| Project/Area Number |
14550142
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Fluid engineering
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
TADA Shigeru Tokyo Institute of Technology, Mechanical Engineering, Assistant Professor, 大学院・理工学研究科, 助手 (70251650)
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| Co-Investigator(Kenkyū-buntansha) |
TARBELL John, M. City College of New York/CUNY, Biomedical Engineering, Professor
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2003: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2002: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Smooth muscle cells / Wall shear stress / Calcium signal transduction / mass transport / Low density lipo protein / ATP / フォトンカウンティング法 |
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| Research Abstract |
Vascular smooth muscle cells (VSMCs) embedded in an arterial medium are normally shielded from the direct shear stress of flowing blood and are exposed to direct blood flow after vascular injury. Because of the importance of intracellular Ca^<2+> concentration ([Ca^<2+>]i) in regulating vascular tone and functions, we investigated the effect of fluid flow shear stress on [Ca^<2+>]i in human aortic smooth muscle cells (HASMCs) in terms of a newly developed single-photon counting technique. In the presence of 2.0mM extracellular Ca^<2+>, a shear stress of [16 dynes/cm^2] applied for 60 s to the top surface of the HASMC monolayer elicited a sharp increase in [Ca^<2+>]i followed by multiple elevation of lesser magnitude. Results suggest that the influx of extracellular Ca^<2+> contributes to the increase in the cytosolic Ca^<2+> concentration of VSMCs in response to fluid flow shear stress.
On the other hand, we have developed a two-dimensional numerical simulation model to resolve the influence of the IEL on convective-diffusive transport of macromolecules in the media. The model considers interstitial flow in the medial layer that has a complex entrance condition due to the presence of leaky fenestral pores in the IEL. Results for ATP and LDL demonstrate a range of interesting features of molecular transport and uptake in the media that are determined by considering the balance among convection, diffusion and SMC surface reaction. In addition we observe that transport of LDL to SMC surfaces is likely to be limited by the fluid phase (surface concentration less than bulk concentration), whereas ATP transport is limited by reaction on the SMC surface (surface concentration equals bulk concentration).
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