| Skeletal muscle lactate accumulation and creatine phosphate depletion during heavy exercise in congestive heart failure. Cause of limited exercise capacity? | |
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MedLine Citation:
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PMID: 9447322 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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OBJECTIVE: To study the mechanisms of limited exercise capacity and skeletal muscle energy production in male patients with congestive heart failure. DESIGN: Muscle biopsy study. PATIENTS: Skeletal muscle metabolic response to maximal bicycle exercise was studied in 10 patients with chronic congestive heart failure (ejection fraction 0.22 +/- 0.05; peak oxygen consumption, VO2 15.1 +/- 4.9 ml.min-1.kg-1) and in nine healthy subjects (peak VO2 33.5 +/- 6.7 ml.min-1.kg-1). Activities of skeletal muscle enzymes were measured from the vastus lateralis muscle of 48 patients (ejection fraction 0.24 +/- 0.06, peak VO2 17.4 +/- 5.4 ml.min-1.kg-1) and 36 healthy subjects (peak VO2 38.3 +/- 8.4 ml.min-1.kg-1). RESULTS: Although blood lactate levels were lower in patients than in healthy subjects (2.2 +/- 0.3 vs 5.2 +/- 0.6 mmol.l-1; P < 0.001) at peak exercise (96 +/- 11 W for patients and 273 +/- 14 W for controls), skeletal muscle lactate was similarly elevated (25.6 +/- 3.2 vs 22.7 +/- 2.7 mmol.kg-1) and creatine phosphate was equally depressed (P < 0.02) to low levels (7.0 +/- 1.9 vs 6.7 +/- 0.9 mmol.kg-1). The muscle ATP decreased by 21% (P < 0.05) and 8% (P < 0.01) in the patients and controls, respectively. Activities of rate limiting enzymes of the citric acid cycle (alpha-ketoglutarate dehydrogenase) and oxidation of free fatty acids (carnitine palmitoyltransferase II) were 48% and 21% lower than in controls, but the mean phosphofructokinase activity was unchanged in congestive heart failure. CONCLUSIONS: It seems that the main limiting factor of exercise performance during heavy exercise is the same in congestive heart failure and healthy subjects, a high rate of skeletal muscle lactate accumulation and high-energy phosphate depletion. In congestive heart failure, the low activity of aerobic enzymes is likely to impair energy production and lead to lactate acidosis at low workloads. |
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Authors:
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H K Näveri; H Leinonen; K Kiilavuori; M Härkönen |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: European heart journal Volume: 18 ISSN: 0195-668X ISO Abbreviation: Eur. Heart J. Publication Date: 1997 Dec |
Date Detail:
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Created Date: 1998-03-18 Completed Date: 1998-03-18 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 8006263 Medline TA: Eur Heart J Country: ENGLAND |
Other Details:
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Languages: eng Pagination: 1937-45 Citation Subset: IM; S |
Affiliation:
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Department of Medicine, Helsinki University Central Hospital, Finland. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adenosine Triphosphate
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analysis Adult Chronic Disease Epinephrine / blood Exercise / physiology* Exercise Test Exercise Tolerance / physiology* Heart Failure / metabolism* Humans Lactates / metabolism* Male Middle Aged Muscle, Skeletal / chemistry, metabolism* Norepinephrine / blood Phosphocreatine / analogs & derivatives, analysis |
| Chemical | |
Reg. No./Substance:
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0/Lactates; 51-41-2/Norepinephrine; 51-43-4/Epinephrine; 56-65-5/Adenosine Triphosphate; 5786-71-0/phosphocreatinine; 67-07-2/Phosphocreatine |
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