CICS-UBI-Health Sciences Research Centre, Universidade da Beira Interior, Covilhã, Portugal.
Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
Adv Protein Chem Struct Biol. 2024;142:163-190. doi: 10.1016/bs.apcsb.2024.06.005. Epub 2024 Jul 4.
Melatonin is an indolamine secreted to circulation by the pineal gland according to a circadian rhythm. Melatonin levels are higher during nighttime, and the principal function of this hormone is to organize the temporal night and day distribution of physiological adaptive processes. Besides hormonal pineal production, melatonin is synthesized in various organs and tissues like the ovaries or the placenta for local utilization. In addition to its function as a circadian messenger, melatonin is also associated with many physiological functions. For example, melatonin has antioxidant properties and is involved in the regulation of energy and bone metabolism, and reproduction. Melatonin impacts several stages of reproduction and the action across the hypothalamus-pituitary-gonadal axis is well described. However, it is not well understood how those actions impact the female reproductive hormones secretion nor the consequent physiological outcomes. Thus, the first part of this chapter describes the regulation of female reproductive hormone synthesis by melatonin. Moreover, melatonin and female reproductive hormones have coincident physiological functions. Life stages like pregnancy or menopause are characterized by alterations in the reproductive hormones secretion that may be associated with certain physiological stages. Therefore, the second part discusses whether melatonin fluctuations could have an overlapping role with reproductive hormones in contributing to clinical outcomes associated with pregnancy and menopause.
褪黑素是由松果体根据昼夜节律分泌到循环系统中的一种吲哚胺。褪黑素水平在夜间较高，其主要功能是组织生理适应过程的时间昼夜分布。除了松果腺激素的产生外，褪黑素还在卵巢或胎盘等各种器官和组织中合成，用于局部利用。除了作为昼夜信使的功能外，褪黑素还与许多生理功能有关。例如，褪黑素具有抗氧化特性，参与能量和骨代谢以及生殖的调节。褪黑素影响生殖的几个阶段，其在下丘脑-垂体-性腺轴中的作用已得到很好的描述。然而，人们并不清楚这些作用如何影响女性生殖激素的分泌，也不清楚随之而来的生理后果。因此，本章的第一部分描述了褪黑素对女性生殖激素合成的调节。此外，褪黑素和女性生殖激素具有相同的生理功能。像怀孕或更年期这样的生命阶段的特点是生殖激素分泌的改变，这可能与某些生理阶段有关。因此，第二部分讨论了褪黑素波动是否可以与生殖激素重叠，以促进与怀孕和更年期相关的临床结果。
