Role of nitric oxide in the control of the renal medullary circulation

David L. Mattson, Shanhong Lu, Allen W. Cowley

Research output: Contribution to journalArticle

39 Scopus citations

Abstract

1. Nitric oxide (NO) has been implicated as an important controller in the short- and long-term regulation of arterial pressure. Studies performed in our laboratory have demonstrated that chronic intravenous administration of the NO synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) selectively decreases renal medullary blood how causes sodium and water retention and leads to hypertension. 2. To determine the importance of the renal medullary effects in this model of hypertension, further studies were conducted to examine the influence of selective stimulation or inhibition of renal medullary NO on whole kidney function and cardiovascular homeostasis. With the use of a unique catheter to directly infuse into the renal medullary interstitial space, stimulation (bradykinin or acetylcholine) or inhibition (L-NAME) of renal medullary NO selectively increased or decreased renal medullary blood flow. 3. The changes in medullary flow in these experiments were associated with parallel changes in sodium and water excretion independent of alterations in renal cortical blood flow or glomerular filtration rate. 4. Studies were then undertaken to examine the long-term effects of selective NO inhibition in the renal medulla on cardiovascular homeostasis. Chronic infusion of L-NAME directly into the renal medullary interstitial space of uninephrectomized Sprague-Dawley rats led to a selective decrease in renal medullary blood flow that was sustained throughout the 5 day L-NAME infusion period. The decrease in medullary blood flow was associated with retention of sodium and the development of hypertension and the effects were reversible. 5. The data reviewed indicate that NO in the renal medulla has a powerful influence on fluid and electrolyte homeostasis and the control of blood pressure.

Original languageEnglish (US)
Pages (from-to)587-590
Number of pages4
JournalClinical and Experimental Pharmacology and Physiology
Volume24
Issue number8
DOIs
StatePublished - Jan 1 1997
Externally publishedYes

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Keywords

  • Hypertension
  • Laser-Doppler flowmetry
  • Nitric oxide
  • Renal haemodynamics
  • Renal medulla

ASJC Scopus subject areas

  • Physiology
  • Pharmacology
  • Physiology (medical)

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