甲状腺激素对新生期大鼠下丘脑Go蛋白α亚单位的影响

Effect of thyroid hormone on Go protein α subunit in hypothalamus of neonatal rat expression

目的 研究新生期Ｗｉｓｔａｒ 大鼠下丘脑Ｇｏ 蛋白α亚单位（Ｇｏα） 的分布及甲状腺激素对其表达的影响。方法 采用地高辛标记寡核苷酸探针原位杂交技术，对新生期正常及甲减Ｗｉｓｔａｒ 大鼠下丘脑ＧｏαｍＲＮＡ 的表达状况进行研究。结果 （１）ＧｏαｍＲＮＡ 主要分布于新生期Ｗｉｓｔａｒ 大鼠下丘脑的弓状核（ＡＲ）、腹内侧核（ＶＭＨ）等部位；（２）２１ 日龄组大鼠下丘脑诸核团ＧｏαｍＲＮＡ 的转录水平明显低于１４ 日龄组；（３） 甲状腺功能低下可引起１４ 日及２１ 日龄大鼠下丘脑ＡＲ、ＶＭＨ 核团ＧｏαｍＲＮＡ水平显著升高。结论 在大鼠下丘脑的发育过程中，信号蛋白Ｇｏα基因呈现特征性分布及表达，甲状腺激素对该基因具有转录下调作用。

Objective To study the distribution of Go protein α subunit (Goα) mRNA in hypothalamus of neonatal rat and the effect of thyroid hormone on its expression. Methods Non radioactive in situ hybridization technique was used to observe Goα mRNA distribution in the hypothalamic nuclei of 14 and 21 day Wistar rats, both normal and affected by thyroid hormone deficiency. Results (1) Goα mRNA was mainly located in arcuate nucleus (AR) and ventromedial hypothalamic nucleus (VMH) of 14 or 21 day rats; (2) The expression of Goα mRNA in the hypothalamic nuclei of 21 day rat was significantly weaker than that of 14 day rat; (3) Perinatal hypothyroidism could significantly increase Goα mRNA levels in AR and VMH of 14 and 21 day rats. Conclusion Goα mRNA is characteristically distributed and expressed in AR and VMH of neonatal rat, and the transcription of Goα gene in these nuclei can be down regulated by thyroid hormone during development of rat brain.