Affiliations: [a] Kansai University, Suita, Japan
| [b] Osaka University, Toyonaka, Japan
Correspondence:
[*]
Address for correspondence: Masako Sugihara-Seki, Department of Pure and Applied Physics, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan. Fax: +81-6-6368-0866; E-mail: sekim@kansai-u.ac.jp.
Abstract: Background:In the microcirculation, red blood cells (RBCs) were observed to be confined to an axial stream surrounded by a marginal RBC depleted layer. This axial accumulation of RBCs is considered to arise from the RBC deformability. Objective:To quantitatively evaluate the effect of RBC deformability on their axial accumulation at a flow condition comparable to that in arterioles by developing a new observation system for accurate measurements of radial RBC positions in the cross section of capillary tubes. Methods:The cross-sectional distributions of normal and hardened RBCs as well as softened RBCs suspended in capillary tube flows were measured with high spatial resolution. A new observation system was developed in which enface views of the cross-section of the tube were obtained at small distances upstream of the outlet at various longitudinal positions in the tube. Results:
The radial positions of individual RBCs were detected within 1 μm accuracy. It was found that normal and softened RBCs rapidly migrated away from the wall towards the tube axis, whereas glutaraldehyde-hardened RBCs were dispersed widely over the tube cross-section, depending on the concentration of glutaraldehyde solution.
Conclusions:The newly devised observation system revealed quantitatively the essential role of RBC deformability in their axial accumulation.
