CATECHOLAMINES DECREASE LYMPHOCYTE ADHESION TO CYTOKINE-ACTIVATED ENDOTHELIAL-CELLS

Numerous studies have shown that catecholamines can modulate lymphocyt e migration. This effect may be mediated in part by modulation of lymp hocyte-endothelial cell interactions, which is dependent on adhesion m olecules expressed on both of these cells. Our results show that catec holamines decreased T-cell binding to IL-1 activated endothelial cells in vitro. The decrease in adhesion was not mediated by a change in ad hesion molecule expression as LFA-1 and VLA-4 expression on T-cells an d ICAM-1 and VCAM-1 expression on endothelial cells were not changed b y catecholamine stimulation. T-cells flatten and enlarge the area of s urface contact as they adhere to endothelial cells. Image analysis of the number of T-cells bound and the amount of cell spreading over seve ral time points suggests that catecholamines alter the kinetics of T-c ell-endothelial cell adhesion. These results support the hypothesis th at catecholamines can alter lymphocyte-endothelial interactions in viv o, which in turn would affect lymphocyte migration. (C) 1996 Academic Press, Inc.