Rheological blood properties under conditions of mechanical stress

A. Oslyakova, I. Tikhomirova, E. Petrochenko

Abstract: The efficacy of delivery of blood oxygen to tissues at the level of the microcirculation is greatly determined by the rheological properties of blood, in particular, erythrocyte aggregability and their ability to deform when passing through the capillaries. In circulation erythrocytes are constantly exposed to external various physical influences, one of which is mechanical stress. The aim of study was to evaluate the influence of mechanical stress on rheological blood properties.
The influence of mechanical stress was estimated by the method of T. Oonishi et al. (1997). We measured the viscosity of a suspension of erythrocytes in plasma with a fixed Hct 40, the extent of erythrocytes aggregation (by means of optical microscopy of diluted blood following by subsequent computer image analyzing) and erythrocyte deformability (by indices of elongation in flow microchamber at a fixed shear stress).
The decreased viscosity of erythrocyte suspensions in plasma at high as well as at low shear stress under mechanical stress applying is demonstrated (by 9% and by 8% (p<0.05), respectively). It was determined by decrease of erythrocyte aggregability: the extent of erythrocytes aggregation decreased by 23% (p<0.05), the number of cells in the erythrocyte aggregates reduced by 12% (p<0.05). The deformability of erythrocytes under the action of mechanical stress increased by 9% (p<0.01) compared to the control.
The positive changes of rheological blood properties under conditions of mechanical stress were revealed that might be considered as an adaptive response of cells aimed to maintain the oxygen-carrying function of blood at an optimal level.

Keywords: aggregation; Blood rheology; deformability; erythrocytes; mechanical stress

Date published: 2015-12-10