Cellular organization and neuronal inducer (inhibitor) in Xenopus adenohypothesis.

非洲爪蟾腺假说中的细胞组织和神经元诱导剂（抑制剂）。

基本信息

批准号：
08640841
负责人：
TANAKA Shigeyasu
金额：
$ 1.6万
依托单位：
Shizuoka Universty (1997)Gunma University (1996)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08640841/
关键词：
Pituitary gland Pars intermedia Hypothalum Xenopus laevis Neuronal inducer Bioassay Proopiomelanocortin alpha-MSH 視床下部神経

项目摘要

The adenohypophysis consists of two distinct parts, the pars distalis and the pars intermedia, both derived from a common embryonic rudiment called Rathke's pouch and regulated by the hypothalamus. However, the control mechanisms of the pars distalis and the pars intermedia are different from each other. Hormone-producing cells in the pars distalis are controlled by hypothalamic hormones produced by hypothalamic neurons carried via hypothalamo-hypophysial blood vessels, whereas the melanotrope cells in the pars intermedia are controlled directly by the hypothalamic neurons. Evidence of these mechanisms is the great number of blood vessels located in the pars distalis, whereas in the pars intermedia, the blood vessels are not nearly so well developed, and also by the many axons penetrating the pars intermediate. Such histological observations create a working hypothesis that the pars intermedia produces some factors that induce neurons, whereas the pars distalis secretes some factors in … More ducing morphogenesis of blood vessels. To identify these factors, I have tried to establish an in vitro bioassay system for quantitating the presence and length of the axons projecting from hypothalamic neurons into the pars intermedia. I co-cultured suprachiasmatic nuclei from hypothalamus of Xenopus tadpoles in collagen-matrix with pars intermedia from identical stages of development or from the adult toad, and counted the number of axons growing from the superchiamatic nuclei a fixed period of incubation. I observed a slight difference in the outgrowth of the axons when the suprachiasmatic nuclei were co-cultured with either the pars distalis or the pars intermedia, but the quantity and reproducibility of the observation were low. In the course of studies on the characterization of melanotrope cells in the Xenopus pars intermedia, I have found that the prohormone convertases PC1 and PC2 are involved in the proteolytic processing of proopiomelanocortin into alpha-MSH by using specific antibodies against the mammalian enzymes. Less

腺垂体由两个不同的部分组成，即远端部和中间部，两者均源自称为拉特克囊的常见胚胎雏形并受下丘脑调节，但是远端部和中间部的控制机制彼此不同。远端部的激素产生细胞由下丘脑神经元产生的下丘脑激素控制，这些激素通过这些机制的证据是位于远端的大量血管，而中间部的血管则不受下丘脑-垂体血管的控制。几乎如此发达，而且通过许多轴突穿透中间部，这种组织学观察产生了一个工作假设，即中间部产生一些诱导神经元的因子，而中间部产生一些诱导神经元的因子。为了识别这些因素，我试图建立一个体外生物测定系统，用于定量从下丘脑神经元投射到我共培养的中间部的轴突的存在和长度。来自爪蟾蝌蚪下丘脑的视交叉上核，在胶原基质中，具有来自相同发育阶段或来自成年蟾蜍的中间部，并计数当视交叉上核与远侧部或中间部共培养时，我观察到从视交叉上核生长出的轴突在固定的孵化期中存在轻微差异，但观察的数量和再现性是不同的。在对非洲爪蟾中间部黑素细胞特性的研究过程中，我发现激素原转化酶 PC1 和 PC2。通过使用针对哺乳动物酶的特异性抗体，参与将阿黑皮质素原蛋白水解为 α-MSH。