Document Detail


Cerebrovascular responses to altitude.
MedLine Citation:
PMID:  17544954     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The regulation of cerebral blood flow (CBF) is a complex process that is altered significantly with altitude exposure. Acute exposure produces a marked increase in CBF, in proportion to the severity of the hypoxia and mitigated by hyperventilation-induced hypocapnia when CO(2) is uncontrolled. A number of mediators contribute to the hypoxia-induced cerebral vasodilation, including adenosine, potassium channels, substance P, prostaglandins, and NO. Upon acclimatization to altitude, CBF returns towards normal sea-level values in subsequent days and weeks, mediated by a progressive increase in PO2, first through hyperventilation followed by erythropoiesis. With long-term altitude exposure, a number of mechanisms play a role in regulating CBF, including acid-base balance, hematological modifications, and angiogenesis. Finally, several cerebrovascular disorders are associated with altitude exposure. Existing gaps in our knowledge of CBF and altitude, and areas of future investigation include effects of longer exposures, intermittent hypoxia, and gender differences in the CBF responses to altitude.
Authors:
Julien V Brugniaux; Alastair N H Hodges; Patrick J Hanly; Marc J Poulin
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Review     Date:  2007-05-01
Journal Detail:
Title:  Respiratory physiology & neurobiology     Volume:  158     ISSN:  1569-9048     ISO Abbreviation:  Respir Physiol Neurobiol     Publication Date:  2007 Sep 
Date Detail:
Created Date:  2007-09-24     Completed Date:  2008-01-03     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101140022     Medline TA:  Respir Physiol Neurobiol     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  212-23     Citation Subset:  IM    
Affiliation:
Department of Physiology & Biophysics, University of Calgary, Calgary, Alberta T2N 4N1, Canada.
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MeSH Terms
Descriptor/Qualifier:
Acclimatization / physiology*
Altitude*
Altitude Sickness / blood
Animals
Anoxia / blood
Atmospheric Pressure
Cerebrovascular Circulation / physiology*
Humans
Oxygen / blood*
Pulmonary Gas Exchange / physiology
Vasodilation / physiology*
Chemical
Reg. No./Substance:
7782-44-7/Oxygen

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


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