title: DHEA-sulfate causes a phase-dependent increase in melatonin secretion: a study of perifused rat pineal glands.
abstract: Steroid hormones affect various metabolic activities, including melatonin synthesis, in mammals and nonmammals. We report here the effects of dehydroepiandrosterone (DHEA) and DHEA-sulfate (DHEA-S), two steroids with weak androgen potency, on the levels of isoproterenol-stimulated melatonin released by perifused rat pineal glands removed in the middle of the light and dark spans [7 and 19 Hours After Light Onset (HALO), respectively] in a L/D 12:12 regimen. DHEA-S but not DHEA was found to have a direct action on beta-adrenergic-stimulated melatonin release. DHEA-S increased melatonin secretion (by 50-80%) dose-dependently in pineals obtained during the light span. This effect depended on the circadian stage, because at night (19 HALO), only the highest concentration (10(-3) M) of DHEA-S increased melatonin secretion (by 25%). In contrast, DHEA had no effect on melatonin release in pineals obtained during the light span. This work shows that DHEA-S but not DHEA was able to stimulate melatonin secretion by adrenergic-stimulated pineals removed during the light phase. It also suggests that the effects observed, or their intensity, or both depend on the circadian stage.
authors.affiliation: Department of Biochemistry, Faculty of Medicine Pitie-Salpetriere, 91 boulevard de l'hôpital, 75013, Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: San Martin
authors.forename: Y
authors.initials: Y
authors.lastname: Touitou
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology; D003687:Dehydroepiandrosterone / Q000494:pharmacology; D019314:Dehydroepiandrosterone Sulfate / Q000494:pharmacology*; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008550:Melatonin / Q000378:metabolism*; D010477:Perfusion; D010870:Pineal Gland / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000318:Adrenergic beta-Agonists; D003687:Dehydroepiandrosterone; D019314:Dehydroepiandrosterone Sulfate; D008550:Melatonin; D007545:Isoproterenol