Renal ischemia-reperfusion (I/R) injury is a major cause of acute kidney injury via inflammation and cell apoptosis. Volatile anesthetics have been shown to exert organ-protective effects against kidney damage in vivo and in vitro. In the present study, we investigated the effects of isoflurane, a commonly used volatile anesthetic, on renal I/R injury and the underlying mechanisms. Rats subjected to renal I/R displayed higher serum creatinine and blood urea nitrogen levels than sham rats as well as severe histopathological damage. Renal I/R also resulted in a nuclear factor-κB (NF-κB)-mediated inflammatory response and dysfunction of the p53-Bax-caspase-3 apoptotic pathway. Rats preconditioned with 1.5% isoflurane for 2 h had better renal function and less tubular apoptosis 24 h after I/R injury than control rats. Pretreatment with isoflurane suppressed renal NF-κB activation, leading to a reduction in proinflammatory molecules (high-mobility group box 1, interleukin-1β, and tumor necrosis factor-α) both in the kidneys and circulation. In addition, rats subjected to isoflurane preconditioning had a higher Bcl-2/Bax ratio and less cleaved caspase-3. Our findings suggest that preconditioning with a clinically relevant concentration of isoflurane attenuates renal I/R injury, based at least in part on its ability to modulate renal inflammation and apoptosis.Key words acute kidney injury; ischemia-reperfusion; volatile anesthetic; inflammation; apoptosis Renal ischemic-reperfusion (I/R) injury is a major cause of acute kidney injury (AKI), which occurs in many clinical settings including shock, renal transplantation, and renal artery angioplasty.1) Renal I/R injury always implies a poor prognosis and no effective therapy is currently available. Although the underlying mechanisms for renal I/R injury have been extensively studied, the pathophysiologic process involving inflammation and cell apoptosis and its relationship to subsequent renal injury remain to be fully elucidated.Nuclear factor-κB (NF-κB) is one of the most critical transcription factors involved in many inflammatory conditions, including renal I/R injury. Activation of NF-κB is a critical step in the systemic and renal inflammatory response, which leads to the release of proinflammatory cytokines including high-mobility group box 1 (HMGB1), 2) interleukin-1β (IL-1β), 3) and tumor necrosis factor-α (TNF-α).4) It has also been observed that the p53-Bax-caspase-3 apoptotic pathway is involved in renal I/R injury. 4,5) P53 can induce the downregulation of anti-apoptotic Bcl-2 and the upregulation of pro-apoptotic Bax. A decrease in the Bcl-2/Bax ratio triggers cytochrome c release from mitochondria, which results in the activation of caspase-3 and a chain reaction leading to apoptosis.6,7) Therefore, inhibiting the coexisting processes of inflammation and apoptosis provides a potential approach to the prevention and treatment of renal I/R injury.Isoflurane is a volatile anesthetic commonly used in clinical surgical settings. Previous studies have indicated ...