Neuromuscular blockade of slow twitch muscle fibres elevates muscle oxygen uptake and energy turnover during submaximal exercise in humans

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Standard

Neuromuscular blockade of slow twitch muscle fibres elevates muscle oxygen uptake and energy turnover during submaximal exercise in humans. / Krustrup, Peter; Secher, Niels; Relu, Mihai U.; Hellsten, Ylva; Söderlund, Karin; Bangsbo, Jens.

I: Journal of Physiology, Bind 586, Nr. 24, 2008, s. 6037-6048.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

Harvard

Krustrup, P, Secher, N, Relu, MU, Hellsten, Y, Söderlund, K & Bangsbo, J 2008, 'Neuromuscular blockade of slow twitch muscle fibres elevates muscle oxygen uptake and energy turnover during submaximal exercise in humans', Journal of Physiology, bind 586, nr. 24, s. 6037-6048. https://doi.org/10.1113/jphysiol.2008.158162

APA

Krustrup, P., Secher, N., Relu, M. U., Hellsten, Y., Söderlund, K., & Bangsbo, J. (2008). Neuromuscular blockade of slow twitch muscle fibres elevates muscle oxygen uptake and energy turnover during submaximal exercise in humans. Journal of Physiology, 586(24), 6037-6048. https://doi.org/10.1113/jphysiol.2008.158162

Vancouver

Krustrup P, Secher N, Relu MU, Hellsten Y, Söderlund K, Bangsbo J. Neuromuscular blockade of slow twitch muscle fibres elevates muscle oxygen uptake and energy turnover during submaximal exercise in humans. Journal of Physiology. 2008;586(24):6037-6048. https://doi.org/10.1113/jphysiol.2008.158162

Author

Krustrup, Peter ; Secher, Niels ; Relu, Mihai U. ; Hellsten, Ylva ; Söderlund, Karin ; Bangsbo, Jens. / Neuromuscular blockade of slow twitch muscle fibres elevates muscle oxygen uptake and energy turnover during submaximal exercise in humans. I: Journal of Physiology. 2008 ; Bind 586, Nr. 24. s. 6037-6048.

Bibtex

@article{2a03f390dbf711dd9473000ea68e967b,
title = "Neuromuscular blockade of slow twitch muscle fibres elevates muscle oxygen uptake and energy turnover during submaximal exercise in humans",
abstract = "We tested the hypothesis that a greater activation of fast-twitch (FT) fibres during dynamic exercise leads to a higher muscle oxygen uptake (VO2 ) and energy turnover as well as a slower muscle on-kinetics. Subjects performed one-legged knee-extensor exercise for 10 min at an intensity of 30 W without (CON) and with (CUR) arterial injections of the non-depolarizing neuromuscular blocking agent cisatracurium. In CUR, creatine phosphate (CP) was unaltered in slow twitch (ST) fibres and decreased (P < 0.05) by 28{\%} in FT fibres, whereas in CON, CP decreased (P < 0.05) by 33{\%} and 23{\%} in ST and FT fibres, respectively. From 127 s of exercise, muscle VO2 was higher (P < 0.05) in CUR compared to CON (425 +/- 25 (+/- S.E.M.) versus 332 +/- 30 ml min(-1)) and remained higher (P < 0.05) throughout exercise. Using monoexponential fitting, the time constant of the exercise-induced muscle VO2 response was slower (P < 0.05) in CUR than in CON (55 +/- 6 versus 33 +/- 5 s). During CUR and CON, muscle homogenate CP was lowered (P < 0.05) by 32 and 35{\%}, respectively, and also muscle lactate production was similar in CUR and CON (37.8 +/- 4.1 versus 35.2 +/- 6.2 mmol). Estimated total muscle ATP turnover was 19{\%} higher (P < 0.05) in CUR than in CON (1196 +/- 90 versus 1011 +/- 59 mmol) and true mechanical efficiency was lower (P < 0.05) in CUR than in CON (26.2 +/- 2.0 versus 30.9 +/- 1.5{\%}). In conclusion, the present findings provide evidence that FT fibres are less efficient than ST fibres in vivo at a contraction frequency of 1 Hz, and that the muscle VO2 kinetics is slowed by FT fibre activation.",
author = "Peter Krustrup and Niels Secher and Relu, {Mihai U.} and Ylva Hellsten and Karin S{\"o}derlund and Jens Bangsbo",
note = "CURIS 2008 5200 137",
year = "2008",
doi = "10.1113/jphysiol.2008.158162",
language = "English",
volume = "586",
pages = "6037--6048",
journal = "The Journal of Physiology",
issn = "0022-3751",
publisher = "Wiley-Blackwell",
number = "24",

}

RIS

TY - JOUR

T1 - Neuromuscular blockade of slow twitch muscle fibres elevates muscle oxygen uptake and energy turnover during submaximal exercise in humans

AU - Krustrup, Peter

AU - Secher, Niels

AU - Relu, Mihai U.

