FLUID SHEAR-INDUCED ENDOTHELIAL-CELL DETACHMENT FROM GLASS - INFLUENCE OF ADHESION TIME AND SHEAR-STRESS

In this study, human umbilical vein and human saphenous vein endotheli al cells ware seeded on glass and exposed to fluid shear in a parallel -plate flow chamber. cell retention, morphology and migration were stu died as a function of shear stress and of adhesion time prior to expos ure to shear. Three-hour and 24-h adhesion limes gave rise to comparab le cell retention values after 2 h of flow for both cell types. Cell r etention decreased from 85 to 20% as shear stress increased from 88 to 264 dynes cm(-2) (8.8 to 26 Pa). Mean spreading areas decreased after the onset of flow, but subsequently stabilized to plateau values, whi ch mere smaller at higher shear stresses. Shape factors increased fast er to higher values as cells were exposed to higher shear stresses, wi thout any obvious preference in orientation of the cells with respect to the direction of flow. Migration was unidirectional with flow and l inear with time. Migration was faster for cells which had adhered for 24 h than for cells which had adhered for 3 h and was accompanied by t he presence of fibrillar structures left behind on the surface upstrea m of migrating cells. It is concluded that after 3 h adhesion to glass , cells have adhered with an adhesion strength that does not substanti ally increase during tire next 21 h. However, during this time changes in cell-substratum interactions seem to occur judging by the differen ces in, e.g., migration rates.