Figure 1From: Is type 2 diabetes mellitus a vascular disease (atheroscleropathy) with hyperglycemia a late manifestation? The role of NOS, NO, and redox stress.Oxygen reacts with the eNOS enzyme in which the BH4 cofactor has coupled NAD(P)H with L-arginine to be converted to NO and L-citrulline. When uncoupling occurs the NAD(P)H reacts with O2 and the endothelial cell becomes a net producer of superoxide (O2').Back to article page