Change of Plasma Xanthine Oxidase Activity by Intermittent Hepatic Ischemia-Reperfusion. |
Seong Jo Ha, Jae Hoon Kim, Sung Sik Park, InKyeom Kim, Woonyi Baek, Dong Gun Lim |
1Departments of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Daegu, Korea. dglim@knu.ac.kr 2Departments of Pharmacology, School of Medicine, Kyungpook National University, Daegu, Korea. |
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Abstract |
BACKGROUND The pringle maneuver (PM), hepatic inflow occlusion, during hepatic surgery reduces intraoperative bleeding and blood transfusion requirement, but hepatic ischemia/reperfusion injury is inevitable. During ischemia, xanthine oxidoreductase is converted to xanthine oxidase (XO), which can serve as a critical source of reactive oxygen species (reduces O2 to O2 .-) that contribute to inflammatory signaling, ischemia-reperfusion injury, and an impaired vascular function. The purpose of the present study was to follow changes of XO activity and O2 .- production during hepatic surgery under PM. METHODS Eleven patients that underwent hepatectomy under intermittent PM were studied. Blood was withdrawn before PM, and 10 and 20 minutes after final reperfusion. Plasma XO activity was measured using a spectrophotometer after incubating plasma with/without xanthine for one-hour.
Superoxide (O2 -) production was followed by measuring by cytochrome c reduction by plasma XO. RESULTS After final reperfusion, plasma XO activity had increased four-fold (0.36 +/- 0.06 to 1.25 +/- 0.25 mU/ml) with a concomitant increase in O2 .- production (0.66 +/- 0.29 to 1.66 +/- 0.40microM/min). CONCLUSIONS Significantly more XO is released into the systemic circulation after intermittent PM, with subsequently increased O2 .- production. The significant contribution of XO to hepatic surgery under PM might be beneficially managed using an anesthetic with a known antioxidative effect. |
Key Words:
hepatectomy; ischemia-reperfusion; pringle maneuver; reactive oxygen species; superoxide; xanthine oxidase |
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