SHEAR-STRESS INDUCES CHANGES IN THE MORPHOLOGY AND CYTOSKELETON ORGANIZATION OF ARTERIAL ENDOTHELIAL-CELLS

Objectives: The aim of this study was to determine the charges in the morphology and cytoskeleton organisation of endothelial cells (EC) det ermined by exposure to a laminar flow. Cultured EC were exposed to a w all shear stress of 6 dyne/cm(2) for 24 hours. Chief outcome measures: The morphology of EC was analysed by light and scanning electron micr oscopy. The organisation of the cytoskeleton was determined by double fluorescence labeling with antibody anti-vementin, anti-vinculin, anti -tubulin, and with rhodamine-labeled phalloidin. Results: EC exposed t o laminar flow become round-shaped with decreased areas of adhesion to the substrate. There was a clear reorganisation of the cytoskeleton a fter exposure to shear stress; the distribution of actin changed from a stress fibre pattern to a more diffuse membrane associated distribut ion. These changes in shape and cytoskeleton organisation were reversi ble after a 48-hour resting period. Conclusions: EC respond to laminar flow in a predictable manner and these findings may be correlated to the functional changes of EC observed after exposure to shear stress.