Document Detail

Delayed reoxygenation after maximal isometric handgrip exercise in high oxidative capacity muscle.
MedLine Citation:
PMID:  12627303     Owner:  NLM     Status:  MEDLINE    
We hypothesized that after maximal short-term isometric exercise, when O(2) demand is still high and O(2) supply is not fully activated, higher oxidative capacity muscle may exhibit slower muscle reoxygenation after the exercise than low oxidative capacity muscle. Seven healthy male subjects performed a maximal voluntary isometric handgrip exercise for 10 s. The reoxygenation rate after the exercise (Reoxy-rate) in the finger flexor muscle was determined by near infrared continuous wave spectroscopy (NIRcws) while phosphocreatine (PCr) was measured simultaneously by (31)P magnetic resonance spectroscopy. Muscle oxygen consumption (muscle VO(2)) and muscle oxidative capacity were evaluated using the rate of PCr resynthesis post-exercise. The forearm blood flow (FBF) index at the end of exercise was measured using NIRcws. There was a significant positive correlation between the Reoxy-rate, which ranged between 0.53% s(-1) and 12.47% s(-1), and the time constant for PCr resynthesis, which ranged between 17.8 s and 38.3 s (r(2)=0.939, P<0.001). At the end of the exercise, muscle VO(2) exceeded the resting level by approximately 25-fold, while the FBF index exceeded the resting level by only 3-fold on average. The Reoxy-rate closely correlated with muscle VO(2) (r(2)=0.727, P<0.05), but not with the FBF index. Also, the estimated O(2) balance (muscle VO(2) index/FBF index) was negatively correlated with the Reoxy-rate (r(2)=0.820, P<0.001). These results support our hypothesis that higher oxidative capacity muscle shows slower muscle reoxygenation after maximal short-term isometric exercise because the Reoxy-rate after this type of exercise may be influenced more by muscle VO(2) than by O(2) supply.
Ryotaro Kime; Takafumi Hamaoka; Takayuki Sako; Motohide Murakami; Toshiyuki Homma; Toshihito Katsumura; Britton Chance
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Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article; Validation Studies     Date:  2002-12-24
Journal Detail:
Title:  European journal of applied physiology     Volume:  89     ISSN:  1439-6319     ISO Abbreviation:  Eur. J. Appl. Physiol.     Publication Date:  2003 Mar 
Date Detail:
Created Date:  2003-03-10     Completed Date:  2003-11-20     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  100954790     Medline TA:  Eur J Appl Physiol     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  34-41     Citation Subset:  IM    
Department of Biochemistry and Biophysics, 250 Anatomy-Chemistry Building, University of Pennsylvania, 37th and Hamilton Walk, Philadelphia, PA 19104-6059, USA.
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MeSH Terms
Adaptation, Physiological / physiology*
Exercise / physiology*
Fingers / physiology
Hand Strength
Homeostasis / physiology
Isometric Contraction / physiology*
Magnetic Resonance Imaging
Muscle, Skeletal / physiology*
Myoglobin / metabolism
Oxygen / metabolism*
Oxygen Consumption / physiology*
Oxyhemoglobins / metabolism
Phosphocreatine / metabolism*
Physical Exertion / physiology
Spectroscopy, Near-Infrared
Reg. No./Substance:
0/Myoglobin; 0/Oxyhemoglobins; 0/oxymyoglobin; 67-07-2/Phosphocreatine; 7782-44-7/Oxygen

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