The acute hemodynamic effect of an intravenous (IV) bolus of vanadate (10 μmol/kg bwt) followed by an IV infusion at 0.5 μmol/kg min was studied in Wistar rats at three different levels of Na intake: low Na+(0.5mEq/24 h), normal Na+(1.5 mEq/24 h), and high Na+(15 mEq/24 h). Hemodynamic changes were measured using the radioactive microsphere method. Vanadate decreased cardiac output by 52.0 ± 6.4% in low Na+rats, by 41.2 ± 3.3% in normal Na+, and by 29.2 ± 3.1% in high Na+group. Total peripheral resistances increased by 47.1 ± 26% in high Na+, group. Total peripheral resistances increased by 47.1 ± 26% in high Na+rats, by 80.1 ± 6.6% in normal Na+, and by 96.3 ± 4.5% in low Na+group. Renal blood flow decreased by 70 ± 4% in low Na+, 58 ± 3% in normal Na+, and 39 ± 3% in high Na+, Cerebral, testicular, and splanchnic blood flow showed smaller changes. These results demonstrate that intravenous vanadate induces marked hemodynamic changes that depend on Na+intake being more striking when the intake of sodium is reduced.