| Project/Area Number |
02671065
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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 |
Laboratory medicine
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| Research Institution | Hokkaido University |
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Principal Investigator |
MATSUNO Kazuhiko Hokkaido University School of Medicine Associate Professor, 医学部, 助教授 (70102332)
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| Co-Investigator(Kenkyū-buntansha) |
SAKURADA Keisuke Hokkaido University School of Medicine Lecturer, 医学部, 講師 (80002161)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1991: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1990: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | Platelets / Fibrinogen / Calcium / Thrombin / GMP-140 |
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| Research Abstract |
We investigated fibrinogen binding to platelets using flow cytonietry with fluorescence-labelled fibrinogen. Flow cytonietric analysis, of fibrinogen' binding was simple and superior to radioisotope-labeled fibrinogen binding assay in serial measurement of fibrinogen binding. Fibrinogen binding to platelets was observed in response to thrombin stimulation in a dose-dependent manner, and paralleled to the increase in cytosofic free calcium concentration. Thrombin-induced fibdmgen binding was inhibited by a removal of extracellular Ca^<2+> and by an addition of monoclonal antibody to platelet GP IIb/Illa. Chelating of intracellular Ca^<2+> by an introduction of BAPTA into platelets suppressed fibrinogen binding in a dose-dependent manner. Forskolin also inhibited dirombin-induced fibrinogen binding through the increase in cyclic AMP in platelets.
We studied the surface expression of GMP-140 using flow cytometry. Mr expression of OMP- 140 was increased in response to dirombin stimulation. Thrombin-induced the expression of GMP- 140 was not inhibited by a removal of extracellular Ca^<2+>, but inhibited by an introduction of BAPTA and an addition of forskolin.
We measured the binding of fibrinogen and the expression of OMP-140 in thrombin-activated platelets using flow cytometry simultaneously. Thrombin-induced expression of GMP-140 followed fibrinogen binding to platelets stimulated with dirombin. The introduction of BAPTA into platelets and the addition of forskolin to platelet suspension inhibited dirombin-induced expression of GMP- 140, as well as the binding of fibrinogen.
For reasons mentioned above, we considered that thrombin-induced fibrinogen binding to platelets was closely related to the increase in intracellular Ca^<2+>.
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