1990 Fiscal Year Final Research Report Summary
Characterization of Muscarinic Receptors in Singl Smooth Muscle Cells
| Project/Area Number |
01571224
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Biological pharmacy
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| Research Institution | Department of Pharmacology, School of Pharmaceutical Sciences, Showa University |
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Principal Investigator |
MOMOSE Kazutaka Department of Pharmacology, School of Pharmaceutical Sciences Showa University Professor, 薬学部・薬理学教室, 教授 (80004597)
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| Co-Investigator(Kenkyū-buntansha) |
FAN Yan-Il Department of Pharmacology, School of Pharmaceutical Sciences Showa University R, 薬学部・薬理学教室, 助手 (50228855)
OHATA Hisayuki Department of Pharmacology, School of Pharmaceutical Sciences Showa University R, 薬学部・薬理学教室, 助手 (00119166)
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| Project Period (FY) |
1989 – 1990
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| Keywords | 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 in contraction of smooth / movement of intracellular calcium in smooth muscle / 03determination of contractile responses of single muscle cells / 05mode of contractile responses of visceral smooth muscle / 07role of phosphatidic acid in contraction of smooth muscle / 08movement of intracellular calcium in smooth muscle cells |
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| Research Abstract |
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.
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