Melatonin and female reproduction

Abstract

Melatonin (N-acetyl-5-methoxytryptamine) is secreted during the dark hours at night by the pineal gland. After entering the circulation, melatonin acts as an endocrine factor and a chemical messenger of light and darkness. It regulates a variety of important central and peripheral actions related to circadian rhythms and reproduction. It also affects the brain, immune, gastrointestinal, cardiovascular, renal, bone and endocrine functions and acts as an oncostatic and anti-aging molecule. Many of melatonin's actions are mediated through interactions with specific membrane-bound receptors expressed not only in the central nervous system, but also in peripheral tissues. Melatonin also acts through non-receptor-mediated mechanisms, for example serving as a scavenger for reactive oxygen species and reactive nitrogen species. At both physiological and pharmacological concentrations, melatonin attenuates and counteracts oxidative stress and regulates cellular metabolism. Growing scientific evidence of reproductive physiology supports the role of melatonin in human reproduction. This review was conducted to investigate the effects of melatonin on female reproduction and to summarize our findings in this field.

Melatonin actions on ovaprim (synthetic GnRH and domperidone)-induced oocyte maturation in carp

“…Likewise, a study on killifish (Lombardo et al 2012) provides evidence that endogenously synthesized or exogenously added melatonin acts on steroidogenesis by regulating steroidogenic enzyme activities in theca and granulosa cells of the ovary (Tamura et al 2009). Moreover, the discovery that melatonin due to its lipophilic nature can easily cross the plasma membrane of cells to act directly as a scavenger of free radicals (Tan et al 1993) followed by studies demonstrating the stimulation of antioxidative enzymes by melatonin (Rodriguez et al 2004) and even scavenging actions of its metabolites on free radicals (Galano et al 2013) added a new dimension to the current understanding on the physiological role of melatonin as a potent antioxidant (Zhang & Zhang 2014) in the regulation of ovarian functions in at least mammals (Tamura et al 2014).…”

“…Melatonin detected in the pre-ovulatory follicles seems to minimize oxidative stress and ultimately to improve the quality of oocytes (Tamura et al 2014). The information gathered from mammalian studies also reveals that melatonin acts on various cells of ovarian follicles as an indirect antioxidant to stimulate several antioxidative agents, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione transferase (GST) and reduced glutathione (GSH), which metabolize free radicals to reduce oxidative stress (Reiter 1996).…”

Chronobiological Aspects of Sleep Disorders in Menopausal Women: The Role of Melatonin (Literature Review)

“…При поиске гендерных раз-личий содержания мелатонина у людей в возрасте от 60 лет и старше выявлен более низкий его уровень у женщин [30], хотя в репродуктивном возрасте отме-чены противоположные результаты [13]. Возрастное снижение секреции мелатонина в женском организме сигнализирует о расстройстве пинеального и гипофи-зарного контроля над яичниковой цикличностью и о прогрессивном угасании фертильной функции жен-щины [40]. Результаты исследования, проведённого Л.И.…”

The role of melatonin in development of gestational diabetes mellitus

“…У лиц, имеющих патологию нейроиммуно-эндокринной системы и изначально низкую продукцию мелатонина, при адаптации орга-низма к беременности значительная активация свободнорадикального окисления ведет к исто-щению антиоксидантных резервов, и прежде всего мелатонина [67,68]. Не только низкий уровень мелатонина, но и нарушение в резуль-тате окислительной модификации белков функ-ционального состояния его рецепторов, обес-печивающих регуляцию продукции инсулина и глюкагона в β-и α-клетках поджелудочной ОБЗОРы / REVIEWS 88 железы, ведет к неконтролируемой секреции инсулина не только в дневное время суток, но и в ночные часы.…”