Document Detail


Plasma glucose kinetics during exercise in subjects with high and low lactate thresholds.
MedLine Citation:
PMID:  1474063     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The purpose of this study was to test the hypothesis that the rate of plasma glucose oxidation during exercise is inversely related to muscle respiratory capacity. To this end, 14 subjects were studied: in 7 of these subjects, the blood lactate threshold (LT) occurred at a relatively high intensity [i.e., at 65 +/- 2% of peak cycle ergometer oxygen uptake (VO2 peak)], whereas in the other 7 subjects, LT occurred at a relatively low intensity (i.e., at 45 +/- 2% of VO2 peak). VO2peak did not differ between the two groups, but citrate synthase activity in the vastus lateralis muscle was 53% higher (P < 0.05) in the high LT group. A primed continuous infusion of [U-13C]glucose was used to quantify rates of glucose appearance (Ra), disappearance (Rd), and oxidation (R(ox)) during 90 min of exercise at 55% VO2peak. Although both absolute and relative rates of oxygen uptake during exercise were similar in the two groups, mean Ra and Rd were 17% lower (P < 0.001) in the high LT group, and mean R(ox) was 25% lower (21.0 +/- 2.6 vs. 27.9 +/- 2.6 mumol.min-1.kg-1; P < 0.001). The percentage of total energy derived from glucose oxidation was inversely related to muscle citrate synthase activity (r = -0.85; P < 0.01). These data support the concept that skeletal muscle respiratory capacity has a major role in determining the metabolic response to submaximal exercise.
Authors:
A R Coggan; W M Kohrt; R J Spina; J P Kirwan; D M Bier; J O Holloszy
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  73     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1992 Nov 
Date Detail:
Created Date:  1993-02-01     Completed Date:  1993-02-01     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1873-80     Citation Subset:  IM    
Affiliation:
Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110.
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MeSH Terms
Descriptor/Qualifier:
Adult
Anaerobic Threshold / physiology*
Blood Glucose / metabolism*
Breath Tests
Citrate (si)-Synthase / metabolism
Exercise / physiology*
Fatty Acids, Nonesterified / blood
Female
Heart Rate / physiology
Humans
Insulin / blood
Kinetics
Lactates / blood,  metabolism*
Male
Mitochondria, Muscle / metabolism
Oxidation-Reduction
Oxygen Consumption / physiology
Physical Fitness / physiology
Grant Support
ID/Acronym/Agency:
AM-20579/AM/NIADDK NIH HHS; RR-00036/RR/NCRR NIH HHS; RR-00954/RR/NCRR NIH HHS
Chemical
Reg. No./Substance:
0/Blood Glucose; 0/Fatty Acids, Nonesterified; 0/Lactates; 11061-68-0/Insulin; EC 2.3.3.1/Citrate (si)-Synthase
Comments/Corrections
Comment In:
J Appl Physiol. 1993 May;74(5):2613-4   [PMID:  8380022 ]

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


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