Linked Life Data

16235431

Source:http://linkedlifedata.com/resource/pubmed/id/16235431

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2005-10-19
pubmed:abstractText
We tested the hypothesis that vasoconstriction in response to LBNP or head up tilt would be reflected in a reduction in splanchnic (portal vein) blood flow (PVF) and increases in forearm and total peripheral vascular resistance (TPR). Changes in vascular resistance indicators were obtained from measurement of PVF from portal vein cross-sectional area and blood velocity by Doppler ultrasound, from forearm vascular resistance (FVR, by Doppler) and total peripheral resistance (TPR, by impedance cardiography). 21 subjects were tested during LBNP (0, -10, -20 and -30 mmHg) and 9 subjects during tilt (0, 45 and 70 degrees). During progressive LBNP, PVF decreased approximately linearly with LBNP (-30, -48 and -64% at -10, -20 and -30 mmHg) and with tilt angle (-39 and -58% at 45 and 70 degrees). The increase in FVR approximately mirrored these changes during LBNP (20.1, 44.7 and 55.3%) and tilt (45.6 and 63.6%). However, the changes in TPR during LBNP (12.0, 16.9 and 26.4%) and tilt (25.2 and 29.2%) were markedly less. This observation of different percent changes in forearm versus total peripheral resistance might reflect true physiological differences in the forearm (and splanchnic) circulations compared with the whole body, or the data might suggest that impedance cardiography did not provide a reliable indicator of cardiac output and therefore TPR under these conditions. The primary observation in this study was that Doppler ultrasound measurement of portal vein blood flow provided a non-invasive estimate of splanchnic vascular resistance during postural or LBNP challenge and that using the reduction in portal vein flow as an index of increased vasoconstriction paralleled the change in forearm vascular resistance.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
S
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1077-9248
pubmed:author
pubmed:issnType
Print
pubmed:volume
11
pubmed:owner
NASA
pubmed:authorsComplete
Y
pubmed:pagination
P95-6
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Splanchnic and peripheral vascular resistance during lower body negative pressure (LBNP) and tilt.
pubmed:affiliation
Cardiorespiratory & Vascular Dynamics Lab, Univ. Waterloo, Waterloo, Ontario, Canada. hughson@uwaterloo.ca
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't