| Time course of aerobic recovery after contraction of rabbit papillary muscle. | |
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MedLine Citation:
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PMID: 3618807 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The time course of oxygen uptake after isometric twitch contractions of isolated rabbit papillary muscles was determined at 20 degrees C by continuous polarographic measurement of the partial pressure of oxygen in a 219-microliters glass chamber in which the fluid circulated rapidly. The response time of the oxygen-measuring system was characterized by a delay of 1.1 s and a time constant of 2.1 s after that delay. Depending on the stimulation frequency (0.125-1.0 Hz) the total amount of oxygen uptake for 120 twitches varied from 5.3 to 32.7 nmol/mg dry wt, and the steady-state oxygen consumption rate varied from 0.4 to 8.5 nmol X min-1 X mg dry wt-1. On the basis of a diffusion model we eliminated the effect of oxygen storage on the measured time course of oxygen consumption to determine the mitochondrial kinetics. We found a time constant of an average 19-22 s of mitochondrial off kinetics. By use of this time constant for the change in oxygen consumption rate after contraction, it can be estimated that 9-10% of the oxygen required to restore ATP levels is already taken up by the mitochondria during the twitch. |
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Authors:
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F Mast; G Elzinga |
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Publication Detail:
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Type: In Vitro; Journal Article |
Journal Detail:
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Title: The American journal of physiology Volume: 253 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1987 Aug |
Date Detail:
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Created Date: 1987-09-17 Completed Date: 1987-09-17 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0370511 Medline TA: Am J Physiol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: H325-32 Citation Subset: IM |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Mitochondria, Heart / metabolism Myocardial Contraction* Oxygen Consumption* Papillary Muscles / metabolism, physiology* Rabbits Rest Time Factors |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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