Oxidative stress and suppressed H 2 S production lead to increased renal vascular resistance, disturbed glomerular hemodynamics, and abnormal renal sodium and water handling, contribute to the pathogenesis and maintenance of essential hypertension in man and the spontaneously hypertensive rat. This study investigated the impact of H 2 S and tempol alone and in combination on blood pressure and renal hemodynamics and excretory functions in the SHR. Groups of WKY rats or SHR (n ¼ 6) were treated for 4 weeks either as controls or received NaHS (SHR + NaHS), tempol (SHR + Tempol), or NaHS plus tempol (SHR + NaHS + Tempol). Metabolic studies were performed on days 0, 14, and 28, thereafter animals were anaesthetized to measure renal hemodynamics and plasma oxidative and antioxidant markers. SHR control rats had higher mean arterial blood pressure (140.0 ± 2 vs. 100.0 ± 3 mmHg), lower plasma and urinary H 2 S, creatinine clearance, urine flow rate and urinary sodium excretion, and oxidative stress compared to WKY (all p50.05). Treatment either with NaHS or with tempol alone decreased blood pressure and oxidative stress and improved renal hemodynamic and excretory function compared to untreated SHR. Combined NaHS and tempol therapy in SHRs caused larger decreases in blood pressure ($20-22% vs. $11-15% and $10-14%), increases in creatinine clearance, urinary sodium excretion and fractional sodium excretion and up-regulated the antioxidant status compared to each agent alone (all p50.05). These findings demonstrated that H 2 S and tempol together resulted in greater reductions in blood pressure and normalization of kidney function compared with either compound alone.