To assess the antioxidant effects of atorvastatin (atorva) on dexamethasone (dex)-induced hypertension, 60 male Sprague-Dawley rats were treated with atorva 30 mg/kg/day or tap water for 15 days. Dex increased systolic blood pressure (SBP) from 109 +/- 1.8 to 135 +/- 0.6 mmHg and plasma superoxide (5711 +/- 284.9 saline, 7931 +/- 392.8 U/ml dex, P < 0.001). In this prevention study, SBP in the atorva + dex group was increased from 115 +/- 0.4 to 124 +/- 1.5 mmHg, but this was significantly lower than in the dex-only group (P' < 0.05). Atorva reversed dex-induced hypertension (129 +/- 0.6 mmHg, vs. 135 +/- 0.6 mmHg P' < 0.05) and decreased plasma superoxide (7931 +/- 392.8 dex, 1187 +/- 441.2 atorva + dex, P < 0.0001). Plasma nitrate/nitrite (NOx) was decreased in dex-treated rats compared to saline-treated rats (11.2 +/- 1.08 microm, 15.3 +/- 1.17 microm, respectively, P < 0.05). Atorva affected neither plasma NOx nor thymus weight. Thus, atorvastatin prevented and reversed dexamethasone-induced hypertension in the rat.