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Characterization of Muscarinic Receptors in Singl Smooth Muscle Cells

单个平滑肌细胞中毒蕈碱受体的表征

基本信息

批准号：
01571224
负责人：
MOMOSE Kazutaka
金额：
$ 0.7万
依托单位：
Department of Pharmacology, School of Pharmaceutical Sciences, Showa 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：
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-01571224/
关键词：
Smooth Muscle Muscarinic Receptor determination of contractile responses of single m preparation of single muscle cells mode of contractile responses of visceral smooth m affinity of muscarinic receptors to agonists role of phosphatidic acid i

项目摘要

Characteristics of muscarinic receptors in guinea pig visceral muscles and the single cells prepared by enzymatic digestion were investigated.Preparation of single smooth muscle cells : Enzymatic digestion of smooth muscle, with combination of highly purified collagenase and papain, yielded single cells which were responsive to various agonists.Determination of contractile responses of single muscle cells : A procedure for determination of contractile responses of single muscle cells was developed with use of a phase contrast microscope and a microcomputer.Mode of contractile response of single smooth muscle cells : The dispersed cells were contracted by carbachol dose-dependently, indicating that the mode of contraction was graded type. Each cell, however, had different sensitivity to agonists and the dose-response curves were different in each cell. Superimpose of those curves became resembled to that obtained with the intact tissue suggesting that force development of each cell in the tissue evoked contraction of the tissue. Characteristics of the muscarinic receptors in the single cells : Affinity to agonists in the isolated single cells were not altered during preparation of the cells by enzymatic digestions. With use of the single cells, it was revealed that the muscarinic receptors in the visceral muscle were consisted of three subtypes and each pKi was 7.1, 5.8 and 4.0.Role of phosphatidic acids in contraction of smooth muscle : Stimulating the muscarinic receptors, phospholipase C and diacylglycerol Kinase were activated, and content of intracellular phosphatidic acid was increased. The acid stimulated release of intracellular free calcium which induced muscle contraction.

研究了豚鼠内脏肌中毒蕈碱受体的特性和酶消化法制备的单个细胞。单个平滑肌细胞的制备：用高度纯化的胶原酶和木瓜蛋白酶组合酶消化平滑肌，产生对各种激动剂有反应的单个细胞。单个肌细胞收缩反应的测定：用相差显微镜和微型计算机建立了测定单个平滑肌细胞收缩反应的方法。单个平滑肌细胞收缩反应的模式：卡巴胆碱剂量依赖性地使分散的细胞收缩，表明收缩方式为分级型。然而，每个细胞对激动剂的敏感性不同，并且每个细胞的剂量-反应曲线也不同。这些曲线的叠加变得类似于用完整组织获得的曲线，表明组织中每个细胞的力发展引起组织的收缩。单细胞中毒蕈碱受体的特征：在通过酶消化制备细胞的过程中，分离的单细胞中对激动剂的亲和力没有改变。结果表明，内脏肌中的M受体可分为三种亚型，其pKi分别为7.1、5.8和4.0。磷脂酸在平滑肌收缩中的作用：M受体可激活磷脂酶C和甘油二酯激酶，使细胞内磷脂酸含量增加。酸刺激细胞内游离钙的释放，引起肌肉收缩。