Abstract | BACKGROUND: Blocked glycogen breakdown in McArdle disease impairs oxidative as well as anaerobic metabolism, but the contribution of impaired oxidative phosphorylation to everyday symptoms of McArdle disease remains poorly defined. OBJECTIVE: To evaluate the oxidative implications of the spontaneous second wind and variables that influence the development of this typical feature of McArdle disease. DESIGN: Assessment of exercise and oxidative capacity (.VO(2)) before and after the spontaneous "second wind" and with a glucose infusion after a spontaneous second wind. PATIENTS: MAIN OUTCOME MEASURES: Work capacity,.VO(2), heart rate, cardiac output. RESULTS: All patients with complete myophosphorylase deficiency (1) had low peak.VO(2) (mean +/- SD, 13.0 +/- 2.0 mL. kg(-1). min(-1)) in the first 6 to 8 minutes of exercise; (2) achieved a spontaneous second wind with increased exercise capacity between 8 and 12 minutes of exercise due to a more than 25% increase in peak.VO(2) (16.5 +/- 3.1 mL. kg(-1). min(-1)); and (3) with glucose infusion after a spontaneous second wind, experienced a further more than 20% increase in oxidative capacity (.VO(2), 19.9 +/- 3.9 mL. kg(-1). min(-1)). In the patient with residual myophosphorylase,.VO(2) (22.2 mL. kg(-1). min(-1)) in the first 6 to 8 minutes of exercise was approximately 2-fold higher than the mean of patients lacking myophosphorylase, and no significant improvement in exercise and oxidative capacity accompanied prolonged exercise or glucose infusion. CONCLUSIONS:
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Authors | Ronald G Haller, John Vissing |
Journal | Archives of neurology
(Arch Neurol)
Vol. 59
Issue 9
Pg. 1395-402
(Sep 2002)
ISSN: 0003-9942 [Print] United States |
PMID | 12223025
(Publication Type: Clinical Trial, Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)
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Chemical References |
- Lactic Acid
- Glycogen Phosphorylase, Muscle Form
- Glucose
- Oxygen
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Topics |
- Adult
- Anaerobic Threshold
(physiology)
- Cardiac Output
(physiology)
- Exercise
(physiology)
- Female
- Glucose
(pharmacology)
- Glycogen Phosphorylase, Muscle Form
(deficiency)
- Glycogen Storage Disease Type V
(metabolism)
- Heart Rate
(physiology)
- Humans
- Lactic Acid
(blood)
- Male
- Oxidation-Reduction
- Oxygen
(blood)
- Oxygen Consumption
(physiology)
- Work Capacity Evaluation
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