Sodium restriction prevents cardiac hypertrophy and oxidative stress in angiotensin II hypertension.

The influence of a low-sodium (LS) diet was assessed on the cardiac and renal alterations and pro-oxidant effect associated with a 10-day infusion of angiotensin II (200 or 400 ng. kg(-1). min(-1), osmotic pumps). Tail-cuff pressure (TCP), albuminuria, and renal blood flow were determined at the end of the experiments. Heart weight index (HWI) and production of superoxide anion (O(2)(-).) by the left ventricle and H(2)O(2) by the aorta was measured with the use of bioluminescence. Although the final TCP was similar in LS and normal sodium (NS) rats infused with high and low doses of angiotensin II, respectively, the increase in HWI was prevented by the LS diet. Sodium restriction reduced the rise in albuminuria without a change in the renal effect of angiotensin II. The increased production of O(2)(-). and H(2)O(2) observed in NS rats was abrogated in LS rats. The beneficial influence of dietary sodium restriction on target organ damage induced by angiotensin II is independent of arterial pressure reduction and possibly related to attenuation of the prooxidant effect of the peptide.