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A Enzyme Cytochemical Study of Intra-Cellular Singnaling System of Anterior Pituitary Hormone Producing Cells.

垂体前叶激素产生细胞细胞内信号系统的酶细胞化学研究。

基本信息

批准号：
09670024
负责人：
YASHIRO Takashi
金额：
$ 1.54万
依托单位：
JICHI MEDICAL SCHOOL
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09670024/
关键词：
pituitary cAMP adenylate cyclase enzyme cytochemistry guanylate cyclase phosphodiesterase 5'-nucleotidase marginal cell layer 下垂体前葉酵素組織細胞化学 GH-RH PACAP CRH

项目摘要

It is well understood that extracellular stimuli produce specific responses in the cells by changing the intracellular concentrations of cyclic-AMP and that adenylate cyclase is the enzyme which gives rise to it. Cyclic-AMP in the cell is degraded by cyclic 3',5'-nucleotide phosphodiesterase into adenosine monophosphate, then adenosine monophosphate receives a break-down by 5'-nucleotidase into adenosine and orthophosphate, and terminally results in a cAMP metabolic cascade. Although the cytochemical localization of these enzymes have been studied in many organs, almost no report has appeared on the pituitary gland. The present study aimed at knowing localization of these enzymes in the rat anterior pituitary gland by means of electron microscopic enzyme histochemistry, introducing the following media of Saito and Keino (1975) for adenylate cyclase, Takizawa and Saito (1992) for phosphodiesterase, and Wachstein and Meisel (1975) for 5'-nucleotidase.The reaction product for adenylate cy … More clase activity was observed on the plasma membrane of GH cells. Strongly positive reaction product was observed on the microvilli of some folliculo-stellate cells (F-S cells). The phosphodiesterase activity was demonstrated as positive in the cytoplasm of the PRL cells. In some GH cells, reaction product was weakly observed in the cytoplasm. The reaction products for 5'-nucleotidase were observed positive on the plasma membrane of some of the LH/FSH cells in addition to the GH cells. The above results interestingly suggest that the anterior pituitary cells present specific differences in the cyclic nucleotide metabolizing enzymes in constituent cells. In addition to the anterior pituitary hormone producing cells, ultracytochemical localization of adenylate cyclase and guanylate cyclase was studied in the marginal cell layer surfacing the pituitary cavity. The cells in the marginal cell layer showed strong activity of adenylate cyclase and guanylate cyclase on the plasm membrane facing to the cavity, including micrivilli and cilia. Similar localization of guanylate cyclase activity was observed. The results suggest that the constituent cells of the marginal cell layer may have some regulatory function on the pituitary gland. Less

众所周知，细胞外刺激通过改变细胞内环磷酸腺苷的浓度而在细胞内产生特异性反应，而腺苷酸环化酶是产生这种反应的酶。细胞内的环amp被环3′，5′-核苷酸磷酸二酯酶降解为单磷酸腺苷，然后单磷酸腺苷被5′-核苷酸酶分解为腺苷和正磷酸，最终导致cAMP代谢级联反应。虽然这些酶的细胞化学定位已经在许多器官中进行了研究，但几乎没有关于脑垂体的报道。本研究旨在通过电镜酶组织化学方法了解这些酶在大鼠垂体前叶中的定位，采用以下培养基：腺苷酸环化酶的培养基为Saito和Keino(1975)，磷酸二酯酶的培养基为Takizawa和Saito(1992), 5'-核苷酸酶的培养基为Wachstein和Meisel（1975）。在生长激素细胞的质膜上观察到更多的酶活性。在部分卵泡星状细胞（F-S细胞）微绒毛上观察到强烈阳性反应产物。磷酸二酯酶活性在PRL细胞的细胞质中呈阳性。在一些GH细胞中，细胞质中观察到较弱的反应产物。除GH细胞外，部分LH/FSH细胞的质膜上也可见5′-核苷酸酶阳性反应产物。有趣的是，上述结果表明垂体前叶细胞在组成细胞中存在环核苷酸代谢酶的特异性差异。除了垂体前叶分泌激素的细胞外，我们还研究了垂体腔表面边缘细胞层中腺苷酸环化酶和鸟苷酸环化酶的超细胞化学定位。边缘细胞层细胞在面向空腔的质膜（包括微绒毛和纤毛）上表现出较强的腺苷酸环化酶和鸟苷酸环化酶活性。观察到类似的鸟苷酸环化酶活性定位。提示边缘细胞层的组成细胞可能对垂体有一定的调节作用。少