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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1994-12-12
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pubmed:abstractText |
Simultaneous measurements of phosphocreatine (PCr) and oxyhemoglobin (HbO2) saturation were made during recovery from exercise in calf muscles of five male subjects. PCr was measured using magnetic resonance spectroscopy in a 2.0-T 78-cm-bore magnet with a 9-cm-diam surface coil. Relative HbO2 saturation was measured as the difference in absorption of 750- and 850-nm light with use of near-infrared spectroscopy. The light source and detectors were 3 cm apart. Exercise consisted of isokinetic plantar flexion in a supine position. Two 5-min submaximal protocols were performed with PCr depletion to 60% of resting values and with pH values of > 7.0. Then two 1-min protocols of rapid plantar flexion were performed to deplete PCr values to 5-20% of resting values with pH values of < 6.8. Areas of PCr peaks (every 8 s) and HbO2 saturation (every 1 s) were fit to a monoexponential function, and a time constant was calculated. The PCr time constant was larger after maximal exercise (68.3 +/- 10.5 s) than after submaximal exercise (36.0 +/- 6.5 s), which is consistent with the effects of low pH on PCr recovery. HbO2 resaturation approximated submaximal PCr recovery and was not different between maximal (29.4 +/- 5.5 s) and submaximal (27.6 +/- 6.0 s) exercise. We conclude that magnetic resonance spectroscopy measurements of PCr recovery and near-infrared spectroscopy measurements of recovery of HbO2 saturation provide similar information as long as muscle pH remains near 7.0.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Jul
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pubmed:issn |
8750-7587
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
77
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
5-10
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pubmed:dateRevised |
2004-11-17
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pubmed:meshHeading |
pubmed-meshheading:7961273-Adult,
pubmed-meshheading:7961273-Exercise,
pubmed-meshheading:7961273-Hemoglobins,
pubmed-meshheading:7961273-Humans,
pubmed-meshheading:7961273-Hydrogen-Ion Concentration,
pubmed-meshheading:7961273-Kinetics,
pubmed-meshheading:7961273-Leg,
pubmed-meshheading:7961273-Magnetic Resonance Spectroscopy,
pubmed-meshheading:7961273-Male,
pubmed-meshheading:7961273-Muscle, Skeletal,
pubmed-meshheading:7961273-Oxygen,
pubmed-meshheading:7961273-Oxygen Consumption,
pubmed-meshheading:7961273-Phosphocreatine,
pubmed-meshheading:7961273-Spectrophotometry, Infrared
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pubmed:year |
1994
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pubmed:articleTitle |
Simultaneous in vivo measurements of HbO2 saturation and PCr kinetics after exercise in normal humans.
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pubmed:affiliation |
Department of Medicine, Medical College of Pennsylvania, Philadelphia 19131.
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pubmed:publicationType |
Journal Article,
Clinical Trial
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