title: Aged kidneys are refractory to ischemic postconditioning in a rat model.
abstract: BACKGROUND
  Ischemic postconditioning (IPoC) is defined as a series of intermittent interruptions of blood flow in the early phase of reperfusion that mechanically alters the hydrodynamics of reperfusion and it attenuates renal damage after ischemia/reperfusion (I/R) injury in vivo. But all of these data had been obtained in adult populations and whether this protection was maintained in aging kidneys was unknown. The objective of this study was to establish whether the efficacy of IPoC is maintained in aging kidneys.
  
  
  METHODS
  The aged (24-month-old) and young (3-month-old) Wistar rats were used. Rats were subjected to 45 min of renal ischemia, both with and without treatment with IPoC. Serum urea nitrogen and creatinine levels, histological examination and apoptosis were assessed at 24 h. Oxidative stress was evaluated and apoptosis-related molecules were studied by Western blotting.
  
  
  RESULTS
  In young rat kidneys, IPoC significantly attenuated the renal dysfunction and cell apoptosis induced by I/R. In contrast, IPoC failed to limit renal dysfunction, possibly a consequence of increased apoptosis in aged rat kidneys.
  
  
  CONCLUSIONS
  Our data indicated that IPoC was ineffective in aged rat kidneys. These findings may have major implications in that severe apoptosis in aged kidneys might be refractory to anti-apoptotic effect by IPoC.
authors.affiliation: Department of Urology, Renmin Hospital of Wuhan University , Wuhan , China and.
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Bianzhi
authors.initials: B
authors.lastname: Xing
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Weng
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Chen
authors.forename: Xiuheng
authors.initials: X
authors.lastname: Liu
mesh_terms: D058186:Acute Kidney Injury / Q000517:prevention & control*; D000375:Aging / Q000473:pathology / Q000502:physiology*; D000818:Animals; D017209:Apoptosis; D004195:Disease Models, Animal; D057775:Ischemic Postconditioning; D007668:Kidney / Q000098:blood supply / Q000473:pathology / Q000502:physiology*; D008297:Male; D018384:Oxidative Stress; D011897:Random Allocation; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000517:prevention & control*; D017211:Treatment Failure
keywords: Aged rats; ischemia/reperfusion; ischemic postconditioning; kidney