The Effects of Acute Resistance Exercise on Apoptotic Signaling in Untrained Males: 123 June 1, 10: 00 AM - 10: 15 AM

• Published in: Medicine and science in sports and exercise 2016-05, Vol.48 (5S), p.15-15
• Main Authors: Townsend, Jeremy, Stout, Jeffrey R, Jajtner, Adam R, Church, David D, Oliveira, Leopnardo P, Beyer, Kyle B, Lamonica, Michael B, Riffe, Joshua J, Muddle, Tyler W, Wang, Ran
• Format: Article
• Language: English
• ISSN: 0195-9131
• DOI: 10.1249/01.mss.0000485054.98527.88

PURPOSE: To observe the effects of an acute lower-body resistance exercise protocol and subsequent recovery on intramuscular apoptotic signaling. METHODS: Twenty-eight untrained males (22.3 + or - 3.2 y, 1.7 + or - 0.1 m, 81.1 + or - 15.5 kg) were assigned to either a control (CON; n=11) or exercise group (EX; n=17) and completed a lower-body resistance exercise protocol consisting of the back squat, leg press, and leg extension exercise. Skeletal muscle microbiopsies were obtained from the vastus lateralis pre-exercise (PRE), 1-hour (1HR), 5-hour (5HR), and 48-hours (48HR) post-resistance exercise. Multiplex signaling assay kits (EMD Millipore, Billerica, MA, USA) were used to quantify the total protein (Caspase-3,-8,-9) or phosphorylation status of proteins (JNK, FADD, p53, BAD, Bcl-2) specific to apoptotic signaling pathways using MAGPIX(R) (Luminex, Austin, TX, USA). Mann Whitney U analysis was used to determine the effects of the exercise bout on intramuscular signaling. Additionally, change scores were analyzed by magnitude based inferences to determine a mechanistic interpretation. RESULTS: Mann-Whitney U analysis revealed that resistance exercise increased JNK phosphorylation at 1H (p=0.001) and 5H (p=0.022), and FADD phosphorylation at 1H (p=0.029). No other differences observed between groups. Magnitude based inferences revealed a "Likely" increase in total Caspase 3 from PRE-5H and from PRE-48H. JNK phosphorylation was "Most Likely" increased from PRE-1H and PRE-5H and FADD was "Likely" increased from PRE-1H. BAD was "Very Likely" increased from PRE-5H and Bcl-2 was "Most Likely" increased from PRE-1H and "Likely" increased" from PRE-5H. CONCLUSION: These data show that apoptotic signaling is upregulated in response to a typical resistance exercise protocol, providing additional insight into the physiological mechanisms involved in skeletal muscle remodeling following resistance exercise.