Evidence that rat pineal thyroxine 5'-deiodinase is primarily stimulated by beta- and not alpha-adrenergic agonists and that its adrenergic-stimulated and spontaneous rhythmic nocturnal rise require RNA and protein synthesis.
Pineal thyroxine 5'-deiodinase (5'-D) activity rose greater than 10-fold above the basal level 2-3 hr after 1 mg/kg isoproterenol and returned to near the basal level by 6 hr. The same dose of norepinephrine or phenylephrine was without effect, but phenylephrine modestly potentiated isoproterenol-stimulated 5'-D activity. Either actinomycin D or cycloheximide treatment markedly decreased diurnal isoproterenol stimulation and the spontaneous rhythmic nocturnal rise of pineal 5'-D. The data indicate that pineal 5'-D activity is very similar to pineal serotonin N-acetyl transferase in being primarily stimulated by beta-adrenergic agonists and requiring new RNA and protein synthesis for its activation.
Murakami
M
M
Department of Medicine, Oregon Health Services University, Portland 97201.
Greer
M A
MA
Hjulstad
S
S
Greer
S E
SE
Tanaka
K
K
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D004347:Drug Interactions; D007453:Iodide Peroxidase / Q000378:metabolism*; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D010870:Pineal Gland / Q000187:drug effects / Q000201:enzymology*; D014176:Protein Biosynthesis; D012313:RNA / Q000096:biosynthesis*; D051381:Rats; D011919:Rats, Inbred Strains
D000316:Adrenergic alpha-Agonists; D000318:Adrenergic beta-Agonists; D003609:Dactinomycin; D010656:Phenylephrine; D012313:RNA; D003513:Cycloheximide; D007453:Iodide Peroxidase; D007545:Isoproterenol; D009638:Norepinephrine