Preconditioning with 1,25-dihydroxyvitamin D₃ protects against subsequent ischemia-reperfusion injury in the rat kidney

Background/Aim: Induction of heat shock protein 70 (HSP70) is important in the tolerance of subsequent ischemia-reperfusion (I/R) injury. The aim of this study was to evaluate the effect of HSP70 induction by 1,25-dihydroxyvitamin D₃ (VD3) on subsequent I/R injury in rats. Methods: HSP70 was induced in Sprague-Dawley rats by VD3 treatment for 7 days, and the effect of VD3 pretreatment on subsequent I/R injury was evaluated in terms of renal function, tubular necrosis score, tumor necrosis factor alpha mRNA expression, mitogen-activated protein kinase expression, and proliferating cell nuclear antigen expression. Results: VD3 treatment increased HSP70 expression which was localized to renal tubular cells in the outer medulla. Pretreatment with VD3 before I/R injury resulted in (1) decreased blood urea nitrogen and serum creatinine levels; (2) decreased tubular cell necrosis; (3) increased tubular cell proliferation as determined by proliferating cell nuclear antigen expression; (4) decreased tumor necrosis factor alpha mRNA expression, and (5) increased extracellular signal regulated protein kinase and decreased c-Jun N-terminal kinase expression. Conclusion: Our study demonstrates that VD3 is a nontoxic inducer of HSP70 and exerts a protective effect against subsequent I/R injury.