Effect of chronic renal medullary nitric oxide inhibition on blood pressure.
The effects of chronic nitric oxide inhibition in the renal medulla on renal cortical and medullary blood flow, sodium balance, and blood pressure were evaluated in conscious uninephrectomized Sprague-Dawley rats. During a 5-day renal medullary interstitial infusion of the nitric oxide inhibitor NG-nitro-L-arginine methyl ester (L-NAME, 120 micrograms/h) in saline (0.5 ml/min), renal medullary blood flow was selectively decreased by 30% after 2 h and was maintained at that level for the entire infusion. The decrease in medullary blood flow was associated with sodium retention and increased blood pressure. After the cessation of L-NAME infusion, medullary blood flow returned to control, and the sodium balance became negative as blood pressure returned to baseline. These data indicate that renal medullary nitric oxide plays an important role in the regulation of renal blood flow, sodium excretion, and blood pressure.
Mattson
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DL
Department of Physiology, Medical College of Wisconsin, Milwaukee 53226.
Lu
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Nakanishi
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K
Papanek
P E
PE
Cowley
A W
AW
D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D007263:Infusions, Parenteral; D007275:Injections, Intravenous; D007672:Kidney Cortex / Q000098:blood supply*; D007679:Kidney Medulla / Q000098:blood supply* / Q000187:drug effects; D019331:NG-Nitroarginine Methyl Ester; D009392:Nephrectomy; D009569:Nitric Oxide / Q000037:antagonists & inhibitors*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D012079:Renal Circulation / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors
D009569:Nitric Oxide; D001120:Arginine; D019331:NG-Nitroarginine Methyl Ester