PathwayStep528 PathwayStep527 PathwayStep526 PathwayStep533 Soluble guanylate cyclase converts GTP to cGMP Nitric Oxide Synthase (NOS) produces Nitric Oxide (NO) NO binds to Guanylate Cyclase Nitric oxide stimulates guanylate cyclase Authored: Akkerman, JW, 2009-06-03 Edited: Jupe, S, 2010-06-07 Nitric Oxide (NO) inhibits smooth muscle cell proliferation and migration, oxidation of low-density lipoproteins, and platelet aggregation and adhesion. It can stimulate vasodilatation of the endothelium, disaggregation of  preformed platelet aggregates and inhibits activated platelet recruitment to the aggregate. NO is synthesized from L-arginine by a family of isoformic enzymes known as nitric oxide synthase (NOS). Three isoforms, namely endothelial, neuronal, and inducible NOS (eNOS, nNOS, and iNOS, respectively), have been identified. The eNOS isoform is found in the endothelium and platelets. NO regulation of cyclic guanosine-3,5-monophosphate (cGMP), via activation of soluble guanylate cyclase, is the principal mechanism of negative control over platelet activity. Defects in this control mechanism have been associated with platelet hyperaggregability and associated thrombosis. Pubmed12881475 Pubmed16319917 Pubmed18327704 Reactome Database ID Release 43392154 Reactome, http://www.reactome.org ReactomeREACT_23862 Reviewed: Kunapuli, SP, 2010-06-07 cGMP effects