Manifestation of oxidative stress in the pathogenesis of arterial hypertension in ISIAH rats

The ISIAH rat strain with stress-sensitive arterial hypertension was intent ionally selected to study the role of stress as a factor in the development of arterial hypertension. This study aimed to determine the role of reacti ve oxygen and nitrogen species (ROS and RNS) in the pathogenesis of hyperte nsion in ISIAH rats. The nitric oxide concentrations measured by EPR were f ound to be significantly higher for hypertensive ISIAH rats compared with t hat for normotensive Wistar rats in both the aortic wall (2 times) and cere bellum (1.5 times). The activity of superoxide dismutase measured in the bl ood of ISIAH rats was found to be about 1.5 times lower compared with that of Wistar rats. These data support the suggestion that ROS and RNS, includi ng superoxide radicals and nitric oxide, may play an important role in deve lopment of stress-induced hypertension in ISIAH rats. The tissue content of reduced thiols has been considered as a marker of oxidative damage. To stu dy the tissue oxidative status we used an EPR method for quantitative deter mination of SH groups. The concentration of reduced thiols in the blood of ISIAH rats was much lower than that in Wistar rats (0.6 +/- 0.05 and 1.57 /- 0.1 mM, respectively). (C) 1999 Academic Press.