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 Sprague–Dawley 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 μg/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.