Induction of type II 5'-deiodinase activity by cyclic adenosine 3', 5'-monophosphate in cultured rat astroglial cells.
Cultured astroglial cells were found to contain a type II 5'-deiodinase (5'D) activity which was increased by 10(-3) M (Bu)2cAMP but not by 2 X 10(-3) M n-butyrate. 8-Bromo-cAMP (8-Br-cAMP) (10(-3) M) also increased this enzyme activity. Cycloheximide (2 micrograms/ml) inhibited the 8-Br-cAMP effect on 5'D activity. Forskolin (10(-5) M), cholera toxin (5 micrograms/ml), 10(-5) M isoproterenol, and 3 X 10(-6) M norephinephrine also increased the 5'D activity of astroglial cells. After a 4-h incubation these agents or cAMP analogs had maximal effect, and enzyme activities were 6- to 14-fold above control value. The stimulatory effects of isoproterenol and norepinephrine were almost completely reversed after 8 h incubation. The induction of 5'D activity by isoproterenol or norepinephrine was inhibited by the beta-adrenergic antagonist alprenolol (5 X 10(-6) M). The effect of norepinephrine was not significantly affected by the alpha 1-adrenergic antagonist, prazosin (10(-5) M). Thus, 5'D activity is controlled by agents increasing cAMP in astroglial cells, and in particular by the neurotransmitter, norephinephrine, via a beta-adrenergic mechanism.
Courtin
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F
Unité de Recherche sur la Glande Thyroïde et la Régulation Hormonale, U.96 Institut National de la Santé et de la Recherche Médicale, Hôpital de Bicétre, Le Kremlin-Bicêtre, France.
Chantoux
F
F
Pierre
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Francon
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J
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000201:enzymology*; D001921:Brain / Q000201:enzymology; D003994:Bucladesine / Q000494:pharmacology; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000502:physiology*; D003513:Cycloheximide / Q000494:pharmacology; D004790:Enzyme Induction; D007453:Iodide Peroxidase / Q000096:biosynthesis*; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats
D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate; D003994:Bucladesine; D003513:Cycloheximide; D000242:Cyclic AMP; D007453:Iodide Peroxidase; D007545:Isoproterenol; D009638:Norepinephrine