NOS3 and endothelial dysfunction: Several mechanisms leading to endothelial dysfunction, such as a lack of enzymatic cofactors for eNOS (Mangge et al., 2014), the inactivation of NO by the reaction of superoxide (O2-) resulting in peroxynitrite anion (OONO-) formation (Pacher et al., 2007), the influence of superoxide NADPH oxidase (Griendling et al., 2000) and “uncoupled” eNOS, have been demonstrated (Figure 1).