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Acute resistance exercise effects on IGF‐1 signaling cascade downstream pathway
Author(s) -
song taejeong,
Farrar Roger P
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.984.7
Subject(s) - pi3k/akt/mtor pathway , protein kinase b , muscle hypertrophy , medicine , endocrinology , downstream (manufacturing) , signal transduction , resistance training , mapk/erk pathway , chemistry , biology , microbiology and biotechnology , operations management , economics
Illuminating muscle hypertrophy mechanisms were main issues for over a decade. Now it is recognized that IGF‐1 downstream pathways are key molecules to increase muscle mass by activating gene transcription, protein synthesis and satellite cell proliferation and differentiation. But the activation timing and patterns of these pathways after resistance exercise is still controversial. The purpose of this study is to investigate the time course and trend of IGF‐1 signaling downstream after acute ladder climbing exercise. Male Sprague‐Dawley rats, 384g, were divided into control (CON), one bout exercised (1B) and three bouts exercised (3B) group and trained once per every three days then sacrificed at 3, 6 and 12 hours after last bout of exercise. Rats were fasted 3 hours before last exercise session and received standardized nutriment supplement via gavage (5m/kg) immediately after the last session. The ratio of FHL muscle mass (mg) to body weight (g) in 3B (1.69±0.1, P < 0.01) is increased significantly comparing to CON (1.49±0.05) and 1B (1.53±0.09). pAkt is peaked at 3B3 (+114%) and both pmTOR (+106%) and pp70S6K (+119%) are the most activated at 1B3. pERK shows peak at 3B12 (+80%). There are no changes of total Akt, mTOR, p70S6K and ERK. These data support that mTOR and p70S6K can be activated independent to AKT and are respond early during training.