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Sex‐based differences in contraction‐stimulated glucose uptake by mouse skeletal muscle
Author(s) -
Kang Ji,
Park Ji,
Dagoon Jason,
Schenk Simon
Publication year - 2021
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.2021.35.s1.04288
Subject(s) - contraction (grammar) , endocrinology , medicine , skeletal muscle , stimulation , soleus muscle , muscle contraction , insulin , chemistry , glucose uptake , biology
Contraction potently stimulates glucose uptake by skeletal muscle. While insulin‐stimulated glucose uptake by skeletal muscle is well known to be higher is females compared with males, whether this sex difference exists with contraction is unknown. The objective of this study was to address this gap in knowledge, and based on findings related to insulin, we hypothesized that contraction‐stimulated glucose uptake would be higher in female versus male mouse skeletal muscle. To address this hypothesis, in this study we used a radioactive 2‐deoxyglucose uptake (2DGU) approach to measure ex vivo glucose uptake in unstimulated (NoSTIM; i.e. rested) and electrically‐stimulated (STIM; 100 Hz, 2s train, 0.2ms pulse, 35V every 15 sec for 10 min) soleus and extensor digitorum longus (EDL) from ~15 week old male and female mice. Force production was measured throughout the protocol and 2DGU was measured in the NoSTIM and STIM muscles immediately after completing the stimulation protocol. As expected, force output decreased over the 10 min stimulation protocol, although there were no sex differences in maximal force or the rate of fatigue. Related to 2DGU, within each sex, 2DGU in the EDL and soleus was ~2.5‐fold higher in STIM vs. NoSTIM. Interestingly, contraction‐stimulated 2DGU (i.e. STIM 2DGU minus NoSTIM 2DGU) was ~1.3 fold higher in female vs. male, and this occurred in both soleus and EDL; this difference was due to greater 2DGU in STIM muscles, as 2DGU in NoSTIM muscles was not different between sexes. This difference in contraction‐stimulated 2DGU was not related total muscle stress during stimulation protocol, or the degree of activation/phosphorylation of the contraction‐activated kinases, AMP‐activated protein kinase and p38 mitogen‐activated protein kinase. Taken together, in line with previous work focused on insulin‐stimulated glucose uptake, this study demonstrates that contraction‐stimulated uptake by mouse skeletal muscle is greater in females compared to males, regardless of muscle type. This suggests that female muscle has an inherently greater capacity for contraction‐stimulated glucose uptake and future work will investigate the potential mechanisms underlying this sex‐based difference.