Document Detail


Subcutaneous and skeletal muscle vascular responses in human limbs to lower body negative pressure.
MedLine Citation:
PMID:  1585809     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Cardiopulmonary baroreceptor unloading in humans comparably increases sympathetic discharge to skeletal muscle in the forearm and calf, but blood flow studies have disclosed differential rather than uniform vasomotor responses in the extremities. The aim of the present study was to address the issue of differential effects of orthostatic stress on forearm and calf vascular adjustment and to extend previous studies by determining changes in vascular responses separately in various vascular beds of the limbs. The local [133Xenon] washout method was used for recording blood flow rates in subcutaneous tissue and skeletal muscle. Simultaneous recordings from the forearm and calf were performed in 11 healthy young males during lower body negative pressure at -10 mmHg. Heart rate, arterial mean and pulse pressures did not change during lower body negative pressure. In the forearm blood flow rates decreased significantly, in subcutaneous tissue by 16 +/- 2% (mean +/- SEM) and in skeletal muscle by 16 +/- 1%. In the calf lower body negative pressure induced a significant decrease in blood flow rates of 17 +/- 3% in subcutaneous tissue and of 30 +/- 2% in skeletal muscle. This vasoconstriction in calf skeletal muscle was consistently disclosed in both legs and was about the same magnitude in each calf when studied with the one leg exposed to lower body negative pressure and the other outside the lower body negative pressure chamber. These findings suggest that during unloading of cardiopulmonary afferents, reflex sympathetic activation as an important autonomic adjustment to orthostatic stress is accompanied by uniform vasoconstriction in subcutaneous and skeletal muscle vascular beds of human limbs.
Authors:
T N Jacobsen; H V Nielsen; E Kassis; O Amtorp
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Acta physiologica Scandinavica     Volume:  144     ISSN:  0001-6772     ISO Abbreviation:  Acta Physiol. Scand.     Publication Date:  1992 Mar 
Date Detail:
Created Date:  1992-06-12     Completed Date:  1992-06-12     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370362     Medline TA:  Acta Physiol Scand     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  247-52     Citation Subset:  IM; S    
Affiliation:
Department of Cardiology, Gentofte Hospital, University of Copenhagen, Denmark.
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MeSH Terms
Descriptor/Qualifier:
Adult
Afferent Pathways / physiology
Connective Tissue / blood supply,  innervation
Extremities / blood supply*
Humans
Lower Body Negative Pressure*
Male
Muscles / blood supply,  innervation
Regional Blood Flow / physiology
Vascular Resistance / physiology

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


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