NO is secreted by-

Also called as Endothelium derived Relaxing Factor NO (nitric oxide):- synthesized from Arginine by enzyme NOS (Nitric oxide synthase) in the endothelial cells Nitric oxide relaxes the smooth muscles of blood vessels The vasodilator - nitroglycerin also enters smooth muscle cells, where its metabolism also leads to the formation of NO. Activates enzyme Guanyl cyclase, which conves GTP to cyclic GMP, which causesrelaxation of smooth muscle cells OTHER FREQUENTLY ASKED QUESTIONS ON NITRIC OXIDE There are three isoforms of NOS (Nitric oxide synthase) a) nNOS - neuronal b) iNOS- inducible c) eNOS- endothelial