Abundance of ClC-1 chloride channel in human skeletal muscle: fiber type specific differences and effect of training

作者:Thomassen Martin*; Hostrup Morten; Murphy Robyn M; Cromer Brett A; Skovgaard Casper; Gunnarsson Thomas P; Christensen Peter M; Bang**o Jens
来源:Journal of Applied Physiology, 2018, 125(2): 470-478.
DOI:10.1152/japplphysiol.01042.2017

摘要

Cl- channel protein 1 (ClC-1) may be important for excitability and contractility in skeletal muscle, but CIC-1 abundance has not been examined in human muscle. The aim of the present study was to examine ClC-1 abundance in human skeletal muscle, including fiber type specific differences and the effect of exercise training. A commercially available antibody was tested with positive and negative control tissue, and it recognized specifically ClC-1 in the range from 100 to 150 kDa. Abundance of ClC-1 was 38% higher (P < 0.01) in fast twitch Type Ha muscle fibers than in slow twitch Type I. Muscle ClC-1 abundance did not change with 4 wk of training consisting of 30 min cycling at 85% of maximal heart rate (HRmax) and 3 x 30-s all out sprints or during a 7-wk training period with 10-12 x 30 s uphill cycling and 4-5 x similar to 4 min cycling at 90%-95% of HRmax. ClC-1 abundance correlated negatively (P < 0.01) with maximal oxygen consumption (r = -0.552) and incremental exercise performance (r = -0.546). In addition, trained cyclists had lower (P < 0.01) ClC-1 abundance than lesser trained individuals. The present observations indicate that a low abundance of muscle ClC-1 may be beneficial for exercise performance, but the role of abundance and regulation of ClC-1 in skeletal muscle of humans with respect to exercise performance and trainability need to be elucidated.
NEW & NOTEWORTHY Abundance of the Cl- channel protein 1 (ClC-1) chloride channel may be important for excitability and contractility in human skeletal muscle and may therefore have implications for fatigue development. In this study, we confirmed ClC-1 specificity for a commercially available antibody, and this study is first to our knowledge to determine ClC-1 protein abundance in human muscle by Western blotting. We observed that abundance of ClC-1 was higher in fast compared with slow twitch fibers and lower in trained individuals than in recreationally active.

  • 出版日期2018-8