<prompt> NO is synthesized by all except -EndotheliumNeuronMacrophagesPlatelets  <response>: Plateletso 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 2Qo NO synthase is a very complex enzyme, employing five redox cofactors: NADPH, FAD, FMN, heme, and tetrahydrobiopterin Q . 