Document Detail


The ventilatory response to CO2 of the peripheral and central chemoreflex loop before and after sustained hypoxia in man.
MedLine Citation:
PMID:  1293293     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
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.
Authors:
A Berkenbosch; A Dahan; J DeGoede; I C Olievier
Related Documents :
12834883 - Nitric oxide in the rostral ventrolateral medulla modulates hyperpnea but not anapyrexi...
2515273 - Effects of peripheral and central chemoreflex activation on the isopnoeic rating of bre...
23416403 - Cardiac output, o(2) delivery and [formula: see text] kinetics during step exercise in ...
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Journal of physiology     Volume:  456     ISSN:  0022-3751     ISO Abbreviation:  J. Physiol. (Lond.)     Publication Date:  1992 Oct 
Date Detail:
Created Date:  1993-04-05     Completed Date:  1993-04-05     Revised Date:  2010-09-07    
Medline Journal Info:
Nlm Unique ID:  0266262     Medline TA:  J Physiol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  71-83     Citation Subset:  IM    
Affiliation:
Department of Physiology, University of Leiden, The Netherlands.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adult
Carbon Dioxide / physiology*
Chemoreceptor Cells / physiology*
Female
Humans
Male
Oxygen / blood,  physiology*
Respiration / physiology*
Sensory Thresholds / physiology
Time Factors
Chemical
Reg. No./Substance:
124-38-9/Carbon Dioxide; 7782-44-7/Oxygen
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Role of basal release of nitric oxide on coronary flow and mechanical performance of the isolated ra...
Next Document:  Phonological transformations in conduction aphasia.