title: The acute effects of strength, endurance and concurrent exercises on the Akt/mTOR/p70(S6K1) and AMPK signaling pathway responses in rat skeletal muscle.
abstract: The activation of competing intracellular pathways has been proposed to explain the reduced training adaptations after concurrent strength and endurance exercises (CE). The present study investigated the acute effects of CE, strength exercises (SE), and endurance exercises (EE) on phosphorylated/total ratios of selected AMPK and Akt/mTOR/p70(S6K1) pathway proteins in rats. Six animals per exercise group were killed immediately (0 h) and 2 h after each exercise mode. In addition, 6 animals in a non-exercised condition (NE) were killed on the same day and under the same conditions. The levels of AMPK, phospho-Thr(172)AMPK (p-AMPK), Akt, phospho-Ser(473)Akt (p-Akt), p70(S6K1), phospho-Thr(389)-p70(S6K1) (p-p70(S6K1)), mTOR, phospho-Ser(2448)mTOR (p-mTOR), and phospho-Thr(1462)-TSC2 (p-TSC2) expression were evaluated by immunoblotting in total plantaris muscle extracts. The only significant difference detected was an increase (i.e., 87%) in Akt phosphorylated/total ratio in the CE group 2 h after exercise compared to the NE group (P = 0.002). There were no changes in AMPK, TSC2, mTOR, or p70(S6K1) ratios when the exercise modes were compared to the NE condition (P ≥ 0.05). In conclusion, our data suggest that low-intensity and low-volume CE might not blunt the training-induced adaptations, since it did not activate competing intracellular pathways in an acute bout of strength and endurance exercises in rat skeletal muscle.
authors.affiliation: Escola de Educação Física e Esporte, Universidade de São Paulo, São Paulo, SP, Brasil. desouza.eo@gmail.com
authors.forename: E O
authors.initials: EO
authors.lastname: de Souza
authors.forename: V
authors.initials: V
authors.lastname: Tricoli
authors.forename: C
authors.initials: C
authors.lastname: Bueno Junior
authors.forename: M G
authors.initials: MG
authors.lastname: Pereira
authors.forename: P C
authors.initials: PC
authors.lastname: Brum
authors.forename: E M
authors.initials: EM
authors.lastname: Oliveira
authors.forename: H
authors.initials: H
authors.lastname: Roschel
authors.forename: M S
authors.initials: MS
authors.lastname: Aoki
authors.forename: C
authors.initials: C
authors.lastname: Urginowitsch
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism; D000818:Animals; D015151:Immunoblotting; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000201:enzymology* / Q000502:physiology; D010766:Phosphorylation; D010805:Physical Conditioning, Animal / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D011494:Protein Kinases / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism
chemical_list: D011494:Protein Kinases; C546845:mTOR protein, rat; D051057:Proto-Oncogene Proteins c-akt; D038762:Ribosomal Protein S6 Kinases, 70-kDa; D058570:TOR Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases