| Project/Area Number |
04454132
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
General physiology
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| Research Institution | Juntendo University School of Medicine |
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Principal Investigator |
OCHI Rikuo Juntendo University School of Medicine, Department of Physiology, Professor, 医学部, 教授 (10049025)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥6,400,000 (Direct Cost: ¥6,400,000)
Fiscal Year 1993: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1992: ¥4,500,000 (Direct Cost: ¥4,500,000)
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| Keywords | Endothelial cells / Chloride current / ATP / Calcium ion / Patch clamp / Fura-2 / カルシウム |
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| Research Abstract |
The present study has disclosed the existence of C1- channels in cultured endothelial cells (ETC) from human aorta, human umbilical vein as well as bovine pulmonary artery. The generation of C1- current can be regarded as a common property of the endothelial cells. We used mainly cultured human aortic ETC and measured membrane currents by patch clamp technique and intracellular Ca concentration [Ca]i by fura-2 fluorometry. Major results were : 1) External application of 1-10 uM ATP induced outward-rectifying Cl- currents succeeding to Ca-activated K+ current, 2) With pipette solution of pCa 6 and pCa 5, C1 currents developed with a delay of a few minuts after breaking the patch membrane, 3) The Ca-activated C1- currents were blocked by trifluoperazine and W7, calmodulin antagonists, 4) [Ca]i increased in a bipasic manner by external application of 10 uM ATP, 5) The tonic phase of the ATP- induced [Ca]i increase was suppressed by decreasing [Cl]o from 146 to 20 mM.6) From the change of the leakage current and single channel currents recorded by cell-attached patch clamp technique produced by the change in [K]o, [C1]o and an application of ATP, the resting potential of ETC is at 20-40 mV more depolarized potentials from the reversal potential of K+ ions. It suggests that the functional role of the C1- currents is the stabilization of the resting membrane potential to the depolarized range
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