title: Nyctohemeral rhythmicity of type II thyroxine 5'-deiodinase activity in the pineal gland but not in the Harderian gland of the Swiss mouse.
abstract: Type II thyroxine 5'-deiodinase (5'-D) activity in both pineal and Harderian glands of the Swiss mouse was studied. Pineal 5'-D activity exhibited a nyctohemeral profile with a maximal peak value at 05.00 h, which coincides with that for pineal melatonin production. However, no rhythm of 5'-D activity in the Harderian gland could be found. In pineal gland, light at night inhibited the nocturnal increase in 5'-D activity, while isoproterenol, a beta-adrenergic agonist, could not stimulate the enzyme. In the Harderian gland, neither darkness, nor light or night, or isoproterenol were capable of modifying basal values of 5'-D activity.
authors.affiliation: University of Seville School of Medicine, Department of Medical Biochemistry and Molecular Biology, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Rubio
authors.forename: C
authors.initials: C
authors.lastname: Osuna
authors.forename: M A
authors.initials: MA
authors.lastname: Lopez-Gonzalez
authors.forename: R J
authors.initials: RJ
authors.lastname: Reiter
authors.forename: J M
authors.initials: JM
authors.lastname: Guerrero
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D003624:Darkness; D006243:Harderian Gland / Q000201:enzymology* / Q000378:metabolism; D007453:Iodide Peroxidase / Q000378:metabolism*; D007545:Isoproterenol / Q000494:pharmacology; D008027:Light; D008297:Male; D008550:Melatonin / Q000378:metabolism; D051379:Mice; D010870:Pineal Gland / Q000201:enzymology* / Q000378:metabolism
chemical_list: D007453:Iodide Peroxidase; D008550:Melatonin; D007545:Isoproterenol