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Increased FXYD1 and PGC‐1 α mRNA after blood flow‐restricted running is related to fibre type‐specific AMPK signalling and oxidative stress in human muscle
Author(s) -
Christiansen D.,
Murphy R. M.,
Bangsbo J.,
Stathis C. G.,
Bishop D. J.
Publication year - 2018
Publication title -
acta physiologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.591
H-Index - 116
eISSN - 1748-1716
pISSN - 1748-1708
DOI - 10.1111/apha.13045
Subject(s) - ampk , oxidative stress , medicine , endocrinology , hypoxia (environmental) , oxidative phosphorylation , skeletal muscle , chemistry , amp activated protein kinase , biology , protein kinase a , biochemistry , kinase , oxygen , organic chemistry
Aim This study explored the effects of blood flow restriction ( BFR ) on mRNA responses of PGC ‐1α (total, 1α1, and 1α4) and Na + ,K + ‐ ATP ase isoforms ( NKA ; α 1‐3 , β 1‐3 , and FXYD 1) to an interval running session and determined whether these effects were related to increased oxidative stress, hypoxia, and fibre type‐specific AMPK and Ca MKII signalling, in human skeletal muscle. Methods In a randomized, crossover fashion, 8 healthy men (26 ± 5 year and 57.4 ± 6.3 mL kg −1 min −1 ) completed 3 exercise sessions: without ( CON ) or with blood flow restriction ( BFR ), or in systemic hypoxia ( HYP , ~3250 m). A muscle sample was collected before (Pre) and after exercise (+0 hour, +3 hours) to quantify mRNA , indicators of oxidative stress ( HSP 27 protein in type I and II fibres, and catalase and HSP 70 mRNA ), metabolites, and α‐ AMPK Thr 172 /α‐ AMPK , ACC Ser 221 / ACC , Ca MKII Thr 287 /Ca MKII , and PLBS er 16 / PLB ratios in type I and II fibres. Results Muscle hypoxia (assessed by near‐infrared spectroscopy) was matched between BFR and HYP , which was higher than CON (~90% vs ~70%; P < .05). The mRNA levels of FXYD 1 and PGC ‐1α isoforms ( 1 α 1 and 1 α 4 ) increased in BFR only ( P < .05) and were associated with increases in indicators of oxidative stress and type I fibre ACC Ser 221 / ACC ratio, but dissociated from muscle hypoxia, lactate, and Ca MKII signalling. Conclusion Blood flow restriction augmented exercise‐induced increases in muscle FXYD 1 and PGC ‐1 α mRNA in men. This effect was related to increased oxidative stress and fibre type‐dependent AMPK signalling, but unrelated to the severity of muscle hypoxia, lactate accumulation, and modulation of fibre type‐specific Ca MKII signalling.