Adrenergic control of protein metabolism in skeletal muscle.
This review summarizes evidence indicating that the sympathetic nervous system, through hormonal and neurotransmitter actions, produces anabolic, protein-sparing effects on skeletal muscle protein metabolism. Studies are reviewed which indicate that catecholamines secreted by the adrenal medulla have an inhibitory effect on muscle Ca(2+)-dependent protein degradation independently of other hormones. In addition, norepinephrine released from adrenergic terminals may increase the rate of protein synthesis in oxidative muscles, leading to increased protein accretion. Evidence is also presented that these effects seem to be mediated by beta(2)-adrenoceptors and cyclic adenosine monophosphate-dependent pathways. The understanding of the precise mechanisms by which endogenous catecholamines promote muscle anabolic effects may bring new perspectives for efficient treatment of muscle-wasting conditions and enhancement of growth efficacy in farm species.
Navegantes
Luiz Carlos Carvalho
LC
Department of Physiology, School of Medicine, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
Migliorini
Renato Hélios
RH
do Carmo Kettelhut
Isis
I
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002395:Catecholamines / Q000378:metabolism; D006801:Humans; D009124:Muscle Proteins / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism; D013564:Sympathetic Nervous System / Q000502:physiology*
D002395:Catecholamines; D009124:Muscle Proteins; D002118:Calcium; D009638:Norepinephrine