An enzyme that catalyzes the reaction which the body utilizes to make nitric oxide from L-arginine (via cleavage, off that molecule). The cofactor for that reaction is nicotine-adenine dinucleotide phosphate (NADP).
An enzyme that synthesizes nitric oxide from arginine; present in the central nervous system, the lining of blood vessels, the heart, joints, some autonomic neurons, and other organs.