title: [The role of NO-dependent mechanisms in melatonin antioxidant activity during hepatic ischemia-reperfusion in rats].
abstract: The antioxidant effect of melatonin on the blood oxygen transport and prooxidant-antioxidant balance during with hepatic ischemia-reperfusion (HIR) with inhibited NO synthase function has been studied in male Wistar rats. The animals were divided into 4 groups: (1) control; (2) hepatic ischemia (Pringle m., 30 min) and reperfusion for 120 min (HIR, n = 9); (9) HIR with melatonin (10 mg/kg, i.p., 10 min before HIR, n = 9); and (4) same with NO inhibitor (L-NAME, 10 mg/kg) added 5 min before melatonin administration. The indices of blood oxygen transport (p50act, pCO2, pH, pO2, etc.) and prooxidant-antioxidant balance (Schiff bases, conjugated dienes, catalase, retinol, alpha-tocopherol) were measured in blood and liver. HIR in group 1 resulted in higher p50act in mixed venous blood and sever oxidative disturbances: rise of CD and SB, decrease of alpha-T, Ret, and Cat. Melatonin in group 3 significantly improved these changes in p50act and prooxidant-antioxidant balance during HIR, but L-NAME in group 4 partly eliminated this effect. It is concluded that the antioxidant effect of melatonin during HIR is partly associated with NO-depended mechanisms, which can modify blood hemoglobin affinity to oxygen, thus limiting oxygen binding in free-radical processes.
authors.forename: M N
authors.initials: MN
authors.lastname: Khodosovskiĭ
authors.forename: V V
authors.initials: VV
authors.lastname: Zinchuk
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002374:Catalase / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects; D010100:Oxygen / Q000097:blood; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism; D015427:Reperfusion Injury / Q000378:metabolism / Q000517:prevention & control*; D014801:Vitamin A / Q000378:metabolism; D024502:alpha-Tocopherol / Q000378:metabolism
chemical_list: D000975:Antioxidants; D006454:Hemoglobins; D017382:Reactive Oxygen Species; D014801:Vitamin A; D009569:Nitric Oxide; D002374:Catalase; D019001:Nitric Oxide Synthase; D024502:alpha-Tocopherol; D008550:Melatonin; D010100:Oxygen; D019331:NG-Nitroarginine Methyl Ester