Arterial baroreflex buffering of sympathetic activation during exercise-induced elevations in arterial pressure

Détails

ID Serval
serval:BIB_06C53905B7F8
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Arterial baroreflex buffering of sympathetic activation during exercise-induced elevations in arterial pressure
Périodique
Journal of Clinical Investigation
Auteur(s)
Scherrer  U., Pryor  S. L., Bertocci  L. A., Victor  R. G.
ISSN
0021-9738 (Print)
Statut éditorial
Publié
Date de publication
12/1990
Volume
86
Numéro
6
Pages
1855-61
Notes
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S. --- Old month value: Dec
Résumé
Static muscle contraction activates metabolically sensitive muscle afferents that reflexively increase sympathetic nerve activity and arterial pressure. To determine if this contraction-induced reflex is modulated by the sinoaortic baroreflex, we performed microelectrode recordings of sympathetic nerve activity to resting leg muscle during static handgrip in humans while attempting to clamp the level of baroreflex stimulation by controlling the exercise-induced rise in blood pressure with pharmacologic agents. The principal new finding is that partial pharmacologic suppression of the rise in blood pressure during static handgrip (nitroprusside infusion) augmented the exercise-induced increases in heart rate and sympathetic activity by greater than 300%. Pharmacologic accentuation of the exercise-induced rise in blood pressure (phenylephrine infusion) attenuated these reflex increases by greater than 50%. In contrast, these pharmacologic manipulations in arterial pressure had little or no effect on: (a) forearm muscle cell pH, an index of the metabolic stimulus to skeletal muscle afferents; or (b) central venous pressure, an index of the mechanical stimulus to cardiopulmonary afferents. We conclude that in humans the sinoaortic baroreflex is much more effective than previously thought in buffering the reflex sympathetic activation caused by static muscle contraction.
Mots-clé
Adult Blood Pressure *Exertion Heart Rate Humans Hydrogen-Ion Concentration Male Muscles/physiology Nitroprusside/pharmacology Phenylephrine/pharmacology Pressoreceptors/*physiology Reflex/physiology Sympathetic Nervous System/*physiology
Pubmed
Web of science
Création de la notice
25/01/2008 15:04
Dernière modification de la notice
03/03/2018 13:26
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