| Changes in respiratory control during and after 48 h of isocapnic and poikilocapnic hypoxia in humans. | |
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MedLine Citation:
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PMID: 9843535 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Ventilatory acclimatization to hypoxia is associated with an increase in ventilation under conditions of acute hyperoxia (VEhyperoxia) and an increase in acute hypoxic ventilatory response (AHVR). This study compares 48-h exposures to isocapnic hypoxia (protocol I) with 48-h exposures to poikilocapnic hypoxia (protocol P) in 10 subjects to assess the importance of hypocapnic alkalosis in generating the changes observed in ventilatory acclimatization to hypoxia. During both hypoxic exposures, end-tidal PO2 was maintained at 60 Torr, with end-tidal PCO2 held at the subject's prehypoxic level (protocol I) or uncontrolled (protocol P). VEhyperoxia and AHVR were assessed regularly throughout the exposures. VEhyperoxia (P < 0.001, ANOVA) and AHVR (P < 0.001) increased during the hypoxic exposures, with no significant differences between protocols I and P. The increase in VEhyperoxia was associated with an increase in slope of the ventilation-end-tidal PCO2 response (P < 0.001) with no significant change in intercept. These results suggest that changes in respiratory control early in ventilatory acclimatization to hypoxia result from the effects of hypoxia per se and not the alkalosis normally accompanying hypoxia. |
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Authors:
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J G Tansley; M Fatemian; L S Howard; M J Poulin; P A Robbins |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 85 ISSN: 8750-7587 ISO Abbreviation: J. Appl. Physiol. Publication Date: 1998 Dec |
Date Detail:
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Created Date: 1999-02-01 Completed Date: 1999-02-01 Revised Date: 2009-09-29 |
Medline Journal Info:
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Nlm Unique ID: 8502536 Medline TA: J Appl Physiol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 2125-34 Citation Subset: IM |
Affiliation:
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University Laboratory of Physiology, University of Oxford, Oxford OX1 3PT, United Kingdom. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Acclimatization
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physiology Acid-Base Equilibrium Adolescent Adult Alkalosis / blood, physiopathology Anoxia / blood, physiopathology* Carbon Dioxide / blood* Female Humans Hydrogen-Ion Concentration Hyperventilation / physiopathology Male Respiratory Mechanics / physiology* Time Factors |
| Grant Support | |
ID/Acronym/Agency:
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//Wellcome Trust |
| Chemical | |
Reg. No./Substance:
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124-38-9/Carbon Dioxide |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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