TY - UNPB

T1 - Regulation of Na+,K+-ATPase isoforms and phospholemman (FXYD1) in skeletal muscle fibre types by exercise training and cold-water immersion in men

AU - Christiansen, Danny

AU - Murphy, Robyn M

AU - Broach, James R

AU - Bangsbo, Jens

AU - McKenna, Michael J

AU - Bishop, David J

N1 - Posted in bioRxiv June 16, 2017

PY - 2017/6/16

Y1 - 2017/6/16

N2 - Little is understood about the fibre type-dependent regulation of Na+,K+-ATPase (NKA) isoforms by exercise training in humans. The main aim of this study was therefore to assess the impact of a period of repeated exercise sessions on NKA-isoform protein abundance in different skeletal muscle fibre types in men. Post-exercise cold-water immersion (CWI) has been reported to increase oxidative stress, which may be one mechanism underlying increases in NKA-isoform expression. Thus, a second aim was to evaluate the effect of CWI on training-induced modulation of NKA-isoform abundance. Vastus lateralis muscle biopsies were obtained from nineteen men at rest before (Pre) and after (Post) six weeks of intense interval cycling, with training sessions followed by passive rest (CON, n=7) or CWI (10°C; COLD, n=5). Training increased (p<0.05) the abundance of NKAα1 and NKAβ3 in both type I and type II fibres, NKAβ1 in type II fibres, but was without effect on NKAα2 and NKAα3 (p>0.05). Furthermore, training decreased FXYD1 protein content in type I fibres, which abolished its fibre type-specific expression detected at Pre (p<0.05). CWI was without impact on the responses to training (p>0.05). These results highlight that NKA isoforms are regulated in a fibre type-dependent fashion in response to intense training in humans. This may partly explain the improvement in muscle Na+/K+ handling after a period of intense training. CWI may be performed without adversely or favourably affecting training-induced changes in NKA-isoform abundance.

AB - Little is understood about the fibre type-dependent regulation of Na+,K+-ATPase (NKA) isoforms by exercise training in humans. The main aim of this study was therefore to assess the impact of a period of repeated exercise sessions on NKA-isoform protein abundance in different skeletal muscle fibre types in men. Post-exercise cold-water immersion (CWI) has been reported to increase oxidative stress, which may be one mechanism underlying increases in NKA-isoform expression. Thus, a second aim was to evaluate the effect of CWI on training-induced modulation of NKA-isoform abundance. Vastus lateralis muscle biopsies were obtained from nineteen men at rest before (Pre) and after (Post) six weeks of intense interval cycling, with training sessions followed by passive rest (CON, n=7) or CWI (10°C; COLD, n=5). Training increased (p<0.05) the abundance of NKAα1 and NKAβ3 in both type I and type II fibres, NKAβ1 in type II fibres, but was without effect on NKAα2 and NKAα3 (p>0.05). Furthermore, training decreased FXYD1 protein content in type I fibres, which abolished its fibre type-specific expression detected at Pre (p<0.05). CWI was without impact on the responses to training (p>0.05). These results highlight that NKA isoforms are regulated in a fibre type-dependent fashion in response to intense training in humans. This may partly explain the improvement in muscle Na+/K+ handling after a period of intense training. CWI may be performed without adversely or favourably affecting training-induced changes in NKA-isoform abundance.

KW - Faculty of Science

KW - Cold-water immersion

KW - Na+,K+-ATPase

KW - Single-fibre western blotting

U2 - 10.1101/151035

DO - 10.1101/151035

M3 - Preprint

BT - Regulation of Na+,K+-ATPase isoforms and phospholemman (FXYD1) in skeletal muscle fibre types by exercise training and cold-water immersion in men

PB - bioRxiv

ER -