Surface Charge of Endothelial Cells Estimated from Electrophoretic Mobility

Abstract

The surface charge density of endothelial cells was estimated from cell electrophoresis. Cultured endothelial cells from the bovine pulmonary artery were suspended in saline and placed in the lumen of a glass capillary. A voltage was applied across the capillary ends and the velocity imparted to the cells was measured with a microscope. Erythrocyte mobility was also measured. The mobility in (µm/s)/(V/cm) was 0.74 ± 0.08 for endothelial cells and 1.03 ± 0.15 for erythrocytes. Charge density in esulcm² was calculated as 2.62 × 10⁴ and 0.91 × 10⁴ for endothelial and red cells, respectively. Removal of sialic acid did not affect the mobility of endothelial cells, but it reduced that of red cells to near zero. Endothelial cell mobility decreased either with ionic strength or calcium concentration. Our results strongly suggest that the surface charge of endothelial cells is dependent on sulfated glycosaminoglycans

Key Words:

• Cell surface charge
• endothelial cell surface
• cell electrophoresis
• cell mobility