β-Adrenergic modulation of skeletal muscle contraction: key role of excitation-contraction coupling.

Détails

ID Serval
serval:BIB_E5C34134930B
Type
Article: article d'un périodique ou d'un magazine.
Sous-type
Synthèse (review): revue aussi complète que possible des connaissances sur un sujet, rédigée à partir de l'analyse exhaustive des travaux publiés.
Collection
Publications
Institution
Titre
β-Adrenergic modulation of skeletal muscle contraction: key role of excitation-contraction coupling.
Périodique
Journal of Physiology
Auteur(s)
Cairns S.P., Borrani F.
ISSN
1469-7793 (Electronic)
ISSN-L
0022-3751
Statut éditorial
Publié
Date de publication
2015
Peer-reviewed
Oui
Volume
593
Numéro
21
Pages
4713-4727
Langue
anglais
Notes
Publication types: Journal Article ; Review
Publication Status: ppublish
Résumé
Our aim is to describe the acute effects of catecholamines/β-adrenergic agonists on contraction of non-fatigued skeletal muscle in animals and humans, and explain the mechanisms involved. Adrenaline/β-agonists (0.1-30 μm) generally augment peak force across animal species (positive inotropic effect) and abbreviate relaxation of slow-twitch muscles (positive lusitropic effect). A peak force reduction also occurs in slow-twitch muscles in some conditions. β2 -Adrenoceptor stimulation activates distinct cyclic AMP-dependent protein kinases to phosphorylate multiple target proteins. β-Agonists modulate sarcolemmal processes (increased resting membrane potential and action potential amplitude) via enhanced Na(+) -K(+) pump and Na(+) -K(+) -2Cl(-) cotransporter function, but this does not increase force. Myofibrillar Ca(2+) sensitivity and maximum Ca(2+) -activated force are unchanged. All force potentiation involves amplified myoplasmic Ca(2+) transients consequent to increased Ca(2+) release from sarcoplasmic reticulum (SR). This unequivocally requires phosphorylation of SR Ca(2+) release channels/ryanodine receptors (RyR1) which sensitize the Ca(2+) -induced Ca(2+) release mechanism. Enhanced trans-sarcolemmal Ca(2+) influx through phosphorylated voltage-activated Ca(2+) channels contributes to force potentiation in diaphragm and amphibian muscle, but not mammalian limb muscle. Phosphorylation of phospholamban increases SR Ca(2+) pump activity in slow-twitch fibres but does not augment force; this process accelerates relaxation and may depress force. Greater Ca(2+) loading of SR may assist force potentiation in fast-twitch muscle. Some human studies show no significant force potentiation which appears to be related to the β-agonist concentration used. Indeed high-dose β-agonists (∼0.1 μm) enhance SR Ca(2+) -release rates, maximum voluntary contraction strength and peak Wingate power in trained humans. The combined findings can explain how adrenaline/β-agonists influence muscle performance during exercise/stress in humans.
Mots-clé
Adenylyl Cyclases/metabolism, Adrenergic beta-Agonists/pharmacology, Animals, Cyclic AMP-Dependent Protein Kinases/metabolism, Excitation Contraction Coupling, Humans, Ion Channels/metabolism, Muscle, Skeletal/drug effects, Muscle, Skeletal/metabolism
Pubmed
Web of science
Open Access
Oui
Création de la notice
01/12/2015 17:47
Dernière modification de la notice
20/08/2019 16:09
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