TWEEN-80 AND ENDOTHELIUM - FUNCTIONAL REDUCTION DUE TO TISSUE-DAMAGE

The effects of Tween 80, a surface active agent which is frequently us ed for dispersion of water-insoluble subtances, on endothelial functio n in rabbit aorta were investigated in a cascade superfusion bioassay system by using a deendothelized precontracted rat aorta ring as a bio assay tissue. Prior incubation of rabbit thoracic aorta segments with higher concentrations of Tween XD, caused total inhibition of acetylch oline-induced endothelium derived relaxing factor (EDRF) release, whil e moderate concentrations had no significant effect. Perfusion of the donor aortae segments with 10(-1)-10(-3) ml/l Tween 80 also inhibited the EDRF release from donor aorta dose-dependently. Histopathological examination of the vasculary wall and endothelial structures revealed a significant desquamation of vasculary endothelium with the highest c oncentration of Tween 80 used in this study. These data suggest that t he mechanism underlying the reduction in the release of EDRF from dono r aorta segments may be the destruction by Tween 80 of endothelial lin ing.