Made available in DSpace on 2021-06-25T12:19:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-07-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Pro-Reitoria de Pesquisa da Universidade Federal de Minas Gerais During overnight sleep, the longest postabsorptive and inactive phase of the day causes protein catabolism and loss. However, the daytime ingestion of dairy proteins has been shown to stimulate muscle protein synthesis and growth. This study compared the effects of pre-sleep supplementation of a protein blend (PB) composed of micellar casein (MCa) and whey protein (1:1) versus isolate MCa on the plasma levels of branched-chain amino acids (BCAAs) and the activation of the mechanistic target of rapamycin (mTOR) signaling, a critical intracellular pathway involved in the regulation of muscle protein synthesis. After 10 h of fasting during the active phase, rats were fed with a single dose of PB or MCa (5.6 g protein/kg of body mass) by gavage, and samples of blood and gastrocnemius muscle were collected at 30, 90, and 450 min. PB and MCa supplementations induced an increase (similar to 3-fold, P < 0.001) of plasma BCAAs at 30 and 90 min. Most importantly, the stimulatory phosphorylation levels of mTOR and its downstream target p70 ribosomal protein S6 kinase (p70S6K) were similarly higher (similar to 2.5-fold, P < 0.001) 30 and 90 min after MCa and PB. Plasma levels of leucine, isoleucine, valine, and overall BCAAs were correlated with the activation of mTOR (P < 0.001) and p70S6K (P < 0.001). MCa and PB supplementations before the inactive phase of rats resulted in an anabolic milieu in the skeletal muscle by inducing a transient increase in plasma BCAAs and a similar activation of the mTOR/p70S6K axis. State Univ Sao Paulo, Sch Pharmaceut Sci Araraquara, Dept Food & Nutr, Araraquara, SP, Brazil Univ Sao Paulo, Ribeirao Preto Med Sch, Dept Hlth Sci, Postgrad Program Rehabil & Funct Performance, Ribeirao Preto, SP, Brazil Univ Sao Paulo, Sch Phys Educ & Sport Ribeirao Preto, Ave Bandeirantes 3900, BR-14040907 Ribeirao Preto, SP, Brazil Univ Sao Paulo, Dept Physiol & Biochem & Immunol, Ribeirao Preto Med Sch, Ribeirao Preto, SP, Brazil Univ Fed Minas Gerais, Educ Sch Phys Educ Physiotherapy & Occupat Therap, Dept Phys Educ, Belo Horizonte, MG, Brazil State Univ Sao Paulo, Sch Pharmaceut Sci Araraquara, Dept Food & Nutr, Araraquara, SP, Brazil FAPESP: 12/18861 0 FAPESP: 2018/19107 3 CAPES: 001 Pro-Reitoria de Pesquisa da Universidade Federal de Minas Gerais: 27764*27