Izzo Gaia, Francesco Aniello, Ferrara Diana, Campitiello Maria Rosaria, Serino Ismene, Minucci Sergio, d'Istria Michela
Dipartimento di Medicina Sperimentale-Sezione di Fisiologia Umana e Funzioni Biologiche Integrate F. Bottazzi, Seconda Università degli Studi di Napoli, 80138 Napoli, Italy.
Zygote. 2010 Aug;18(3):257-64. doi: 10.1017/S0967199409990293. Epub 2010 Jan 29.
It is well known that melatonin provokes reproductive alterations in response to changes in hours of daylight in seasonally breeding mammals, exerting a regulatory role at different levels of the hypothalamic-pituitary-gonadal axis. Although it has also been demonstrated that melatonin may affect testicular activity in vertebrates, until now, very few data support the hypothesis of a local action of melatonin in the male gonads. The aim of this study was to investigate whether MT1, MT2 melatonin receptors and the H9 melatonin-related receptor, are expressed in the adult rat testes and during development. A semi-quantitative RT-PCR method was used to analyse the expression of MT1, MT2 and H9 receptors mRNAs in several rat tissues, mainly focusing on testes during development and adult life. Our results provide molecular evidences of the presence of both MT1 and, for the first time, MT2 melatonin receptors as well as of the H9 melatonin-related receptor in the examined tissues, including adult testes. During development MT1 and MT2 transcripts are expressed at lower levels in testes of rats from 1 day to 1 week of age, lightly increased at 2 weeks of age and remained permanently expressed throughout development until 6 months. These data strongly support the hypothesis that melatonin acts directly in male vertebrate gonads suggesting that rat testes may be a suitable model to verify the role of indolamine in vertebrate testicular activity.
众所周知，褪黑素会引发季节性繁殖哺乳动物对日照时长变化做出生殖改变，在下丘脑 - 垂体 - 性腺轴的不同水平发挥调节作用。尽管也已证明褪黑素可能影响脊椎动物的睾丸活动，但到目前为止，很少有数据支持褪黑素在雄性性腺中存在局部作用这一假说。本研究的目的是调查MT1、MT2褪黑素受体以及H9褪黑素相关受体在成年大鼠睾丸中以及发育过程中是否表达。采用半定量RT-PCR方法分析MT1、MT2和H9受体mRNA在几种大鼠组织中的表达，主要聚焦于发育过程中和成年期的睾丸。我们的结果提供了分子证据，证明在所检查的组织（包括成年睾丸）中存在MT1以及首次发现的MT2褪黑素受体以及H9褪黑素相关受体。在发育过程中，MT1和MT2转录本在1日龄至1周龄大鼠的睾丸中表达水平较低，在2周龄时略有增加，并在整个发育过程中一直表达直至6个月。这些数据有力地支持了褪黑素直接作用于雄性脊椎动物性腺的假说，表明大鼠睾丸可能是验证吲哚胺在脊椎动物睾丸活动中作用的合适模型。
