Attenuated afferent arteriolar response to acetylcholine in goldblatt hypertension

Joseph M. Ortenberg, Anthony K. Cook, Edward W. Inscho, Pamela K. Carmines

Research output: Contribution to journalArticle

7 Scopus citations

Abstract

We tested the hypothesis that endothelium-dependent afferent arteriolar vasodilation is impaired in the nonclipped kidney of two-kidney, one clip Goldblatt hypertensive rats relative to sham-operated controls. Five to six weeks after positioning of a 0.25-mm clip on the left renal artery, systolic pressure averaged 173±10 mm Hg in Goldblatt rats and 118±4 mm Hg in controls (p < 0.01). The right kidney was harvested for videometric study of the microvasculature using the in vitro blood-perfused juxtamedullary nephron technique. Kidneys from Goldblatt and control rats were perfused at renal arterial pressures of 150 and 110 mm Hg, respectively. Afferent arteriolar inside diameter did not differ between control (20.3±0.7 μm) and Goldblatt (21.1±1.7 μm) kidneys. Determination of afferent responses to increasing concentrations of the endothelium-dependent vasodilator acetylcholine (1 nM to 10 μM) in the bathing solution unveiled a shift to the right in the dose-response relation in Goldblatt rats. Afferent arterioles from control kidneys dilated significantly when exposed to 1 nM acetylcholine, whereas a 1,000-fold higher concentration was required to dilate arterioles from Goldblatt rats. Sodium nitroprusside, an endothelium-independent vasodilator, increased afferent diameter to a similar extent in both groups. In a separate group of normal kidneys, vasodilator responses to 10 μM acetylcholine were completely blocked by 1,000 μM nitro-L-arginine, an inhibitor of nitric oxide synthesis. Thus, endothelium-dependent afferent vasodilation appears to be impaired in the nonclipped kidney of Goldblatt hypertensive rats. This phenomenon could contribute to the altered renal hemodynamic status characteristic of Goldblatt hypertension.

Original languageEnglish (US)
Pages (from-to)785-789
Number of pages5
JournalHypertension
Volume19
Issue number6
DOIs
StatePublished - Jun 1992

Keywords

  • Goldblatt hypertension
  • acetylcholine
  • microcirculation
  • nitroprusside
  • vasodilation

ASJC Scopus subject areas

  • Internal Medicine

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