2003 Fiscal Year Final Research Report Summary
Measurement of mechanical properties of vascular smooth muscle cells as a model of functional materials
| Project/Area Number |
13450040
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Materials/Mechanics of materials
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| Research Institution | Nagoya Institute of Technology (2002-2003)
Tohoku University (2001) |
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Principal Investigator |
MATSUMOTO Takeo Nagoya Institute of Technology, Graduate School of Engineering, Professor, 工学研究科, 教授 (30209639)
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| Co-Investigator(Kenkyū-buntansha) |
NAGAYAMA Kazuki Nagoya Institute of Technology, Graduate School of Engineering, Research Associate, 工学研究科, 助手 (10359763)
OHASHI Toshiro Tohoku University, Graduate School of Engineering, Associate Professor, 大学院・工学研究科, 助教授 (30270812)
SATO Masaaki Tohoku University, Graduate School of Engineering, Professor, 大学院・工学研究科, 教授 (30111371)
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| Project Period (FY) |
2001 – 2003
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| Keywords | Biomechanics / Cellular Mechanics / Cytoskeleton / Organelle / Microscope / Mechanical Adaptation |
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| Research Abstract |
Vascular smooth muscle cells not only change blood vessel diameter through their contraction and relaxation, but also remodel blood vessel wall by producing extracellular matrices such as collagen. Their contractile properties and matrix synthesis change in response to the mechanical stimuli applied to them : For example, their contractile velocity increases with repetitive contraction, and the energy necessary to maintain their isometric contraction decreases when the cells are kept contracted. Thus, the smooth muscle cells have interesting characteristics as a functional material. In this three-year study, we have examined the mechanical properties and the contractile properties of the vascular smooth muscle cells in a single cell level to clarify their relationship with the mechanical stimuli. In the first year, we found that the elastic modulus of the smooth muscle cells isolated from the hypertensive rat thoracic aorta was about one half of that of the normotensive aorta. In the s
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econd year, we found that the elastic modulus of the smooth muscle cells obtained from the rabbit thoracic aorta increased by the factor of 10 when they got contracted. In the last year, we examined the relationship between the tensile properties of the cell and the amount of their intracellular actin filament : We first measured the tensile properties of the smooth muscle cells freshly isolated from the normotensive rat thoracic aortas (FSMCs) and those of the cultured cells of the same origin (Passage 4-9, CSMCs). Then, we stained the cells with rhodamine-phalloidin for actin filaments to know the difference in the actin filament amount between the FSMCs and the CSMCs. The initial elastic modulus of the cells was about 11 kPa (N=8) for FSMCs and about 2.6 kPa (N=10) for CSMCs. The actin filaments in the FSMCs were abundant in the cytosol and it was hard to distinguish each filaments, while in the CSMCs, the filaments were sparsely distributed and stress fibers are clearly distinguishable, indicating that the decrease in the actin filament amount in the CSMCs. Such difference in the actin filament amount may cause the difference in the mechanical properties of the cells. We should analyze quantitatively the relationship between the actin filament amount and the mechanical properties in the next study. Less
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