| Regional vascular responses to prolonged lower body negative pressure in normal subjects. | |
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MedLine Citation:
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PMID: 2750938 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The purpose of this study was to determine the effects of sustained unloading of baroreceptors in humans. The regional hemodynamic responses to lower body negative pressure (LBNP) were determined in 20 normal subjects. LBNP at -10 mmHg for 1 h decreased central venous pressure (CVP) without affecting blood pressure or heart rate, suggesting that only cardiopulmonary baroreceptors were unloaded. Forearm blood flow (FBF) and splanchnic blood flow (SBF) both decreased. Renal blood flow (RBF) did not change, but glomerular filtration rate (GFR) increased. Plasma renin activity rose slightly, whereas plasma norepinephrine levels did not change. Peak LBNP (either -20 or -40 mmHg for 1 h) caused a further decline in CVP and narrowed pulse pressure, thus unloading both arterial and cardiopulmonary baroreceptors. FBF returned to base-line values and SBF decreased further. RBF fell and the GFR remained increased. Plasma renin activity increased further, and plasma norepinephrine level rose. Thus the forearm and splanchnic circulations are sensitive to sustained unloading of cardiopulmonary baroreceptors; renal vasoconstriction occurs with additional unloading of arterial baroreceptors. Renin-angiotensin system activation during LBNP may be pertinent to the preservation of glomerular filtration. |
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Authors:
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A T Hirsch; D J Levenson; S S Cutler; V J Dzau; M A Creager |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: The American journal of physiology Volume: 257 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1989 Jul |
Date Detail:
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Created Date: 1989-08-16 Completed Date: 1989-08-16 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0370511 Medline TA: Am J Physiol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: H219-25 Citation Subset: IM; S |
Affiliation:
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Division of Vascular Medicine and Atherosclerosis, Brigham and Women's Hospital, Boston, Massachusetts 02115. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adult Decompression* Extremities / blood supply Female Hemodynamics* Hormones / blood Humans Kidney / physiology Lower Body Negative Pressure* Male Pressoreceptors / physiology* Regional Blood Flow Renal Circulation Splanchnic Circulation |
| Grant Support | |
ID/Acronym/Agency:
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5-T32-HL-07609/HL/NHLBI NIH HHS; HL-36348/HL/NHLBI NIH HHS; HL-36568/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Hormones |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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