title: Development of the circadian melatonin rhythm and its responsiveness to PACAP in the embryonic chicken pineal gland.
abstract: The embryonic development of the circadian melatonin (MT) rhythm and the responsiveness of embryonic MT secretion to pituitary adenylate cyclase-activating polypeptide (PACAP) were investigated. Using dynamic in vitro bioassays, we showed the following: (1) The circadian clock and/or the intracellular signal transduction pathways connecting the clock to the MT synthesizing apparatus appear between days 16 and 18 (E16-18) of embryonic development. Lack of periodical environmental stimuli can lead to a delay in this maturation. (2) Exposure of the embryonic chicken pineal gland to PACAP induces a transitory increase in MT secretion and (3) a transitory increase in cyclic AMP efflux at or before day E13 in vitro.
authors.affiliation: Department of Anatomy, University of Pécs Medical School, and the Neurohumoral Regulations Research Group of the Hungarian Academy of Sciences, Hungary.
authors.forename: N
authors.initials: N
authors.lastname: Faluhelyi
authors.forename: D
authors.initials: D
authors.lastname: Reglodi
authors.forename: V
authors.initials: V
authors.lastname: Csernus
mesh_terms: D000818:Animals; D002642:Chick Embryo; D002940:Circadian Rhythm / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D008550:Melatonin / Q000378:metabolism*; D010870:Pineal Gland / Q000187:drug effects / Q000196:embryology* / Q000378:metabolism*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide / Q000494:pharmacology / Q000502:physiology*
chemical_list: D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D008550:Melatonin