The inhibitory effect of noradrenaline on thyrotrophin-stimulated 3,5,3'-tri-iodothyronine and thyroxine release is mediated through a Ca(2+)-dependent process in the thyroid gland of the mouse.
We examined the effect of noradrenaline on the release of 3,5,3'-tri-iodothyronine (T3) and thyroxine (T4) from perifused mouse thyroid. Noradrenaline suppressed the thyrotrophin (TSH)-stimulated release of T3 and T4. The addition of prazosin, which is a specific alpha 1 antagonist, or the depletion of Ca2+ from the perifusion buffer completely abolished the inhibitory effect of noradrenaline on TSH-stimulated T3 and T4 release. Noradrenaline did not inhibit TSH-stimulated cyclic adenosine 3',5'-monophosphate (cAMP) release in the presence of 3-isobutyl-1-methylxanthine (IBMX), which inhibits both cAMP-specific and calmodulin-sensitive phosphodiesterases. Noradrenaline significantly suppressed the TSH-stimulated release of T3 and T4 in the presence of IBMX. These results suggest that the inhibitory effect of noradrenaline on TSH-stimulated T3 and T4 release is not mediated through a cAMP-dependent process or the activation of a calmodulin-sensitive phosphodiesterase, and that this inhibition is mediated through a Ca(2+)-dependent process regulated by the alpha 1-adrenergic system in the mouse thyroid.
Oda
Y
Y
Second Department of Internal Medicine, Osaka University Medical School, Japan.
Mashita
K
K
Mori-Tanaka
M
M
Kitajima
K
K
Miyagawa
J
J
Tajima
K
K
Hanafusa
T
T
Kono
N
N
Matsuzawa
Y
Y
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000502:physiology*; D002147:Calmodulin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009638:Norepinephrine / Q000494:pharmacology*; D010727:Phosphoric Diester Hydrolases / Q000502:physiology; D011224:Prazosin / Q000494:pharmacology; D013961:Thyroid Gland / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D013972:Thyrotropin / Q000494:pharmacology*; D013974:Thyroxine / Q000378:metabolism*; D014284:Triiodothyronine / Q000378:metabolism*
D002147:Calmodulin; D014284:Triiodothyronine; D013972:Thyrotropin; D000242:Cyclic AMP; D010727:Phosphoric Diester Hydrolases; D013974:Thyroxine; D002118:Calcium; D015056:1-Methyl-3-isobutylxanthine; D009638:Norepinephrine; D011224:Prazosin