title: Long-term effects of constant light or darkness on chicken pineal hydroxyindole-O-methyltransferase expression: biochemical and cellular aspects.
abstract: 1. Chickens kept in constant light, as opposed to constant darkness, display a twofold increase in the activity of pineal hydroxyindole-O-methyltransferase (HIOMT), the last acting enzyme in the melatonin pathway. 2. Using an immunological approach, we presently show that this regulation of HIOMT activity reflects changes in the concentration of a single molecular form of the enzyme protein (a 38 kDa polypeptide). Immunohistofluorescence indicates that these concentration changes concurrently affect modified photoreceptors and pinealocyte-like cells in the chicken pineal organ. 3. Together, the present data support the hypothesis that environmental lighting might regulate the expression of the HIOMT gene.
authors.affiliation: Laboratoire de Neurobiologie, URA CNRS No. 290, Poitiers, France.
authors.forename: J
authors.initials: J
authors.lastname: Guerlotté
authors.forename: P
authors.initials: P
authors.lastname: Voisin
authors.forename: M
authors.initials: M
authors.lastname: Bernard
authors.forename: P
authors.initials: P
authors.lastname: Brisson
authors.forename: J
authors.initials: J
authors.lastname: Falcón
authors.forename: J L
authors.initials: JL
authors.lastname: Blasquez
authors.forename: J P
authors.initials: JP
authors.lastname: Collin
mesh_terms: D000121:Acetylserotonin O-Methyltransferase / Q000096:biosynthesis* / Q000235:genetics; D000818:Animals; D002645:Chickens / Q000502:physiology*; D002940:Circadian Rhythm; D003624:Darkness; D004790:Enzyme Induction / Q000528:radiation effects; D008027:Light; D008550:Melatonin / Q000096:biosynthesis; D010786:Photoreceptor Cells / Q000201:enzymology / Q000528:radiation effects; D010870:Pineal Gland / Q000166:cytology / Q000201:enzymology / Q000528:radiation effects*
chemical_list: D000121:Acetylserotonin O-Methyltransferase; D008550:Melatonin