO group and by 64% in the RUUO + IFN group compared with sham. At day 14, the RIF scores decreased to 24.6 ± 3.9 in the RUUO + IFN group, but increased to 50.8 ± 4.4 in the RUUO group. The increase of RI was reduced to 64% in the RUUO group and to 20% in the RUUO + IFN group. Ureteral obstruction induced few lesions in the contralateral kidneys, and IFN-γ administration had no significant effect on them, although it exerted an antifibrotic effect on the obstructed kidneys.
  
  
  CONCLUSIONS
  IFN-γ administration restored or preserved renal histology and hemodynamics in an animal model of renal fibrosis after surgical reversal of hydronephrosis.
authors.affiliation: Oncology Center, Renmin Hospital of Wuhan University, Wuhan, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yao
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Da-Qing
authors.initials: DQ
authors.lastname: Tan
authors.forename: Xiao-Yi
authors.initials: XY
authors.lastname: Chen
authors.forename: Da-Fu
authors.initials: DF
authors.lastname: Ye
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Peng
authors.forename: Jing-Tao
authors.initials: JT
authors.lastname: Li
authors.forename: Yi-Qun
authors.initials: YQ
authors.lastname: Zheng
authors.forename: Li
authors.initials: L
authors.lastname: Fang
authors.forename: You-Kong
authors.initials: YK
authors.lastname: Li
authors.forename: Ming-Xia
authors.initials: MX
authors.lastname: Fan
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D004195:Disease Models, Animal; D005355:Fibrosis; D006869:Hydronephrosis / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D007371:Interferon-gamma / Q000494:pharmacology*; D007668:Kidney / Q000187:drug effects / Q000473:pathology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012079:Renal Circulation / Q000187:drug effects*; D014517:Ureteral Obstruction / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D014655:Vascular Resistance / Q000187:drug effects*
chemical_list: D007371:Interferon-gamma