Source:http://linkedlifedata.com/resource/pubmed/id/11709433
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
6
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pubmed:dateCreated |
2001-11-15
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pubmed:abstractText |
We hypothesized that blockade of alpha(1)-adrenergic receptors would prevent the rise in peripheral vascular resistance that normally occurs during acclimatization. Sixteen eumenorrheic women were studied at sea level (SL) and at 4,300 m (days 3 and 10). Volunteers were randomly assigned to take the selective alpha(1)-blocker prazosin or placebo. Venous compliance, forearm vascular resistance, and blood flow were measured using plethysmography. Venous compliance fell by day 3 in all subjects (1.39 +/- 0.30 vs. 1.62 +/- 0.43 ml. Delta 30 mmHg(-1) x 100 ml tissue(-1) x min(-1) at SL, means +/- SD). Altitude interacted with prazosin treatment (P < 0.0001) such that compliance returned to SL values by day 10 in the prazosin-treated group (1.68 +/- 0.19) but not in the placebo-treated group (1.20 +/- 0.10, P < 0.05). By day 3 at 4,300 m, all women had significant falls in resistance (35.2 +/- 13.2 vs. 54.5 +/- 16.1 mmHg x ml(-1) x min(-1) at SL) and rises in blood flow (2.5 +/- 1.0 vs. 1.6 +/- 0.5 ml. 100 ml tissue(-1) x min(-1) at SL). By day 10, resistance and flow returned toward SL, but this return was less in the prazosin-treated group (resistance: 39.8 +/- 4.6 mmHg x ml(-1) x min(-1) with prazosin vs. 58.5 +/- 9.8 mmHg x ml(-1) x min(-1) with placebo; flow: 1.9 +/- 0.7 ml. 100 ml tissue(-1) x min(-1) with prazosin vs. 2.3 +/- 0.3 ml x 100 ml tissue(-1) x min(-1) with placebo, P < 0.05). Lower resistance related to higher circulating epinephrine in both groups (r = -0.50, P < 0.0001). Higher circulating norepinephrine related to lower venous compliance in the placebo-treated group (r = -0.42, P < 0.05). We conclude that alpha(1)-adrenergic stimulation modulates peripheral vascular changes during acclimatization.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
0363-6135
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
281
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
H2636-44
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:11709433-Acclimatization,
pubmed-meshheading:11709433-Adrenergic alpha-Antagonists,
pubmed-meshheading:11709433-Adult,
pubmed-meshheading:11709433-Altitude,
pubmed-meshheading:11709433-Blood Pressure,
pubmed-meshheading:11709433-Epinephrine,
pubmed-meshheading:11709433-Female,
pubmed-meshheading:11709433-Forearm,
pubmed-meshheading:11709433-Humans,
pubmed-meshheading:11709433-Norepinephrine,
pubmed-meshheading:11709433-Plethysmography,
pubmed-meshheading:11709433-Prazosin,
pubmed-meshheading:11709433-Regional Blood Flow,
pubmed-meshheading:11709433-Vascular Resistance,
pubmed-meshheading:11709433-Veins
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pubmed:year |
2001
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pubmed:articleTitle |
Women at altitude: forearm hemodynamics during acclimatization to 4,300 m with alpha(1)-adrenergic blockade.
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pubmed:affiliation |
Women's Health Research Center, University of Colorado Health Sciences Center, Denver, 80262, USA. Stacy.Zamudio@uchsc.edu
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pubmed:publicationType |
Journal Article,
Clinical Trial,
Research Support, U.S. Gov't, Non-P.H.S.,
Randomized Controlled Trial
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