Oxidative Stress and Vascular Damage in Hypertension: Role of Angiotensin II
Figure 1
Hypothetic involvement of cyclooxygenase (COX) isoforms in angiotensin II- (AngII-) induced endothelial dysfunction. Ang II promotes reactive oxygen species (ROS) generation by vascular NAD(P)H oxidase activation. ROS rapidly react with nitric oxide (NO), leading to reduce its availability and to produce peroxynitrites (ONOOā). Ang II might also directly downregulate COX-2 or upregulate COX-1. COX-1 is also activated by acetylcholine. Under such conditions, ROS stimulate COX-1 to transform arachidonic acid into endoperoxides, which in turn activate the contracting thromboxane-prostanoid (TP) receptors.
