Joasoo A, Murray I P
Acta Endocrinol (Copenh). 1975 Jun;79(2):259-65. doi: 10.1530/acta.0.0790259.
The adrenergic receptors mediating the inhibitory effect of epinephrine on the rat thyroid in vivo have been studied by the use of more specific alpha- and beta-adrenergic stimulators, and blocking agents. The effect of methoxamine was similar to that of epinephrine, while isoproterenol stimulated 131-I uptake slightly, and did not alter the ratio of monoiodotyrosine (MIT) to diiodotyrosine (DIT). However, like methoxamine, isoproterenol resulted in a decrease in thyroxine (T4) formation. Phentolamine could partially prevent epinephrine-induced decrease in 131-I uptake and T4 synthesis. The changes in the MIT/DIT ratio could be completely prevented by high doses of phentolamine. Propranolol enhanced the effects of epinephrine. It is concluded that the effect of epinephrine on the rat thyroid in vivo is predominantly alpha-adrenergic, but T4 synthesis may be decreased by stimulation of either receptor.
通过使用更具特异性的α-和β-肾上腺素能刺激剂及阻断剂，对介导肾上腺素在体内对大鼠甲状腺抑制作用的肾上腺素能受体进行了研究。甲氧明的作用与肾上腺素相似，而异丙肾上腺素轻微刺激了131-I摄取，且未改变一碘酪氨酸（MIT）与二碘酪氨酸（DIT）的比例。然而，与甲氧明一样，异丙肾上腺素导致甲状腺素（T4）生成减少。酚妥拉明可部分预防肾上腺素引起的131-I摄取和T4合成减少。高剂量酚妥拉明可完全预防MIT/DIT比例的变化。普萘洛尔增强了肾上腺素的作用。得出的结论是，肾上腺素在体内对大鼠甲状腺的作用主要是α-肾上腺素能的，但刺激任一受体都可能使T4合成减少。
