Oxidative stress in Dahl salt-sensitive hypertension.
The role of oxidative stress in the long-term regulation of arterial pressure, renal hemodynamics, and renal damage was studied in Dahl salt-sensitive rats. Twenty-eight Dahl S/Rapp strain rats, equipped with indwelling arterial and venous catheters, were subjected to a 3-week intravenous infusion of either low Na (0.9 mmol/d) or high Na (20.6 mmol/d) or the superoxide dismutase mimetic, 4-hydroxyl-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol), at 125 micromol x kg(-1) x h(-1) plus low Na or high Na. After 21 days, mean arterial pressure was 140+/-3 mm Hg in the high-Na group, 118+/-1 mm Hg (P<0.05) in the high-Na/Tempol group, and unchanged in the low-Na/Tempol and low-Na groups. Tempol did not change renal blood flow, glomerular filtration rate, or glomerular cross-sectional area in rats subjected to the high-Na intake but did decrease urinary protein excretion, the percentage of sclerotic glomeruli, and the kidney weight to body weight ratio. In 15 additional Dahl S rats subjected to high or low Na intake for 3 weeks, renal cortical and medullary O2*- release increased significantly in the high-Na group when compared with the low-Na group. Tempol decreased both renal cortical and medullary O2*- release in the high- and low-Na rats, but the decrease in O2*- release was greater in high-Na rats. The data suggest that oxidative stress contributes to Dahl salt-sensitive hypertension and the accompanying renal damage.
Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, USA.
Shumei
S
Meng
Garrick W
GW
Cason
Anthony W
AW
Gannon
Lorraine C
LC
Racusen
R Davis
RD
Manning
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003497:Cyclic N-Oxides / Q000008:administration & dosage / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D006973:Hypertension / Q000209:etiology* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D007262:Infusions, Intravenous; D007668:Kidney / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D007678:Kidney Glomerulus / Q000473:pathology; D008297:Male; D018384:Oxidative Stress; D011507:Proteinuria / Q000175:diagnosis; D051381:Rats; D020303:Rats, Inbred Dahl; D012598:Sclerosis; D012964:Sodium / Q000652:urine; D013113:Spin Labels; D013481:Superoxides / Q000378:metabolism; D014556:Urine
D003497:Cyclic N-Oxides; D013113:Spin Labels; D013481:Superoxides; D012964:Sodium; C001803:tempol