2007•Di-Si Junyi Daxue xuebaoRequires access
Effect of ischemic postconditioning on cells apoptosis and bcl-2 and bax gene expression in renal tissue after ischemia-reperfusion injury in rats
Jing Liu
Open publisher page 0 citations
Abstract
AIM:To investigate the effect of ischemic postconditioning on apoptosis of and the expression of bcl-2 and bax gene in renal tissue after transient ischemia-reperfusion (I/R) injury and its mechanism. METHODS: Eighteen male SD rats weighed 250-280 g were randomly allocated into 3 groups (n=6 in each group): sham operation group (S group); ischemia-reperfusion group (I/R group) and I/R+ischemic postconditioning group (IPo group). The rats were anesthetized with intraperitoneal chloral hydrate 300 mg/kg. Bilateral kidneys were exposed through midline incision and bilateral renal pedicels were occluded for 45 min with a traumatic mini-clamp then unclamped for 6 h. In S group, the kidneys were exposed but their pedicles were not clamped. In IPo group, 45 min ischemia was followed by three 10 s episodes of ischemia at 10 s intervals for reperfusion. The animals were killed at 6 h post reperfusion. Blood samples were taken from heart for determination of urea nitrogen (BUN) and serum creatinine(Cr) uric acid(UA) concentrations. Kidneys were removed immediately for determinating the expression of bcl-2 mRNA and bax mRNA by RT-PCR and for microscopic examination. The apoptosis in the nephridial tissue was assessed by using TUNEL method and apoptotic index (AI) was calculated. RESULTS: The Cr and BUN concentrations, the expression of Bax mRNA and the AI were significantly increased whereas the expression of bcl-2 mRNA and the bcl-2 mRNA/bax mRNA ratio were significantly decreased in I/R group as compared with S group (P 0.05). Microscopic examination showed edema, degeneration and necrosis of ischemia renal tubule endothelial cells, tubular ectasia, congestion, edema, and infiltration of neutrophils in I/R group. The BUN and serum Cr levels, the expression of bax mRNA and the apoptotic index (AI) were significantly lower whereas the expression of bcl-2 mRNA and the bcl-2 mRNA/bax mRNA ratio were significantly higer in IPo group than in I/R group (P0.05). CONCLUSION: IPo can inhibit apoptosis of nephridial tissue induced by acute I/R injury by up-regulating bcl-2 gene, down-regulating bax gene and heightening bcl-2 mRNA/bax mRNA ratio.