title: Testicular activity is restored by melatonin replacement after suprachiasmatic nucleus lesion or superior cervical ganglionectomy in mink.
abstract: Subcutaneous melatonin implants were inserted in mink subjected to natural (autumn) or experimental gonadostimulatory short-days (4L:20D), after lesion of the suprachiasmatic nucleus (SCNx) or after superior cervical ganglionectomy (SCGx). Gonad stimulation was assessed by measuring testicular volume and plasma testosterone level. In SCNx and SCGx animals, all measurements were indicative of sexual quiescence. In contrast, both SCNx and SCGx animals with melatonin, maintained in natural or experimental gonadostimulating short-days, showed an increase in testicular activity 2 months after melatonin implantation. Thus, melatonin (and pineal activity) is a prerequisite for the photoperiodic stimulation of reproductive activity, and the SCN is not necessarily the target site for melatonin action on the renewal of reproduction in the mink.
authors.affiliation: Pathologie de l'Oreille interne et Réhabilitation, INSERM, Faculté de Médecine Nord, Boulevard Pierre-Dramard, Marseille cedex 20, France. maurel.d@jean-roche.univ-mrs.fr
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Maurel
authors.forename: Mohamed Moncef
authors.initials: MM
authors.lastname: Ben Saad
authors.forename: Gisèle
authors.initials: G
authors.lastname: Roch
authors.forename: Philippe
authors.initials: P
authors.lastname: Siaud
mesh_terms: D000818:Animals; D003714:Denervation; D015171:Ganglionectomy; D008297:Male; D008550:Melatonin / Q000008:administration & dosage* / Q000502:physiology; D008907:Mink; D017440:Photoperiod; D010870:Pineal Gland / Q000502:physiology; D012098:Reproduction / Q000502:physiology; D012621:Seasons; D017783:Superior Cervical Ganglion / Q000502:physiology*; D013493:Suprachiasmatic Nucleus / Q000293:injuries / Q000502:physiology*; D013737:Testis / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology*; D013739:Testosterone / Q000097:blood
chemical_list: D013739:Testosterone; D008550:Melatonin