NO is synthesized by all except -

Platelets o Three isoforms of NO synthase have been identified Neuronal NOS (nNOS or NOS-1); (ii) Macrophage or inducible NOS (iNOS orNOS-2); and (Hi) Endothelial NOS (eNOS or NOS-3). NOS-1 and NOS-3 are constitutive enzymes, whereas NOS2 is inducible in inflammatory' conditions. o NOS-1 and NOS-3 are activated by Ca +2Q o NO synthase is a very complex enzyme, employing five redox cofactors: NADPH, FAD, FMN, heme, and tetrahydrobiopterin Q .