Leroux P, Tonon M C, Saulot P, Jegou S, Vaudry H
Gen Comp Endocrinol. 1983 Sep;51(3):323-8. doi: 10.1016/0016-6480(83)90046-1.
Thyrotropin-releasing hormone (TRH) stimulates alpha-melanocyte-stimulating hormone (alpha-MSH) secretion in amphibia as well as thyrotropin-stimulating hormone (TSH) and prolactin secretions in mammals. Since thyroid hormones regulate the stimulatory effect of TRH on TSH and prolactin, the possible role of thyroxine (T4) in the control of alpha-MSH secretion in amphibia, has been investigated. Neurointermediate lobes of Rana ridibunda were perifused in amphibian culture medium for 7 hr and the amounts of alpha-MSH released into the effluent perfusate were measured by radioimmunoassay. In vivo treatment with T4 (0.5 mg/kg twice a day for 9 days) did not modify the in vitro response of the neurointermediate lobes to TRH (10(-9) to 10(-7) M). In addition, prolonged infusion of T4 in vitro did not alter spontaneous and TRH-induced alpha-MSH release. In spite of the inhibitory effect of T4 on TRH-induced TSH and prolactin secretions in mammals, the present data show that, in frogs, thyroid hormone does not modulate the stimulation of alpha-MSH secretion induced by TSH.
促甲状腺激素释放激素（TRH）可刺激两栖动物分泌α-黑素细胞刺激素（α-MSH），以及刺激哺乳动物分泌促甲状腺激素（TSH）和催乳素。由于甲状腺激素调节TRH对TSH和催乳素的刺激作用，因此对甲状腺素（T4）在控制两栖动物α-MSH分泌中的可能作用进行了研究。将食用蛙的神经中间叶在两栖动物培养基中灌流7小时，并通过放射免疫测定法测量释放到流出灌流液中的α-MSH量。用T4进行体内治疗（每天两次，每次0.5mg/kg，持续9天）并未改变神经中间叶对TRH（10^-9至10^-7M）的体外反应。此外，在体外长时间输注T4并未改变自发和TRH诱导的α-MSH释放。尽管T4对哺乳动物中TRH诱导的TSH和催乳素分泌具有抑制作用，但目前的数据表明，在青蛙中，甲状腺激素不会调节TSH诱导的α-MSH分泌刺激。
