Mechanism of Action of Various Psychotropic Agents on Monoaminergic Receptors and Transmembrane signal Control.

各种精神药物对单胺能受体的作用机制和跨膜信号控制。

基本信息

批准号：
60570490
负责人：
MIKUNI Masahiko
金额：
$ 1.34万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1985
资助国家：
日本
起止时间：
1985 至 1986
项目状态：
已结题

项目摘要

The metabolism of inositol phospholipids in response to 5HT was investigated in human platelets using the sensitive radioisotopicmethod of Berridge (1983), since it is well-known that ketanserin antagonizes 5HT-induced shape change and rise of intracellular free Ca ion. In platelets prelabeled with <^3H> -myo inositol, in Ca ion free HEPES buffer containing 10mM Licl and l <micro> M fluoxetine, 5HT caused a dose-dependent accumulation of inositol-l-phosphate(IP-l) during 15 min incubation. A maximal increase in IP-l formation was observed at 30 <micro> M of 5HT and its <EC_(50)> value was 4 <micro> M. Ketanserin, a selective 5HT-2 antagonist, was a potent inhibitor of 5HT-stimulated IP-l accumulation with a Ki value of 12nM, but a selective 5HT-l antagonist, (-)-propranolol(l <micro> M), failed to block the 5HT response. Metergoline, a mixed 5HT-l and 5HT-2 antagonist, caused almost the same reduction in 5HT-stimulated IP-l formation, with a Ki value of 5nM, as ketanserin. These results indicate that 5HT is activating 5HT-2,but not 5HT-l receptors in human platelets. Moreover, chlorpromazine and imipramine inhibited 5HT-stimulated IP-l accumulation, with Ki values of 124nM and 2560nM, respectively. Spiperone(l <micro> M) inhibitedcompletely, and clozapine(l <micro> M) and amitriptyline(l <micro> M) reduced partially(80-50%), 5HT-induced IP-l accumulation; sulpiride(l <micro> M) failed to block the 5HT response. The potencies of these compounds to inhibit 5HT-stimulated IP-l accumulation in human platelets correlates positively with the affinities to 5HT-2 receptors as defined by radioligand binding in rat cerebral cortical membranes. This extends the usefulness of the platelets as a model for 5HT-2 receptors since ligand binding studies can be complemented by measurements of a defined biochemical response.

使用Berridge（1983）的敏感的放射性分析方法在人血小板中研究了肌醇磷脂的代谢，因为众所周知，酮酸盐会拮抗5HT诱导的形状变化和细胞内无基离子的上升。在带有<^3H> -Myo肌醇预先标签的血小板中，在含有10mm LICL和L <micro> M氟西汀的CA离子HEPES缓冲液中，5HT在15 min孵化过程中导致肌醇-l-磷酸（IP）的剂量依赖性依赖性剂量依赖性。在30 <micro> m的5HT时观察到IP-L形成的最大增加，其<ec_（50）>值为4 <micro> M.酮类素，一种选择性的5HT-2拮抗剂，是5HT刺激的IP-L积累的有效抑制剂，具有12nm的Ki值，但是12NM，但选择性5HT-LHT-L抗抗元素（l MICROAL）（l MICROR）（l），<<<<<） - <<<<<） - <<<<<<） - <<<<）阻止5HT响应。元素元（一种混合的5HT-L和5HT-2拮抗剂）与酮蛋白的Ki值为5nm，在5HT刺激的IP-L形成中几乎相同的降低。这些结果表明5HT激活了5HT-2，但在人血小板中没有激活5HT-L受体。此外，氯丙嗪和咪吡金抑制了5HT刺激的IP-L积累，Ki值分别为124nm和2560nm。尖型（L micro> m）抑制了抑制，氯氮平（L micro> m）和阿米替林（L micro> m）部分减少（80-50％），5HT诱导的IP-L积累； Sulpiride（L <micro> m）未能阻止5HT响应。这些化合物抑制人血小板中5HT刺激的IP-L积累的功能与大鼠脑皮质膜中的放射性结合所定义的5HT-2受体的亲和力正相关。这扩展了血小板作为5HT-2受体模型的有用性，因为配体结合研究可以通过定义的生化反应的测量来补充。