L-arginine administration normalizes pressure natriuresis in hypertensive Dahl rats.
A blunted pressure-natriuretic response characterizes hypertension in the Dahl salt-sensitive rat. Long-term L-arginine administration prevents hypertension in these animals. To determine if long-term L-arginine corrects the pressure-natriuretic response, we gave salt-sensitive rats on an 8% sodium diet L-arginine or vehicle daily for 3 weeks. Identically treated salt-resistant rats served as controls. After 3 weeks, acute pressure-natriuresis curves were determined. To control for hypertension-induced renal damage, we also examined pressure natriuresis in salt-sensitive rats after short-term L-arginine. Baseline mean arterial pressure was 158 +/- 3 mm Hg in vehicle-treated salt-sensitive rats and 127 +/- 3 mm Hg in chronically L-arginine-treated salt-sensitive rats. During alterations in perfusion pressure, renal blood flow was autoregulated in all groups. Glomerular filtration rate was autoregulated in salt-resistant rats and L-arginine-treated salt-sensitive rats but fell with decreasing pressure in vehicle-treated salt-sensitive rats. Sodium excretion was greater (P < .05) in L-arginine-treated than in vehicle-treated salt-sensitive rats and did not differ from salt-resistant rats at 100, 125, and 158 mm Hg. The slope of the pressure-natriuresis relation was greater (P < .05) in chronically L-arginine-treated than in vehicle-treated salt-sensitive rats. L-Arginine had no effect on natriuresis in salt-resistant rats. Thus, long-term L-arginine administration normalizes pressure-natriuretic responses in salt-sensitive rats. The effect is not due to the prevention of renal damage and is specific to the salt-sensitive strain.(ABSTRACT TRUNCATED AT 250 WORDS)
Patel
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Department of Medicine, University of Mississippi Medical Center, Jackson 39216-4505.
Layne
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Watts
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Kirchner
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KA
D000704:Analysis of Variance; D000818:Animals; D001120:Arginine / Q000494:pharmacology* / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects*; D004195:Disease Models, Animal; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006973:Hypertension / Q000517:prevention & control*; D007444:Inulin / Q000097:blood / Q000652:urine; D007668:Kidney / Q000187:drug effects; D008297:Male; D009318:Natriuresis / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D012079:Renal Circulation / Q000187:drug effects; D012964:Sodium / Q000097:blood / Q000652:urine; D012982:Sodium, Dietary / Q000008:administration & dosage / Q000493:pharmacokinetics
D012982:Sodium, Dietary; D007444:Inulin; D001120:Arginine; D012964:Sodium