Korean J Nephrol.  2006 Jul;25(4):525-531.

Effects of Tempol on Blood Pressure and Tissue Oxidative Stress in DOCA-alt and L-AME-nduced Hypertension

• Cho YW
• Cho JW
• Bae EH
• Kim SW
• Ma SK
• Choi KC
• Lee J

Abstract

BACKGROUND: Effects of oxidative stress on the development of deoxycorticosterone acetate (DOCA)-salt or N(G)-nitro-L-arginine (L-NAME) hypertension were examined.
METHODS
Male Sprague-awley rats were treated with DOCA (200 mg/kg, subcutaneous)-salt or L-NAME (40 mg/L in daily drinking water) for 4 weeks. To reduce the oxidative stress, 4-hydroxyl-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol, 3 mM/L) was cotreated in drinking water. The expression of endothelial nitric oxide synthase (eNOS) and nitrotyrosine proteins was determined in the renal cortex and thoracic aorta.
RESULTS
Tempol prevented the development of DOCA-salt hypertension, whereas it was without effect on L-NAME hypertension. In DOCA-salt hypertension, the eNOS expression in the renal cortex was increased, the degree of which was attenuated by Tempol. The renal expression of nitrotyrosine was decreased, which was further decreased by Tempol. In the aorta, the expression of both eNOS and nitrotyrosine was decreased, which was not further affected by Tempol. In L-NAME hypertension, the renal expression of eNOS was significantly increased, which was blocked by Tempol. The expression of eNOS in the aorta was slightly decreased, and was not further affected by Tempol. The renal expression of nitrotyrosine was not significantly altered. However, its expression was significantly decreased in the aorta, and was further reduced by Tempol.
CONCLUSION
The blockade of oxidative stress may attenuate the development of hypertension and provide tissue protection in DOCA-salt hypertension. The blockade of oxidative stress may also contribute to a tissue protection in L-NAME hypertension.

Keyword

Hypertension; Tempol; Nitric oxide synthase; Nitrotyrosine

MeSH Terms

Animals
Aorta
Aorta, Thoracic
Blood Pressure*
Desoxycorticosterone
Desoxycorticosterone Acetate
Drinking
Drinking Water
Humans
Hypertension*
Male
NG-Nitroarginine Methyl Ester
Nitric Oxide Synthase
Nitric Oxide Synthase Type III
Oxidative Stress*
Rats
Desoxycorticosterone
Drinking Water
NG-Nitroarginine Methyl Ester
Nitric Oxide Synthase
Nitric Oxide Synthase Type III