Figure 1From: Endothelial nitric oxide synthase, vascular integrity and human exceptional longevitya) Representative nitric oxide pathway. b) Effects of aging on nitric oxide pathway. BH4 = tetrahydrobiopterin; Ca2+ = calcium ion; cGMP = cyclic guanosine monophosphate; eNOS = endothelial nitric oxide synthase; GTP = guanosine triphosphate; NADPH = nicotinamide adenine dinucleotide phosphate; NO = nitric oxide; ONOO- = Peroxynitrite; ADMA = Dimethylarginine; ROS = reactive oxygen species.Back to article page