title: Direct effects of the pineal hormone melatonin on testosterone synthesis of Leydig cells in Djungarian hamsters (Phodopus sungorus) in vitro.
abstract: Leydig cells of adult Djungarian hamsters, stimulated with luteinizing hormone (LH), were co-incubated with melatonin at various concentrations in a primary culture system. Testosterone secretion was only affected by melatonin when cells were stimulated with LH. Maximal suppression was observed at low doses of LH (0.5 ng/ml). These effects are at least partially mediated through the adenylate cyclase system, since melatonin was able to reduce forskolin-stimulated testosterone secretion. These results indicate that the time between pulses of LH can be considered to be most highly effective for tonic melatonin actions.
authors.affiliation: Institute of Reproductive Medicine of the University, Münster, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Niedziela
authors.forename: A
authors.initials: A
authors.lastname: Lerchl
authors.forename: E
authors.initials: E
authors.lastname: Nieschlag
mesh_terms: D000818:Animals; D005576:Colforsin / Q000494:pharmacology; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007985:Leydig Cells / Q000187:drug effects*; D007986:Luteinizing Hormone / Q000494:pharmacology; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D013739:Testosterone / Q000097:blood* / Q000378:metabolism*
chemical_list: D005576:Colforsin; D013739:Testosterone; D007986:Luteinizing Hormone; D008550:Melatonin