Does HSP70 Induced by Amphetamine Prevent Renal Ischemia/Reperfusion Injury in Rat?

Jo, Young Il; Na, Heung Sik; Back, Seung Keun; Cho, Seung Che; Kim, Kyo Soon; Choi, Young Sook; Song, Jong Oh

Abstract

BACKGROUND
Heat shock proteins (HSPs) induced by variable kinds of stress produce tolerance to a variety of adverse conditions. However, the protective effect of HSP on ischemia/reperfusion injury (I/R injury) of kidney in vivo remains unclear. The present study was designed to evaluate whether HSP70 induced by hyperthermic preconditioning had renoprotective effect on I/R injury of the kidney in vivo. METHODS: 82 Sprague-Dawley male rats were used. Animals in control group (n=24) were subjected to bilateral occlusion of renal pedicles for 30 or 60 minutes followed by 24-hour reperfusion. In amphetamine (Amp, n=18) and quercetin (Q, n=16) group, amphetamine sulfate, a sympathomimetic drug which can elevate the body temperature as a result of enhanced endogenous lipolysis, and quercetin, a biflavonoid which inhibit the expression of HSP, were injected 4 hours prior to renal ischemia, respectively. In quercetin-amphetamine (QAmp, n=7) group, quercetin was injected 1 hour before administration of amphetamine. AA (n=8) or QQ (n=9) group was identical to Amp or Q group except that sham operation was performed instead of ischemic insult. In all groups, animals were sacrificed prior to or 24 hours after I/R injury. HSP70 induction was confirmed by immunohistochemistry. To assess the I/R injury of kidney, BUN, Cr, histopathologic change of tubular cell and HSP70 expression were evaluated. RESULTS: In Amp group, an increase of BUN and Cr were significantly lower than other groups and less severe renal tubular injury was also observed. In addition, HSP70 was strongly expressed in Amp group, whereas HSP70 was weakly expressed in control group and not expressed in QAmp and Q group. There were no differences in the functional and histologic injuries of kidney after I/R injury between AA, QQ and control group. CONCLUSION: These data demonstrate that the renoprotective effect by amphetamine preconditioning to I/R injury is linked with the expression of HSP70.