Influence of the renin-angiotensin system on sympathetic neurotransmission in canine skeletal muscle in vivo

Détails

ID Serval
serval:BIB_8D59995242AA
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Influence of the renin-angiotensin system on sympathetic neurotransmission in canine skeletal muscle in vivo
Périodique
Naunyn-Schmiedeberg's Archives of Pharmacology
Auteur(s)
Schwieler  J. H., Kahan  T., Nussberger  J., Hjemdahl  P.
ISSN
0028-1298 (Print)
Statut éditorial
Publié
Date de publication
02/1991
Volume
343
Numéro
2
Pages
166-72
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Feb
Résumé
The physiological importance of interactions between angiotensin II and sympathetic neurotransmission was studied in an in vivo model with constant flow blood perfused gracilis muscle in situ in dogs pretreated with desipramine and atropine. Sympathetic nerve stimulation-(2 and 8 Hz, 480 pulses) evoked over-flow of endogenous noradrenaline and vasoconstriction, and vasoconstrictor responses to exogenous noradrenaline (0.5 nmol, locally i.a.) were evaluated. Angiotensin converting enzyme inhibition by benazeprilat (10 mg i.v.; n = 8) reduced arterial angiotensin II levels from 26 +/- 8 to 2 +/- 1 pM and reduced mean arterial and basal muscle perfusion pressures. Subsequent resubstitution of angiotensin II (3, 30 and 90 ng kg-1 min-1 i.v.) elevated arterial angiotensin II dose-dependently (to 67 +/- 14, 622 +/- 63 and 1940 +/- 251 pM, respectively), as well as mean arterial and muscle perfusion pressures. Nerve stimulation-evoked noradrenaline overflow was unchanged following benazeprilat (-4 +/- 4 and +1 +/- 8% at 2 and 8 Hz, respectively) and during subsequent infusions of angiotensin II. Vasoconstrictor responses to nerve stimulation and exogenous noradrenaline were also uninfluenced by these treatments. Thus, angiotensin II did not enhance sympathetic neurotransmission at the postjunctional level. Another group of animals was pretreated with noncompetitive alpha-adrenoceptor blockade locally by phenoxybenzamine and benextramine (0.5 mg kg-1 i.a. of each; n = 7), which abolished vasoconstrictor responses to nerve stimulation. The effects of benazeprilat and subsequent angiotensin II infusions (3 and 30 ng kg-1 min-1 i.v.) on circulating angiotensin II levels, mean arterial and muscle perfusion pressures were similar in this group.(ABSTRACT TRUNCATED AT 250 WORDS)
Mots-clé
Angiotensin-Converting Enzyme Inhibitors/pharmacology Animals Benzazepines/pharmacology Dogs Electric Stimulation Female Muscles/*innervation Phenoxybenzamine/pharmacology Renin-Angiotensin System/*physiology Sympathetic Nervous System/drug effects/*physiology Synaptic Transmission/drug effects/*physiology
Pubmed
Web of science
Création de la notice
05/03/2008 17:39
Dernière modification de la notice
03/03/2018 19:15
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