Aspirin analogues and flow of erythrocytes through narrow capillaries

Abstract

We demonstrate that in vitro incubation of erythrocytes from normal human adults in a series of aspirin analogues of increasing lipophilicity leads to a correspondingly decreased resistance (apparent viscosity) to their flow in narrow capillaries. No particular trend was observed in mean cell volume and morphologic characteristics of the cells. These observations demonstrate that erythrocyte flow characteristics are affected even before any observable changes occur in morphologic and geometric characteristics. We suggest that other changes occur in the membrane constitution which lead to a decreased membrane elastic stiffness and shear viscosity. These changes are greater with more lipophilic salicylates, perhaps, because they are adsorbed to a greater degree in the lipid bilayer and they disrupt the constitution of the membrane to a greater extent.