Abstract:
Oxidative stress is an imbalance between free radicals and
antioxidants, and is an important etiological factor in the
development of hypertension. Recent experimental evidence
suggests that subpressor doses of angiotensin II elevate
oxidative stress and blood pressure. We aimed to investigate the
oxidative stress related mechanism by which a subpressor dose
of angiotensin II induces hypertension in a normotensive rat
model. Normotensive male Wistar rats were infused with a
subpressor dose of angiotensin II for 28 days. The control group
was sham operated and infused with saline only. Plasma
angiotensin II and H2O2 levels, whole-blood glutathione
peroxidase, and AT-1a, Cu/Zn SOD, and p22phox mRNA
expression in the aorta was assessed. Systolic and diastolic blood
pressures were elevated in the experimental group. There was no
change in angiotensin II levels, but a significant increase in AT-
1a mRNA expression was found in the experimental group. mRNA
expression of p22phox was increased significantly and Cu/Zn
SOD decreased significantly in the experimental group. There was no significant change to the H2O2 and GPx levels.
Angiotensin II manipulates the free radical-antioxidant balance in
the vasculature by selectively increasing O2
− production and
decreasing SOD activity and causes an oxidative stress induced
elevation in blood pressure in the Wistar rat.
