Localization of thyroid hormone receptor beta2 in the ventral medullary neurons that synthesize thyrotropin-releasing hormone.
Localization of thyroid hormone receptor beta2 in the ventral medullary neurons that synthesize thyrotropin-releasing hormone.
复制标题
甲状腺激素受体β2定位于合成促甲状腺素释放激素的腹侧髓质神经元。
DOI：
10.1016/s0006-8993(00)02251-4
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发表时间：
2000
期刊：
影响因子：
2.9
通讯作者：
Yang,H
中科院分区：
文献类型：
--
作者：
Yuan,PQ;Yang,H
甲状腺状态的改变与自主神经障碍有关。促甲状腺激素释放激素(TRH)在延髓中缝苍白带(RPA)、隐缝中缝(ROB)和丘脑束旁核(PPR)合成，调节迷走神经和交感节前运动神经元。甲状腺功能减退使这些核团TRH基因表达和c-Fos免疫反应(IR)增强。采用免疫组织化学方法和地高辛标记的促促甲状腺激素释放激素原cRNA探针原位杂交技术，检测甲状腺激素受体β2(TRCR2)在RPA、ROB和PPR促促甲状腺激素合成神经元中的表达，探讨其是否为甲状腺激素的直接作用。β-2IR广泛分布于延髓，主要定位于细胞核内。RPA、ROB和PPR神经元均有较强的免疫反应。免疫组织化学结合原位杂交结果显示，延髓腹侧核内TRH原β-2IR阳性神经元也全部呈阳性反应。6-正丙基-2-硫氧尿嘧啶诱发的甲状腺功能正常大鼠和甲状腺功能低下大鼠4周后，β-2免疫反应阳性神经元数目在各核团内基本相同。TRTRH2定位于延髓腹侧核促β合成神经元，为甲状腺激素直接作用于这些神经元调节TRH基因表达提供了解剖学基础，这可能是不同甲状腺状态下自主神经活动改变的原因之一。
Altered thyroid statuses are associated with autonomic disorders. Thyrotropin-releasing hormone (TRH) synthesized in medullary raphe pallidus (Rpa), raphe obscurus (Rob) and the parapyramidal regions (PPR) regulates vagal and sympathetic preganglionic motoneurons. Hypothyroidism increased TRH gene expression and c-Fos immunoreactivity (IR) in these nuclei. Whether these increases represent a direct action of thyroid hormone was studied by detecting the presence of thyroid hormone receptor β2 (TRβ2) in pro-TRH-synthesizing neurons in the Rpa, Rob and the PPR using immunohistochemistry with specific TRβ2 antiserum and in situ hybridization with digoxigenin-labeled pro-TRH cRNA probe. TRβ2 IR was widely distributed throughout the medulla and primarily localized within the cell nuclei. Particularly intense immunostaining was presented in the Rpa, Rob and the PPR neurons. The combination of immunohistochemistry with in situ hybridization revealed that all pro-TRH mRNA-positive neurons in these ventral medullary nuclei were also TRβ2 IR positive. The numbers of TRβ2 IR-positive neurons in each nucleus were identical in both euthyroid rats and hypothyroid rats induced by 6-n-propyl-2-thiouracil in drinking water for 4 weeks. The finding that TRβ2 localized in pro-TRH-synthesizing neurons in the ventral medullary nuclei provides an anatomical substrate for a direct thyroid hormone action on these neurons in the regulation of TRH gene expression, which may contribute to the altered autonomic activity in different thyroid statuses.