Platelet adhesion to XXXX vascular endothelium is modulated by constitutive and cytokine induced @entity842 .

@entity1 @entity7792 @entity1356 @entity310 @entity5 @entity1423 @entity534 @entity619 @entity7293 @entity842 @entity3623
OBJECTIVE: The aim was to study whether basal or cytokine stimulated generation of @entity842 (NO) modulates platelet adhesion to @entity1 umbilical vein endothelial cells (HUVEC). METHODS: The adhesion of 111In labelled @entity1 platelets to transfected HUVEC (SGHEC-7) was measured either alone or after incubation of SGHEC-7 cells for 18 h with @entity1356 ( @entity1356 ) and/or @entity5 necrosis factor alpha ( @entity310 ). The activity of NO synthase in these cells was measured by formation of @entity7792 . The effects of @entity619 (0.3 microM) and @entity7293 ( @entity7293 , 100 microM) on these two variables were determined. RESULTS: Stimulation of SGHEC-7 cells with @entity1356 or @entity310 (each at 1-30 ng.ml-1) caused them to express the @entity3623 , an effect that was prevented by @entity619 . Platelet adhesion to unstimulated SGHEC-7 cells was < 0.1% (n = 3) and was increased to 0.7 (SEM 0.2)% by @entity7293 but was not affected by @entity619 . Stimulation of the cells with @entity1356 and @entity310 @entity1423 to a maximum of 2.2(0.4)%. This increase was enhanced by both @entity619 and @entity7293 . The effect of @entity7293 was prevented by @entity534 . CONCLUSIONS: Inhibition of NO synthesis by @entity7293 potentiates platelet adhesion to unstimulated SGHEC-7 cells, showing that basally released NO regulates platelet adhesion. Stimulation of SGHEC-7 cells by cytokines increases their adhesive properties but at the same time causes them to express the @entity3623 . @entity842 generated by this enzyme contributes to the modulation of the adhesive properties of the endothelial cells. Thus both constitutive and inducible NO synthases modulate endothelial cell thrombogenicity.
