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The effect of cachectic myofiber metabolic properties on the resistance exercise‐induced hypertrophy response (884.21)
Author(s) -
Mangum Joshua,
Hardee Justin,
Puppa Melissa,
Carson James
Publication year - 2014
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.28.1_supplement.884.21
Subject(s) - cachexia , myocyte , medicine , muscle hypertrophy , endocrinology , wasting , sarcopenia , atrophy , muscle atrophy , cancer
Cancer cachexia disrupts skeletal muscle metabolism in conjunction with the loss of mass. There are no approved treatments for cachexia however our lab has shown treadmill exercise can suppress wasting. The purpose of this study was to determine the relationship between myofiber metabolic properties and eccentric exercise induced myofiber hypertrophy in mice with cancer cachexia. 16‐week male C57BL/6 (WT) and ApcMin/+ (Min) mice performed resistance exercise (RE) by stimulating the sciatic nerve for 7 sessions over 2 weeks. The tibialis anterior (TA) was contracted (EX) in one leg and the contralateral served as a control (CN). Histological analysis was used to examine myofiber SDH activity and PAS staining. Cachexia reduced TA mass and myofiber cross sectional area (CSA), RE was able to increase TA mass and myofiber CSA (EX > CN). RE induced a 26% increase in the frequency of high SDH activity fibers (OX), which were reduced with cachexia. While cachexia reduced the CSA of both OX and low SDH activity (GL) fibers, RE selectively induced hypertrophy of GL fibers. In addition, cachexia induced a 38% increase in the frequency of high glycogen content (HG) fibers. Although RE did not alter HG fiber frequency, RE induced hypertrophy of HG fibers. In summary, cachexia‐induced myofiber atrophy is independent of myofiber SDH activity. However, RE during cancer cachexia can increase OX fiber frequency and reverse GL fiber wasting. Grant Funding Source : Supported By R01CA121249