Continuous light exposure modifies the nocturnal increase in rat thymus type II thyroxine 5'-deiodinase.
In the present study we show that thymus type II thyroxine deiodinase activity exhibits a nyctohemeral profile, with basal values during the day and high values at night. This rhythmic character is dependent on neuroadrenergic input since exposure to continuous light at night completely abolished the nocturnal rise of the enzyme activity. However, treatment with isoproterenol under light exposure at night restored it.
Soutto
M
M
Department of Medical Biochemistry and Molecular Biology, School of Medicine, University of Sevilla, Spain.
Molinero
P
P
Guerrero
J M
JM
D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000818:Animals; D002940:Circadian Rhythm; D005260:Female; D007453:Iodide Peroxidase / Q000378:metabolism*; D007545:Isoproterenol / Q000494:pharmacology; D008027:Light; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013950:Thymus Gland / Q000201:enzymology*
D000318:Adrenergic beta-Agonists; D007453:Iodide Peroxidase; D007545:Isoproterenol