Effect of melatonin on production of hydroxyl radical and lactate dehydrogenase during hypoxia in rat cortical slices

Effect of melatonin on production of hydroxyl radical and lactate dehydrogenase during hypoxia in rat cortical slices 1

目的：研究褪黑激素对大鼠大脑皮层脑片在缺氧后羟自由基及乳酸脱氢酶生成的影响．方法：通过水杨酸捕获法来观察缺氧再给氧中羟自由基含量的变化．脑片通以９１６％Ｎ２＋８４％Ｏ２造成缺氧．ＬＤＨ用细胞毒检测盒测定．结果：ＤＨＢＡ水平在缺氧及再给氧后显著升高；缺氧时给予褪黑激素可以浓度依赖性地降低再给氧１５ｍｉｎ时ＤＨＢＡ的含量，但对缺氧３０ｍｉｎ时ＤＨＢＡ的含量没有显著作用．ＬＤＨ的含量在缺氧后１ｈ内持续升高；褪黑激素可以显著降低缺氧后ＬＤＨ的释放．结论：褪黑激素降低大鼠缺氧后的损伤以及羟自由基的产生．

AIM: To study the effect of melatonin on the production of hydroxyl radical (·OH) and lactate dehydrogenase (LDH) following hypoxia in cortical slice. METHODS: Cortical slice was incubated with artificial cerebrospinal fluid (ACSF) in tube. Hypoxia was achieved by substituting 91 6 % N 2 and 8 4 % O 2. The salicylate trapping method was used to measure hydroxyl radicals generated. The content of LDH in medium after hypoxia was measured by International Federation of Clinic Chemistry (IFCC) method. RESULTS: The contents of dihydroxybenzoic acid (DHBA) were increased significantly during hypoxia and reoxygenation in cortical slice. The production of DHBA in reoxygenation was decreased concentration dependently by melatonin, but not during hypoxia 30 min. The release of LDH during hypoxia was steadily elevated and melatonin decreased the content of LDH after hypoxia. CONCLU￣SION: Melatonin decreased the injury and production of ·OH after hypoxia.