Melatonin MT sub(1) and MT sub(2) Receptors in the Ram Reproductive Tract

• Published in: International journal of molecular sciences 2017-03, Vol.18 (3), p.662-662
• Main Authors: Gonzalez-Arto, Marta, Aguilar, David, Gaspar-Torrubia, Elena, Gallego, Margarita, Carvajal-Serna, Melissa, Herrera-Marcos, Luis V, Serrano-Blesa, Edith, Hamilton, Thais Rose dos Santos, Perez-Pe, Rosaura, Muino-Blanco, Teresa, Cebrian-Perez, Jose A, Casao, Adriana
• Format: Article
• Language: English
• ISSN: 1422-0067
• DOI: 10.3390/ijms18030662

Some melatonin functions in mammals are exerted through MT sub(1) and MT sub(2) receptors. However, there are no reports of their presence in the reproductive tract of the ram, a seasonal species. Thus, we have investigated their existence in the ram testis, epididymis, accessory glands and ductus deferens. Real-time polymerase chain reaction (qPCR) revealed higher levels of m-RNA for both receptors in the testis, ampulla, seminal vesicles, and vas deferens, than in the other organs of the reproductive tract (p< 0.05). Western blot analyses showed protein bands compatible with the MT sub(1) in the testis and cauda epididymis, and for the MT sub(2) in the cauda epididymis and deferent duct. Immunohistochemistry analyses revealed the presence of MT sub(1) receptors in spermatogonias, spermatocytes, and spermatids, and MT sub(2) receptors in the newly-formed spermatozoa in the testis, whereas both receptors were located in the epithelial cells of the ampulla, seminal vesicles, and ductus deferens. Indirect immunofluorescence showed significant differences in the immunolocation of both receptors in spermatozoa during their transit in the epididymis. In conclusion, it was demonstrated that melatonin receptors are present in the ram reproductive tract. These results open the way for new studies on the molecular mechanism of melatonin and the biological significance of its receptors.