FIG. 3.

Nitric oxide and platelet aggregation. Nitric oxide donors, including nitroglycerin (TNG), S-nitrosothiols (RSNOs), and sodium nitroprusside (SNP), or endothelium-derived NO^• inhibit agonist-induced platelet aggregation by increasing platelet cGMP levels; decreasing expression of the fibrinogen receptor GPIIb/IIIa, P-selectin, and CD63; and inhibiting PI3-kinase activation, to limit irreversible platelet aggregation. Platelet-derived NO^•, in turn, inhibits the recruitment of circulating platelets to sites of vascular injury. vWF, von Willebrand factor. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article at www.liebertonline.com/ars).