Corda D, Kohn L D
Biochem Biophys Res Commun. 1986 Dec 30;141(3):1000-6. doi: 10.1016/s0006-291x(86)80143-7.
The regulation of thyroid hormone formation by thyrotropin and norepinephrine involves the activation of both phospholipases C and A2. When FRTL-5 cells are incubated with 10(-10)M pertussis toxin for 4 to 20 h, the stimulation of iodide efflux by norepinephrine is inhibited by 50 to 70%. At the same toxin concentration the norepinephrine induced increase in cytosolic Ca2+ is unaffected; however upon 20 h pretreatment with 10(-9)M pertussis toxin a 30% inhibition is observed. By contrast, the pertussis toxin treatment had no effect on the increase in iodide efflux or in cytosolic Ca2+ levels induced by thyrotropin. Our data suggest that two GTP binding proteins sensitive to pertussis toxin are involved in the alpha 1 adrenergic but not in the thyrotropin induced activation of the signal transduction mechanisms leading to iodide efflux in FRTL-5 cells.
促甲状腺激素和去甲肾上腺素对甲状腺激素合成的调节涉及磷脂酶C和A2的激活。当FRTL-5细胞与10^(-10)M百日咳毒素孵育4至20小时时，去甲肾上腺素对碘外流的刺激作用被抑制50%至70%。在相同毒素浓度下，去甲肾上腺素诱导的胞质Ca2+增加不受影响；然而，用10^(-9)M百日咳毒素预处理20小时后，可观察到30%的抑制作用。相比之下，百日咳毒素处理对促甲状腺激素诱导的碘外流增加或胞质Ca2+水平升高没有影响。我们的数据表明，两种对百日咳毒素敏感的GTP结合蛋白参与了α1肾上腺素能信号转导机制的激活，但不参与促甲状腺激素诱导的FRTL-5细胞中导致碘外流的信号转导机制的激活。
