Document Detail

Influence of active muscle mass on glucose homeostasis during exercise in humans.
MedLine Citation:
PMID:  1938728     Owner:  NLM     Status:  MEDLINE    
To study the effect of increasing amounts of exercising muscle mass on the relationship between glucose mobilization and peripheral glucose uptake, seven young men (23-28 yr) bicycled for 70 min at a work load of 55-60% VO2max. From minute 30 to 50, arm cranking was added and total work load increased to 82 +/- 4% VO2max. During leg exercise, hepatic glucose production (Ra) increased in parallel with peripheral glucose uptake (Rd) and euglycemia was maintained. During arm + leg exercise, Ra increased more than Rd and accordingly plasma glucose increased from 5.11 +/- 0.22 to 8.00 +/- 0.66 mmol/l (P less than 0.05). Plasma catecholamines increased three- to four-fold more during arm + leg exercise than during leg exercise. Leg glucose uptake increased with time regardless of arm cranking. Net leg lactate release during leg exercise was reverted to a net leg lactate uptake during arm + leg exercise. The rate of glycogen breakdown in exercising leg muscle was not altered by addition of arm cranking. In conclusion, when large amounts of muscle mass are active, plasma catecholamines increase sharply and mobilization of glucose exceeds peripheral glucose uptake. This indicates that mechanisms other than feedback regulation to maintain euglycemia are involved in hormonal and substrate mobilization during intense exercise in humans.
M Kjaer; B Kiens; M Hargreaves; E A Richter
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  71     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1991 Aug 
Date Detail:
Created Date:  1991-12-11     Completed Date:  1991-12-11     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  552-7     Citation Subset:  IM; S    
August Krogh Institute, University of Copenhagen, Denmark.
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MeSH Terms
Arm / blood supply,  physiology
Blood Glucose / metabolism
Catecholamines / blood
Exercise / physiology*
Fatty Acids, Nonesterified / blood
Glucose / metabolism*
Glycerol / blood
Homeostasis / physiology*
Hormones / metabolism
Insulin / blood
Leg / blood supply
Liver / metabolism
Muscles / anatomy & histology,  physiology*
Organ Size / physiology
Oxygen Consumption / physiology
Regional Blood Flow / physiology
Reg. No./Substance:
0/Blood Glucose; 0/Catecholamines; 0/Fatty Acids, Nonesterified; 0/Hormones; 0/Insulin; 50-99-7/Glucose; 56-81-5/Glycerol

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

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