| The ventilatory response to CO2 of the peripheral and central chemoreflex loop before and after sustained hypoxia in man. | |
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MedLine Citation:
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PMID: 1293293 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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1. The ventilatory response to sustained hypoxia is characterized by a fast increase due to the peripheral chemoreceptors followed by a slow decline. The mechanism of this decline is unknown. 2. To investigate the characteristics of the ventilatory response to sustained hypoxia ten healthy subjects were exposed to two consecutive periods of isocapnic hypoxia (arterial saturation 78%) separated by a 5 min exposure to isocapnic normoxia. 3. The acute hypoxic response to the second exposure to hypoxia (mean increase in ventilation +/- S.E.M., 7.2 +/- 0.8 l min-1) was significantly depressed (P = 0.04) compared to the first one (9.5 +/- 1.3 l min-1). 4. To investigate whether this depression was due to central or peripheral effects or both we measured, in the same ten subjects, the normoxic ventilatory response to CO2 before and after a period of 25 min of hypoxia using the technique of dynamic end-tidal forcing. 5. Each response was separated into a fast peripheral and slow central component characterized by a CO2 sensitivity, time constant, time delay and an off-set. 6. A total of thirty-six prehypoxic and thirty posthypoxic responses were analysed. The ventilatory CO2 sensitivities of the peripheral and central chemoreflex loops and the overall off-set (apnoeic threshold) after 25 min of hypoxia were somewhat larger than their prehypoxic values, but this effect was not significant. 7. We argue that the hypoxic ventilatory decline in man is due to a change in the off-set of the peripheral chemoreflex loop. |
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Authors:
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A Berkenbosch; A Dahan; J DeGoede; I C Olievier |
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Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: The Journal of physiology Volume: 456 ISSN: 0022-3751 ISO Abbreviation: J. Physiol. (Lond.) Publication Date: 1992 Oct |
Date Detail:
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Created Date: 1993-04-05 Completed Date: 1993-04-05 Revised Date: 2010-09-07 |
Medline Journal Info:
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Nlm Unique ID: 0266262 Medline TA: J Physiol Country: ENGLAND |
Other Details:
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Languages: eng Pagination: 71-83 Citation Subset: IM |
Affiliation:
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Department of Physiology, University of Leiden, The Netherlands. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adult Carbon Dioxide / physiology* Chemoreceptor Cells / physiology* Female Humans Male Oxygen / blood, physiology* Respiration / physiology* Sensory Thresholds / physiology Time Factors |
| Chemical | |
Reg. No./Substance:
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124-38-9/Carbon Dioxide; 7782-44-7/Oxygen |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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