Abstract: Objective To study the protective effect and mechanism of dexmedetomidine (DEX) on renal ischemia-reperfusion (I/R) injury in mice. Methods The mice were divided into sham group, siRNA+sham group, renal I/R group (conventional method), DEX+I/R group (25 μg/kg DEX, intraperitoneal injection), siRNA+I/R group and siRNA+DEX+I/R group; siRNA+sham group, siRNA+I/R group and siRNA+DEX+I/R group were injected 5×10⁹ TU/kg lentivirus-sirtuin3 (SIRT3) siRNA through tail vein 3 days before surgery. Renal function was measured by biochemical analyzer, renal histomorphology was observed by HE staining, renal tissue apoptosis was detected by Tunel staining, and the expression of SIRT3, cyclophilin D (Cyp D) and cytochrome C (Cyt C) were detected by Western blot. Results DEX reduced the renal pathological damage after I/R, up-regulate the expression of SIRT3 and down-regulated the expression of Cyt C and acetylated Cyp D (P＜0.05). Inhibition of SIRT3 attenuated the protective effect of DEX on kidney. Conclusions The role of DEX in alleviating renal I/R injury may be related to the up-regulation of SIRT3.

Key words: acute kidney injury, dexmedetomidine, mitochondrial damage, sirtuin 3