The effects of the pharyngeal non-noxious mechanical stimulation on the secretion of immunoreactive thyroxin (iT4), immunoreactive calcitonin (iCT), and immunoreactive parathyroid hormone (iPTH) into thyroid venous blood were examined in anesthetized rats. Secretion rates of iT4, iCT, and iPTH were calculated from their concentration in thyroid venous plasma and the plasma flow rate. A mechanical stimulation was delivered to the pharynx by a rubber balloon placed on the tongue that was intermittently pushed into the pharyngeal cavity. Pharyngeal stimulation increased iT4 and iCT secretion, but iPTH secretion was unchanged. The secretion responses were abolished by transecting the superior laryngeal nerves (SLNs) bilaterally. The activities of the thyroid parasympathetic efferent nerves and the afferent nerves in the SLN increased significantly during pharyngeal stimulation. These results indicate that pharyngeal mechanical stimulation promotes thyroxin and calcitonin secretion from the thyroid gland by a reflex increase in SLN parasympathetic efferent activity, triggered by excitation of SLN mechanoreceptive afferents.

中文翻译：

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麻醉大鼠的咽部机械刺激可调节甲状腺静脉血中甲状腺素和降钙素的分泌。

在麻醉的大鼠中检查了咽部非伤害性机械刺激对甲状腺静脉血中分泌免疫反应性甲状腺素（iT4），免疫反应性降钙素（iCT）和免疫反应性甲状旁腺激素（iPTH）的影响。根据iT4，iCT和iPTH在甲状腺静脉血浆中的浓度和血浆流速计算出它们的分泌率。通过放置在舌头上的橡胶气球将机械刺激传递到咽部，该气球被间歇地推入咽腔。咽刺激可增加iT4和iCT分泌，但iPTH分泌未改变。通过双侧横断喉上神经（SLNs）来消除分泌反应。咽刺激过程中，副交感神经中的甲状腺副交感神经和传入神经的活动明显增加。这些结果表明，咽部机械刺激通过SLN机械感受性传入神经的激发而反射性增加SLN副交感神经传出活性，从而促进甲状腺分泌甲状腺素和降钙素。