Antioxidant Treatment Reduces Blood Pressure in Hypertensive Rats
This research article begins to link reactive oxygen species (ROS) to increased blood pressure. ROS are formed normally in the body by the process of making energy, and the body normally gets rid of these rapidly using antioxidants. However, if too many ROS are being produced and/or not enough antioxidants are present, oxidative stress occurs. The ROS then work to lower levels of nitric oxide, a substance that relaxes blood vessels. The bottom line: eats lots of fresh fruits, veggies and take additional antioxidants.
Hypertension 2000;36:957-964 Reactive oxygen species (ROS) appear to upregulate the expression of nitric oxide synthase (NOS) isoforms in spontaneously hypertensive rats, and the effect can be reversed by treatment with an antioxidant, according to researchers from the University of California, Irvine. Dr. Nosratola D. Vaziri and colleagues note that spontaneously hypertensive rats have increased ROS, increased NOS expression, and increased NO production. They suggest that ROS may inactivate NO, leading to increased NOS expression through negative feedback regulation of NOS by NO. Lazaroid treatment of hypertensive rats reversed the increase of endothelial and inducible NOS in vascular, renal, and cardiac tissues, but had a minimal effect on the levels of renal and brain neuronal NOS. Lazaroid had limited effect on blood pressure, the expression of NOS isotypes, or urinary nitrate and nitrite excretion. The results “support the role of oxidative stress in the genesis and/or maintenance of hypertension and compensatory upregulation of the expression of endothelial NOS and inducible NOS in spontaneously hypertensive rats,” Dr. Vaziri and colleagues conclude.