Inorganic nitrate: a game changer in preventing contrast-associated acute kidney injury

Graphical AbstractOpen in new tabDownload slideContrast agent acute kidney injury (CA-AKI) is characterized by high levels of oxidative stress, an alteration that impairs vasodilatory mechanism(s) in the renal microcirculation at the glomerular level and other kidney vessels and that causes tubular damage. ROS concentrations [including superoxide anion (O2−), hydrogen peroxide (H2O2), hydroxyl radical (·OH), and singlet oxygen (1O2) and other reactive species] are high in CA-AKI and reduce the amount of bioactive nitric oxide (NO) by chemical inactivation to form toxic peroxynitrite. In turn, peroxynitrite uncouples endothelial NO synthase to become a dysfunctional superoxide-generating enzyme, thereby further aggravating oxidative stress. Exogenous inorganic nitrates, via transformation into nitrites, are a powerful source of NO, which effectively restores vasoregulatory mechanisms and reverses kidney damage.