Increase of sympathetic discharge to skeletal muscle but not to skin during mild lower body negative pressure in humans.

Détails

ID Serval
serval:BIB_1EF3B28B9525
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Increase of sympathetic discharge to skeletal muscle but not to skin during mild lower body negative pressure in humans.
Périodique
Journal of Physiology
Auteur(s)
Vissing S.F., Scherrer U., Victor R.G.
ISSN
0022-3751
Statut éditorial
Publié
Date de publication
11/1994
Peer-reviewed
Oui
Volume
481
Numéro
1
Pages
233-241
Langue
anglais
Notes
Publication types: Journal Article ;
Résumé
1. Haemodynamic studies in humans have concluded that the cutaneous circulation is regulated by cardiopulmonary baroreceptors. In contrast, neurophysiological studies have indicated that skin sympathetic outflow, unlike muscle sympathetic outflow, is unaffected by perturbations in baroreceptor activity. 2. Thus, in an attempt to resolve this discrepancy, both muscle and skin sympathetic nerve activity was recorded during unloading of mainly cardiopulmonary afferents with non-hypotensive lower body negative pressure (LBNP) performed in both normothermic and hyperthermic conditions. The function of the sympathetic activity was studied by estimations of skin blood flow (laser Doppler velocimetry), of calf blood flow (plethysmography) and of sudomotor activity (electrodermal responses). 3. A level of LBNP that caused robust increases in sympathetic outflow and vascular resistance in the skeletal muscle of the lower leg had no effect on sympathetic activity and vascular resistance in the skin of the same region in the same subjects. Both at normothermia and during hyperthermia LBNP decreased electrodermal activity. Experiments performed during sham LBNP and with skin temperature kept constant suggest that the electrodermal response was due to a decrease in skin temperature produced by the LBNP. 4. In conclusion, these findings challenge the concept that the cutaneous circulation participates importantly in the peripheral circulatory adjustments to unloading of cardiopulmonary afferents during orthostatic stress in humans. During non-hypotensive LBNP, the skeletal muscle bed accounts for all of the reflex vasoconstriction in the calf.
Mots-clé
Adult, Humans, Laser-Doppler Flowmetry, Lower Body Negative Pressure, Male, Middle Aged, Muscle, Skeletal/innervation, Skin/innervation, Skin Temperature/physiology, Sympathetic Nervous System/physiology
Pubmed
Web of science
Création de la notice
25/01/2008 14:04
Dernière modification de la notice
20/08/2019 12:54
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