Augmented sympathetic activation during short-term hypoxia and high-altitude exposure in subjects susceptible to high-altitude pulmonary edema

Details

Serval ID
serval:BIB_94805C1D1F43
Type
Article: article from journal or magazin.
Collection
Publications
Title
Augmented sympathetic activation during short-term hypoxia and high-altitude exposure in subjects susceptible to high-altitude pulmonary edema
Journal
Circulation
Author(s)
Duplain  H., Vollenweider  L., Delabays  A., Nicod  P., Bartsch  P., Scherrer  U.
ISSN
0009-7322 (Print)
Publication state
Published
Issued date
04/1999
Volume
99
Number
13
Pages
1713-8
Notes
Clinical Trial
Controlled Clinical Trial
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Apr 6
Abstract
BACKGROUND: Pulmonary hypertension is a hallmark of high-altitude pulmonary edema and may contribute to its pathogenesis. Cardiovascular adjustments to hypoxia are mediated, at least in part, by the sympathetic nervous system, and sympathetic activation promotes pulmonary vasoconstriction and alveolar fluid flooding in experimental animals. METHODS AND RESULTS: We measured sympathetic nerve activity (using intraneural microelectrodes) in 8 mountaineers susceptible to high-altitude pulmonary edema and 7 mountaineers resistant to this condition during short-term hypoxic breathing at low altitude and at rest at a high-altitude laboratory (4559 m). We also measured systolic pulmonary artery pressure to examine the relationship between sympathetic activation and pulmonary vasoconstriction. In subjects prone to pulmonary edema, short-term hypoxic breathing at low altitude evoked comparable hypoxemia but a 2- to 3-times-larger increase in the rate of the sympathetic nerve discharge than in subjects resistant to edema (P<0.001). At high altitude, in subjects prone to edema, the increase in the mean+/-SE sympathetic firing rate was >2 times larger than in those resistant to edema (36+/-7 versus 15+/-4 bursts per minute, P<0.001) and preceded the development of lung edema. We observed a direct relationship between sympathetic nerve activity and pulmonary artery pressure measured at low and high altitude in the 2 groups (r=0.83, P<0.0001). CONCLUSIONS: With the use of direct measurements of postganglionic sympathetic nerve discharge, these data provide the first evidence for an exaggerated sympathetic activation in subjects prone to high-altitude pulmonary edema both during short-term hypoxic breathing at low altitude and during actual high-altitude exposure. Sympathetic overactivation may contribute to high-altitude pulmonary edema.
Keywords
Adult *Altitude Anoxia/*physiopathology Disease Susceptibility Female Humans Male Middle Aged Pulmonary Edema/*physiopathology Sympathetic Fibers, Postganglionic/physiopathology Sympathetic Nervous System/*physiopathology Time Factors
Pubmed
Web of science
Create date
25/01/2008 14:44
Last modification date
20/08/2019 15:57
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