| Importance of pH regulation and lactate/H+ transport capacity for work production during supramaximal exercise in humans. | |
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MedLine Citation:
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PMID: 17289910 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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We examine the influence of the cytosolic and membrane-bound contents of carbonic anhydrase (CA; CAII, CAIII, CAIV, and CAXIV) and the muscle content of proteins involved in lactate and proton transport [monocarboxylate transporter (MCT) 1, MCT4, and Na(+)/H(+) exchanger 1 (NHE1)] on work capacity during supramaximal exercise. Eight healthy, sedentary subjects performed exercises at 120% of the work rate corresponding to maximal oxygen uptake (W(max)) until exhaustion in placebo (Con) and metabolic alkalosis (Alk) conditions. The total (W(tot)) and supramaximal work performed (W(sup)) was measured. Muscle biopsies were obtained before and immediately after standardized exercises (se) at 120% W(max) in both conditions to determine the content of the targeted proteins, the decrease in muscle pH (DeltapH(m)), and the muscle lactate accumulation ([Lac](m)) per joule of W(sup) (DeltapH(m)/W(sup-se) and Delta[Lac](m)/W(sup-se), respectively) and the dynamic buffer capacity. In Con, W(sup) was positively [corrected] correlated with [corrected] MCT1, and tended to be positively correlated with MCT4 and NHE1. CAII + CAIII were correlated positively with DeltapH(m)/W(sup-se) and negatively with Delta[Lac](m)/W(sup-se), while CAIV was positively related to W(tot). The changes in W(sup) with Alk were correlated positively with those in dynamic buffer capacity and negatively with W(sup) in Con. Performance improvement with Alk was greater in subjects having a low content of proteins involved in pH regulation and lactate/proton transport. These results show the importance of pH regulating mechanisms and lactate/proton transport on work capacity and the role of the CA to delay decrease in pH(m) and accumulation in [Lac](m) during supramaximal exercise in humans. |
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Authors:
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Laurent Messonnier; Michael Kristensen; Carsten Juel; Christian Denis |
Publication Detail:
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Type: Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't Date: 2007-02-08 |
Journal Detail:
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Title: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 102 ISSN: 8750-7587 ISO Abbreviation: J. Appl. Physiol. Publication Date: 2007 May |
Date Detail:
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Created Date: 2007-05-07 Completed Date: 2007-07-13 Revised Date: 2008-02-13 |
Medline Journal Info:
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Nlm Unique ID: 8502536 Medline TA: J Appl Physiol Country: United States |
Other Details:
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Languages: eng Pagination: 1936-44 Citation Subset: IM |
Affiliation:
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Equipe Modélisation des Activités Sportives, Département STAPS, Université de Savoie, Campus Universitaire, F-73376 Le Bourget du Lac Cedex, France. laurent.messonnier@univ-savoie.fr |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Adult Alkalosis / enzymology, metabolism*, physiopathology Carbonic Anhydrases / metabolism* Cation Transport Proteins / metabolism Exercise* Female Humans Hydrogen-Ion Concentration Isoenzymes / metabolism Lactic Acid / metabolism* Linear Models Male Membrane Transport Proteins / metabolism* Monocarboxylic Acid Transporters / metabolism Muscle Contraction* Muscle Fatigue* Muscle Proteins / metabolism Muscle, Skeletal / enzymology, metabolism* Oxygen Consumption Sodium-Hydrogen Antiporter / metabolism Symporters / metabolism |
| Chemical | |
Reg. No./Substance:
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0/Cation Transport Proteins; 0/Isoenzymes; 0/Membrane Transport Proteins; 0/Monocarboxylic Acid Transporters; 0/Muscle Proteins; 0/SLC16A4 protein, human; 0/SLC9A1 protein, human; 0/Sodium-Hydrogen Antiporter; 0/Symporters; 0/monocarboxylate transport protein 1; 50-21-5/Lactic Acid; EC 4.2.1.1/Carbonic Anhydrases |
| Comments/Corrections | |
Comment In:
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J Appl Physiol. 2007 Nov;103(5):1911; author reply 1912-3
[PMID:
17965246
]
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Erratum In:
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J Appl Physiol. 2008 Jan;104(1):318 |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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