Ischemic Preconditioning Protects Against Hepatic Ischemia-Reperfusion Injury Under Propofol Anesthesia in Rats.

Background. Propofol is widely used in general anesthesia, and it has been reported to protect various organs against ischemia-reperfusion injury (IRI), including liver. To evaluate the hepatoprotective effects of ischemic preconditioning (IP) under propofol anesthesia, we investigated the possible underlying mechanisms in rats. Methods. Male SpragueeDawley rats were randomly assigned to 3 groups: sham group (n = 5), non-IP group (n = 9; 45 minutes of hepatic ischemia followed by 2 hours of reperfusion), and IP group (n = 9; IP applied as 10 minutes of hepatic ischemia followed by 15 minutes of reperfusion before 45 minutes of ischemia). Anesthesia was maintained with intravenous (IV) infusion of propofol (800 mg/kg/min). Liver enzymes, histopathological changes, and cytokine expression were examined. Results. The IP group showed significantly lower liver enzyme levels (aspartate aminotransferase, P =.045; alanine aminotransferase, P =.006) and reduced the histologic grades of hepatic injury 2 hours after reperfusion (P =.004) compared to the non-IP group. Lactate dehydrogenase activity (P <.001) and interleukin-6 mRNA levels were significantly higher in the non-IP group than in the sham and IP groups (P =.002, both groups). Conclusions. Our results demonstrate that IP under propofol anesthesia significantly attenuated hepatic IRI. The principal mechanism of the protective effects appeared to involve reduced expression of the IL-6 pro-inflammatory cytokine and subsequent reduction of the degree of necrosis.