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Coronary endothelial dysfunction is not rapidly reversible with ascorbic acid. Free Radic Biol Med 2004 Jan 01;36(1):123-30

Date

01/21/2004

Pubmed ID

14732296

DOI

10.1016/j.freeradbiomed.2003.10.016

Scopus ID

2-s2.0-0347948558   7 Citations

Abstract

In humans with cardiovascular risk factors, increased vascular production of superoxide anion may contribute to endothelial dysfunction by its reacting with nitric oxide and reducing its biological activity. High concentrations of ascorbic acid scavenge superoxide anion and restore normal endothelium-dependent vasodilation in humans with cardiovascular risk factors. To investigate the contribution of increased superoxide anion to endothelial dysfunction in atherosclerotic coronary arteries, we examined the effect of sequential infusions of ascorbic acid (final concentration 0.1, 1.0, and 10 mmol/L) or placebo on coronary endothelial function in 26 subjects referred for cardiac catheterization to evaluate coronary artery disease. Coronary vasomotor function was evaluated using intracoronary agonist infusion, quantitative angiography, and intracoronary Doppler measurements. At baseline, endothelium-dependent vasodilation of epicardial arteries and coronary microvessels was impaired to an equivalent extent in the ascorbic acid and placebo groups. Sequential ascorbic acid infusions had no effect on the acetylcholine-induced change in coronary artery diameter (-11+/-8, -12+/-10, and -9+/-9%) compared with the effect of placebo (-14+/-13, -16+/-10, and -13+/-9%) infusions (p=0.98). Similarly, the changes in coronary blood flow during acetylcholine infusions were equivalent during ascorbic acid (51+/-44, 67+/-66, and 62+/-52%) and placebo (61+/-104, 55+/-93, and 50+/-69%) infusions (p=0.63). Ascorbic acid also had no effect on the dilator response to intracoronary nitroglycerin (p=0.19). These data argue against an important role for superoxide-mediated "inactivation" of nitric oxide or another rapidly reversible form of oxidative stress as a mechanism of coronary endothelial dysfunction in patients with coronary atherosclerosis.

Author List

Widlansky ME, Biegelsen ES, Hamburg NM, Duffy SJ, Keaney JF Jr, Vita JA

Author

Michael E. Widlansky MD Associate Director, Professor in the Medicine department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Acetylcholine
Ascorbic Acid
Coronary Disease
Coronary Vessels
Endothelium, Vascular
Female
Humans
Male
Middle Aged
Vasomotor System
jenkins-FCD Prod-484 8aa07fc50b7f6d102f3dda2f4c7056ff84294d1d