The rainbow trout muscle beta(2)-adrenoceptor system: Impact of beta(2)-agonist feeding.

Description
Titre: The rainbow trout muscle beta(2)-adrenoceptor system: Impact of beta(2)-agonist feeding.
Auteur(s): Lortie, Michel B.
Date: 2002
Résumé: Previous studies showed that beta2-adrenergic agonists (beta 2-AAs) enhanced muscle growth and reduced lipid deposition in animals of agricultural and economical importance, including teleost fish. The goal of the present study was to provide a mechanistic explanation underlying the reported beta2-AA-induced muscle growth in the rainbow trout (Oncorhynchus mykiss). Using radioligand binding assays and adenylyl cyclase/cAMP assays, this study characterized and demonstrated the presence of functional beta2-adrenoceptors (beta2-ARs) on red and white muscle membranes. Trout fed 40 ppm of two beta2-AAs (clenbuterol and ractopamine) for 30 days showed no significant changes in measured body and physiological parameters, beta2-AR numbers or beta2-AR mRNA levels in red or white muscle. However, treatments significantly increased fractional protein synthesis rates in red and white muscle. These studies demonstrate that beta2-AAs impact muscle protein synthesis by mechanisms initiated at the muscle membrane beta 2-AR and include the beta2-AR-signalling pathway in a teleost fish.
URL: http://hdl.handle.net/10393/6268
CollectionThèses, 1910 - 2005 // Theses, 1910 - 2005
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