Department of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Minamikogushi 1-1-1, Ube, 755-8505 Japan.
J Ovarian Res. 2012 Jan 26;5:5. doi: 10.1186/1757-2215-5-5.
Melatonin (N-acetyl-5-methoxytryptamine) is secreted during the dark hours at night by pineal gland, and it regulates a variety of important central and peripheral actions related to circadian rhythms and reproduction. It has been believed that melatonin regulates ovarian function by the regulation of gonadotropin release in the hypothalamus-pituitary gland axis via its specific receptors. In addition to the receptor mediated action, the discovery of melatonin as a direct free radical scavenger has greatly broadened the understanding of melatonin's mechanisms which benefit reproductive physiology. Higher concentrations of melatonin have been found in human preovulatory follicular fluid compared to serum, and there is growing evidence of the direct effects of melatonin on ovarian function especially oocyte maturation and embryo development. Many scientists have focused on the direct role of melatonin on oocyte maturation and embryo development as an anti-oxidant to reduce oxidative stress induced by reactive oxygen species, which are produced during ovulation process. The beneficial effects of melatonin administration on oocyte maturation and embryo development have been confirmed by in vitro and in vivo experiments in animals. This review also discusses the first application of melatonin to the clinical treatment of infertile women and confirms that melatonin administration reduces intrafollicular oxidative damage and increase fertilization rates. This review summarizes our recent works and new findings related to the reported beneficial effects of melatonin on reproductive physiology in its role as a reducer of oxidative stress, especially on oocyte maturation and embryo development.
褪黑素（N-乙酰-5-甲氧基色胺）由松果腺在夜间的黑暗时段分泌，它调节与昼夜节律和生殖相关的各种重要的中枢和外周作用。人们一直认为褪黑素通过其特定的受体调节下丘脑-垂体轴中的促性腺激素释放来调节卵巢功能。除了受体介导的作用外，褪黑素作为直接自由基清除剂的发现极大地拓宽了对其有益于生殖生理学的机制的理解。与血清相比，人排卵前卵泡液中发现褪黑素浓度更高，并且越来越多的证据表明褪黑素对卵巢功能，特别是卵母细胞成熟和胚胎发育有直接影响。许多科学家专注于褪黑素对卵母细胞成熟和胚胎发育的直接作用，作为一种抗氧化剂来减少由活性氧引起的氧化应激，活性氧在排卵过程中产生。在动物的体内和体外实验中已经证实了褪黑素给药对卵母细胞成熟和胚胎发育的有益作用。这篇综述还讨论了褪黑素在治疗不孕妇女的临床治疗中的首次应用，并证实褪黑素给药可减少卵泡内氧化损伤并提高受精率。这篇综述总结了我们最近的工作和与褪黑素作为抗氧化剂减少氧化应激的报告有益作用相关的新发现，特别是在卵母细胞成熟和胚胎发育方面。
