Document Detail


Arterial pressure in humans during weightlessness induced by parabolic flights.
MedLine Citation:
PMID:  10484559     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Results from our laboratory have indicated that, compared with those of the 1-G supine (Sup) position, left atrial diameter (LAD) and transmural central venous pressure increase in humans during weightlessness (0 G) induced by parabolic flights (R. Videbaek and P. Norsk. J. Appl. Physiol. 83: 1862-1866, 1997). Therefore, because cardiopulmonary low-pressure receptors are stimulated during 0 G, the hypothesis was tested that mean arterial pressure (MAP) in humans decreases during 0 G to values below those of the 1-G Sup condition. When the subjects were Sup, 0 G induced a decrease in MAP from 93 +/- 4 to 88 +/- 4 mmHg (P < 0.001), and LAD increased from 30 +/- 1 to 33 +/- 1 mm (P < 0.001). In the seated position, MAP also decreased from 93 +/- 6 to 87 +/- 5 mmHg (P < 0.01) and LAD increased from 28 +/- 1 to 32 +/- 1 mm (P < 0.001). During 1-G conditions with subjects in the horizontal left lateral position, LAD increased compared with that of Sup (P < 0.001) with no further effects of 0 G. In conclusion, MAP decreases during short-term weightlessness to below that of 1-G Sup simultaneously with an increase in LAD. Therefore, distension of the heart and associated central vessels during 0 G might induce the hypotensive effects through peripheral vasodilatation. Furthermore, the left lateral position in humans could constitute a simulation model of weightlessness.
Authors:
B Pump; R Videbaek; A Gabrielsen; P Norsk
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Publication Detail:
Type:  Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  87     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1999 Sep 
Date Detail:
Created Date:  1999-10-14     Completed Date:  1999-10-14     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  928-32     Citation Subset:  IM; S    
Affiliation:
Danish Aerospace Medical Centre of Research and Cardiovascular Laboratory, National University Hospital, DK-2200 Copenhagen, Denmark. damec@inet.uni2.dk
Space Flight Mission:
Flight Experiment; Parabolic Flight; manned; short duration
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MeSH Terms
Descriptor/Qualifier:
Adult
Atrial Function, Left / physiology
Blood Pressure / physiology*
Central Venous Pressure / physiology
Female
Heart Rate / physiology
Humans
Male
Middle Aged
Pressoreceptors / physiology
Supine Position / physiology
Vasodilation / physiology
Weightlessness / adverse effects*
Weightlessness Simulation / methods*

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


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