title: Melatonin-enhanced hyperactivation of hamster sperm.
abstract: The effects of melatonin on reproductive function were examined using hamster spermatozoa. When 1 pM to 1 microM melatonin was added to the mTALP medium, hyperactivation was significantly enhanced. Antagonists and agonists of the melatonin receptor (i.e., MT1 and MT2) were added to the medium. Luzindole, an MT1 and MT2 competitive antagonist, significantly inhibited melatonin-induced hyperactivation, whereas the MT2-specific antagonists, 4-phenyl-2-propionamidotetralin and N-pentanoyl-2-benzyltryptamine, had no effect. Moreover, hyperactivation was significantly enhanced when non-specific agonists, such as 6-chloromelatonin and 2-iodomelatonin, were added to the medium. 8-Methoxy-2-propionamidotetralin, which is a strong MT2 agonist and a weak MT1 agonist, significantly increased hyperactivation, although the effect was weak. Therefore, it is likely that melatonin enhances sperm hyperactivation via the MT1 receptor.
authors: Department of Physiology, School of Medicine, Dokkyo Medical University, Mibu, Tochigi 321-0293, Japan. fujinoki@dokkyomed.ac.jp
authors: Masakatsu
authors: M
authors: Fujinoki
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002478:Cells, Cultured; D006224:Cricetinae; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives / Q000494:pharmacology*; D008647:Mesocricetus; D044122:Receptor, Melatonin, MT1 / Q000819:agonists / Q000037:antagonists & inhibitors; D044123:Receptor, Melatonin, MT2 / Q000819:agonists / Q000037:antagonists & inhibitors; D012709:Serum Albumin / Q000494:pharmacology; D013081:Sperm Motility / Q000187:drug effects*; D013094:Spermatozoa / Q000187:drug effects*; D013268:Stimulation, Chemical; D013764:Tetrahydronaphthalenes / Q000494:pharmacology; D013995:Time; D014363:Tryptamines / Q000494:pharmacology
chemical_list: C114459:4-phenyl-2-propionamidotetraline; C533877:8-methoxy-2-propionamidotetralin; D003470:Culture Media; C408803:N-pentanoyl-2-benzyltryptamine; D044122:Receptor, Melatonin, MT1; D044123:Receptor, Melatonin, MT2; D012709:Serum Albumin; D013764:Tetrahydronaphthalenes; D014363:Tryptamines; C057154:luzindole; C024100:6-chloromelatonin; C044556:2-iodomelatonin; D008550:Melatonin; D002118:Calcium