Thyroid Hormone Controls the Function of Hypothalamic GRF and SRIF Neurons

甲状腺激素控制下丘脑 GRF 和 SRIF 神经元的功能

基本信息

批准号：
01044019
负责人：
SUZUKI Mitsuo
金额：
$ 5.5万
依托单位：
Institute of Endocrinology, Gunma University
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01044019/
关键词：
GRF SRIF The arcuate nucleus Periventricular nucleus Thyroid hormone Growth hormone Fos-like protein Thyroid hormone receptor

项目摘要

1. Neuronal networks of hypothalamic GRF and SRIF neurons in adult male rats and the role of SRIF in relation to growth hormone (GH) secretion.(1) GRF neurons in the arcuate nucleus (Arc) were connected to the vasolateral amygdala (BLA) via the stria terminals, while SRIF neurons in the periventricular nucleus (Pe), have connections to noradrenergic neurons in the brain stem. (2) Pe lesion markedly reduced SRIF content in the median eminence and blunted the sensitivity of pituitary GH cells to GRF stimulation. (3) SRIF pretreatment facilitated 2-fold GH release from the dispersed cells and also the increase in intracellular free Ca^<2+> ions by GRF stimulation.2. Effects of thyroid hormone on fos-like protein, thyroid hormone and SRIF receptors.(1) A number of fos-like immunoreactivity (IR) was examined in adult male rat brains and the IRs were found in the magnocellular and parvocellular regions of the paraventricular nucleus (mPVN & pPVN), anterior hypothalamus, lateral hypothalamus, … More and pyriform cortex. Six days after thyroidectomy (Tx), the number of fos-like IR cells increased 2-fold in PVN. (2) The mRNA of erbA alfa2, one of thyroid hormone recepror family was widely distributed in rat brains, particularly a dense localization was observed in the PVN, hypothalamic ventromedial nucleus, Arc, the hippocampus, medical amygdala, cerebral cortex, and pyriform cortex. After Tx, there was no significant change in the receptor gene expression in these regions, except in PVN, suggesting a negative feedback interrelation between PVN-TRH neural activity and circulating thyroid hormone concentration. (3) Changes in gene expression of GRF by Tx is still under investigation. But recently Downs et al. (1990) reported that Tx or hypophysectomy stimulates GRF gene expression, while thyroid hormone or GH replacement suppresses the increase, proposing that there is a negative feedback mechanism between GH and GRF gene expression. (4) SRIF receptors in rat brains were widely distributed in the regions such as the cerebral cortex, endopyriform nucleus, hippocampus, habenular nucleus and BLA. The number of SRIF receptor in these regions and PVN significantly increased after Pe lesion. However, Tx caused no change in the receptor number except an increase in BLA and thyroxine replacement could not restore the change. Less

1。成年雄性大鼠的下丘脑GRF和SRIF神经元的神经元网络以及SRIF与生长曲（GH）分泌有关的作用。（1）Arcuate Nouus（ARC）在Arcuate Nouus（ARC）中的GRF神经元通过血管外侧杏仁核（BLA）通过STRIA sria Neurons of srif neurons of srif neurons the of pe rifiv与脑干中的甲肾上腺神经元的连接。（2）PE病变显着降低了中位数中的SRIF含量，并蓝垂体GH细胞对GRF刺激的敏感性。（3）SRIF预处理制备了从分散细胞中释放2倍GH，以及通过GRF刺激的细胞内游离Ca^<2+>离子的增加。2。（1）在成年雄性大鼠的大脑中检查了许多FOS样的免疫反应性（IR）对甲状腺样蛋白质，甲状腺唯一和SRIF受体的影响。皮层皮质。甲状腺切除术（TX）六天后，PVN中FOS样细胞的数量增加了2倍。（2）甲状腺同源家族之一Erba Alfa2的mRNA被广泛分布在大鼠大脑中，尤其是在PVN，下丘脑下丘脑腹膜核，ARC，ARC，ARC，Hippocampus，Hippocampus，Hippocampus，Hippocampus，Medical Amygdala，Medical Amygdala，Medical Amygdala，Medical Amygdala，Medical Amygdala，Medical Amygdala，Medical Amygdala，Medical Amygdala，Cerebral Cortex，Cortrail Cortex，Cyrrimers Corrsirors Cortex。 TX之后，除PVN外，在这些区域中，受体基因表达没有显着变化，表明PVN-TRH中性活性与循环甲状腺激素浓度之间存在负反馈相互关系。（3）TX的GRF基因表达的变化仍在研究中。但是最近唐斯等人。（1990年）报道，TX或下生理切除术刺激了GRF基因的表达，而甲状腺雌雄同体或GH替换抑制了增加的增加，这表明GH和GRF基因表达之间存在负反馈机制。（4）大鼠大脑中的SRIF受体被广泛分布在诸如脑皮质，内皮形核，海马，海洋核和BLA等区域。 PE病变后，这些区域中的SRIF受体数量显着增加。但是，TX不会导致接收器数量变化，除了BLA和甲状腺素替代品的增加无法恢复变化。较少的