NITROPRUSSIDE HAS NO EFFECT ON T-PA AND PAI PRODUCTION AND RELEASE BYENDOTHELIAL-CELLS IN CULTURE

In this study we examined the influence of sodium nitroprusside (SNP) on the fibrinolytic activity of human umbilical venous endothelial cel ls (HUVEC) and platelets. SNP (1-100 uM) was not able to modify tissue type plasminogen activator (t-PA) and its specific inhibitor (PAI-I) production by cultured endothelial cells. As already known, SNP dose-d ependently inhibited platelet aggregation in response to several agoni sts. However, platelet PAI release measured during stimulation in the presence of SNP was not affected, even at concentrations of SNP able t o block aggregation. Our data demonstrate that SNP has no effect on t- PA, and PAI production and release by human endothelial cells in cultu re, moreover, SNP does not affect PAI release from platelets in vitro.