Document Detail

Improvement of sympathetic response to exercise by oral administration of ascorbic acid in patients after myocardial infarction.
MedLine Citation:
PMID:  16246442     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Recent studies indicated that excessive oxidative stress in an animal heart failure model injures both the sympathetic nerve endings and receptors, resulting in disturbance of norepinephrine release and sensitivity to norepinephrine. However, it has not been clarified whether this phenomenon is expressed clinically in patients with heart disease. Therefore, we examined the efficacy of ascorbic acid administration as an antioxidant vitamin in relation to the heart rate and norepinephrine response to exercise in patients after myocardial infarction. METHODS: In this randomized crossover trial, 21 male patients who had had myocardial infarction underwent symptom-limited ergometer cardiopulmonary exercise testing twice, that is, without and with ascorbic acid (2 g) administration. Plasma norepinephrine concentrations were assessed at rest and at peak exercise, and heart rate responsiveness to the norepinephrine increment from rest to peak exercise (DeltaHR/logDeltaNE) was calculated. RESULTS: In the exercise test after ascorbic acid administration, peak oxygen consumption (VO(2)) improved over baseline. Ascorbic acid administration significantly increased the change in heart rate and norepinephrine from rest to peak exercise and DeltaHR/logDeltaNE. The increment in heart rate was significantly correlated with peak VO(2) in each test. CONCLUSION: Ascorbic acid intake before exercise improved exercise capacity through enhancement of the heart rate and norepinephrine response to exercise in patients after myocardial infarction. These findings suggest that ascorbic acid intake improves sympathetic dysfunction resulting from injury by excessive oxidative stress after myocardial infarction.
Kazuyo Kato; Nagaharu Fukuma; Yuko Kimura-Kato; Noriko Aisu; Takaya Tuchida; Kousuke Mabuchi; Teruo Takano
Publication Detail:
Type:  Journal Article; Randomized Controlled Trial     Date:  2005-10-21
Journal Detail:
Title:  International journal of cardiology     Volume:  111     ISSN:  0167-5273     ISO Abbreviation:  Int. J. Cardiol.     Publication Date:  2006 Aug 
Date Detail:
Created Date:  2006-07-31     Completed Date:  2007-01-04     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8200291     Medline TA:  Int J Cardiol     Country:  Ireland    
Other Details:
Languages:  eng     Pagination:  240-6     Citation Subset:  IM    
The First Department of Internal Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-8603, Japan.
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MeSH Terms
Ascorbic Acid / blood,  therapeutic use*
Cross-Over Studies
Exercise / physiology*
Exercise Test*
Heart Rate / drug effects*
Middle Aged
Myocardial Infarction / physiopathology,  therapy*
Norepinephrine / blood,  pharmacology
Oxygen Consumption / drug effects
Sympathetic Nervous System / drug effects,  physiopathology
Reg. No./Substance:
50-81-7/Ascorbic Acid; 51-41-2/Norepinephrine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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