Effect of pentoxifylline on adherence of sickle erythrocytes to vascular endothelial cells

Abstract

The effect of pentoxifylline (PTX) on red blood cell-endothelial cell adherence was studied for sickle and normal red blood cells (RBC). Human umbilical vein endothelial cells grown to confluence on glass slides formed the base of a parallel plate flow chamber into which RBC suspensions were perfused at a constant flow rate, producing a wall shear stress of 1 dyne/cm². RBC were incubated with PTX at 37°C for one hour at concentrations ranging from 0.1 to 10.0 mmol/L. Adhesion was monitored using video microscopy. The number of adherent RBC was determined at 10-minute intervals during a wash-out period which followed a 10-minute perfusion of red cells. When compared with unincubated control RBC, the adherence of sickle RBC incubated with 0.1, 1.0 and 10.0 mmol/L of pentoxifylline was reduced to 65%, 53% and 39% of control values, respectively. There was no significant difference between the adherence of drug incubated and untreated normal RBC. These results indicate that pentoxifylline significantly affects the adhesion of sickle RBC to cultured human endothelial cells, but has no effect on the adherence of normal RBC.