Blood Vessel Depredation by Wall Shear Stress.

Development of Evaluation System of Blood Vessel Depredation and Experimental Investigation by Blood Flow Induced Mechanical Stresses

In this research, aimed at studying mechanism of blood vessel depredation by blood flow induced mechanical stresses, we develop the evaluation system of blood vessel depredation (Fig.1) that makes mechanical stresses (Fig.2) to act on internal wall of the blood vessel removed from an animal on environment in culture. And we experimentally investigate blood vessel depredation by blood flow induced wall shear stress.

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Fig. 1 Evaluation System of Blood Vessel Depredation

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Fig. 2 Blood Flow Induced Mechanical Stresses

For quantitative evaluation of blood vessel depredation, we focus attention on the density of endothelial cells that cover the inner face of blood vessel. Fig.3 shows that the changes in endothelial cell density (ECD) with wall shear stress (WSS) escalated by flow rate control. When WSS surpasses a threshold level, which varies in each samples, ECD decrease dominantly. Additionally internal face picture shows that endothelial cells are unstuck locally then (Fig.4).

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Fig. 3 ECD changes with WSS escalate

Thus, by quantitative investigation of the vessel tissue removed from an animal, we try clarifying pathogenic mechanism of blood vessel diseases such as aneurysm and studying the relation with blood flow induced mechanical stresses.

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Fig. 4 Endothelial Cells are Unstuck Locally (sample3, WSS: 173dyn/cm2)

References
R. Iida, S. Yamamoto, N. Kojima, T. Yamamoto, Y. Sakai, M. Oshima, Quantitative Investigation of Depredation
by Blood Flow Induced Mechanical Stresses ~Development of in vitro Evaluation System of Blood Vessel
Depredation, The Japan society of Mechanical Engineering No.06-46, Proceedings of the 17th JSME Conference of
Frontiers in Bioengineering (Ueda-shi 2006), pp.53-54.
R. Iida, S. Yamamoto, N. Kojima, T. Yamamoto, Y. Sakai, M. Oshima, Experimental Investigation of Depredation
by Blood Flow Induced Mechanical Stresses, The Japan society of Mechanical Engineering No.06-65, Proceedings of the 19th Bioengineering Conference (Sendai-shi 2007), pp.300-301.