Abstract
Erythrocyte flow behavior in microvessels affects not only flow resistance, but also oxygen transfer to peripheral tissues. Erythrocytes flowing through a microvessel tend to accumulate in the central flow axis, and thus cell-free layer appears along inner wall of the vessel. The oxygen release from flowing erythrocytes was examined using an oxygen-permeable fluorinated ethylenepropylene copolymer tube (inner diameter, 0.027 mm). After exposing the narrow tube to deoxygenated environment, the oxygen saturation was measured with a spectrophotometer under a microscope. We modified the flow behavior of erythrocytes by applying accelerational force perpendicularly to the flow direction using a centrifuge or by perfusing erythrocytes reduced in sialic acid content of the membrane proteins with neuraminidase to decrease electrostatic interaction among erythrocytes.(1) With increasing the centifugal force, the oxygen release from flowing cells was suppressed accompanying the shift of the cell flow column to centrifugal side and the compression of the flow column.(2) With decreasing sialic acids of erythrocytes, oxygen release from cells was decreased, especially at low pH condition (pH=6.5). In conclusion, this research suggests that accumulation of flowing erythrocytes affects the oxygen diffusion from erythrocytes to tissue in microcirculation. [Jpn J Physiol 55 Suppl:S90 (2005)]
