title: Expression of melatonin (MT1, MT2) and melatonin-related receptors in the adult rat testes and during development.
abstract: 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.
authors.affiliation: Dipartimento di Medicina Sperimentale-Sezione di Fisiologia Umana e Funzioni Biologiche Integrate F. Bottazzi, Seconda Università degli Studi di Napoli, 80138 Napoli, Italy.
authors.forename: Gaia
authors.initials: G
authors.lastname: Izzo
authors.forename: Aniello
authors.initials: A
authors.lastname: Francesco
authors.forename: Diana
authors.initials: D
authors.lastname: Ferrara
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Campitiello
authors.forename: Ismene
authors.initials: I
authors.lastname: Serino
authors.forename: Sergio
authors.initials: S
authors.lastname: Minucci
authors.forename: Michela
authors.initials: M
authors.lastname: d'Istria
mesh_terms: D000818:Animals; D018507:Gene Expression Regulation, Developmental; D008297:Male; D008550:Melatonin / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D044122:Receptor, Melatonin, MT1 / Q000235:genetics* / Q000378:metabolism; D044123:Receptor, Melatonin, MT2 / Q000235:genetics* / Q000378:metabolism; D013737:Testis / Q000196:embryology* / Q000254:growth & development
chemical_list: D012333:RNA, Messenger; D044122:Receptor, Melatonin, MT1; D044123:Receptor, Melatonin, MT2; D008550:Melatonin