Endothelial cells influence the sodium nitroprusside mediated inhibition of platelet aggregation by an as yet unkown pathway.

Unlabelled: The clinical use of Sodium nitroprusside (SNP) may be associated with an alteration of platelet function. The main focus of this study was the effect of SNP on platelet aggregation in the absence or presence of endothelial cells.

Methods: Platelets were incubated with different concentrations of SNP with and without endothelial cells.

Endothelial cells play an important role in the antiaggregatory effect of nitric oxide.

Objective: To investigate the role of endothelial cyclooxygenase in the antiaggregatory effect of nitric oxide, and to investigate the significance of the time span between contact of nitric oxide and platelets and laboratory evaluation by platelet aggregation.

Design: Prospective, controlled, in vitro study.

Setting: Research laboratory of a university hospital.