AU - Hellsten, Ylva

AU - Söderlund, Karin

AU - Bangsbo, Jens

N1 - CURIS 2008 5200 137

PY - 2008

Y1 - 2008

N2 - We tested the hypothesis that a greater activation of fast-twitch (FT) fibres during dynamic exercise leads to a higher muscle oxygen uptake (VO2 ) and energy turnover as well as a slower muscle on-kinetics. Subjects performed one-legged knee-extensor exercise for 10 min at an intensity of 30 W without (CON) and with (CUR) arterial injections of the non-depolarizing neuromuscular blocking agent cisatracurium. In CUR, creatine phosphate (CP) was unaltered in slow twitch (ST) fibres and decreased (P < 0.05) by 28% in FT fibres, whereas in CON, CP decreased (P < 0.05) by 33% and 23% in ST and FT fibres, respectively. From 127 s of exercise, muscle VO2 was higher (P < 0.05) in CUR compared to CON (425 +/- 25 (+/- S.E.M.) versus 332 +/- 30 ml min(-1)) and remained higher (P < 0.05) throughout exercise. Using monoexponential fitting, the time constant of the exercise-induced muscle VO2 response was slower (P < 0.05) in CUR than in CON (55 +/- 6 versus 33 +/- 5 s). During CUR and CON, muscle homogenate CP was lowered (P < 0.05) by 32 and 35%, respectively, and also muscle lactate production was similar in CUR and CON (37.8 +/- 4.1 versus 35.2 +/- 6.2 mmol). Estimated total muscle ATP turnover was 19% higher (P < 0.05) in CUR than in CON (1196 +/- 90 versus 1011 +/- 59 mmol) and true mechanical efficiency was lower (P < 0.05) in CUR than in CON (26.2 +/- 2.0 versus 30.9 +/- 1.5%). In conclusion, the present findings provide evidence that FT fibres are less efficient than ST fibres in vivo at a contraction frequency of 1 Hz, and that the muscle VO2 kinetics is slowed by FT fibre activation.

AB - We tested the hypothesis that a greater activation of fast-twitch (FT) fibres during dynamic exercise leads to a higher muscle oxygen uptake (VO2 ) and energy turnover as well as a slower muscle on-kinetics. Subjects performed one-legged knee-extensor exercise for 10 min at an intensity of 30 W without (CON) and with (CUR) arterial injections of the non-depolarizing neuromuscular blocking agent cisatracurium. In CUR, creatine phosphate (CP) was unaltered in slow twitch (ST) fibres and decreased (P < 0.05) by 28% in FT fibres, whereas in CON, CP decreased (P < 0.05) by 33% and 23% in ST and FT fibres, respectively. From 127 s of exercise, muscle VO2 was higher (P < 0.05) in CUR compared to CON (425 +/- 25 (+/- S.E.M.) versus 332 +/- 30 ml min(-1)) and remained higher (P < 0.05) throughout exercise. Using monoexponential fitting, the time constant of the exercise-induced muscle VO2 response was slower (P < 0.05) in CUR than in CON (55 +/- 6 versus 33 +/- 5 s). During CUR and CON, muscle homogenate CP was lowered (P < 0.05) by 32 and 35%, respectively, and also muscle lactate production was similar in CUR and CON (37.8 +/- 4.1 versus 35.2 +/- 6.2 mmol). Estimated total muscle ATP turnover was 19% higher (P < 0.05) in CUR than in CON (1196 +/- 90 versus 1011 +/- 59 mmol) and true mechanical efficiency was lower (P < 0.05) in CUR than in CON (26.2 +/- 2.0 versus 30.9 +/- 1.5%). In conclusion, the present findings provide evidence that FT fibres are less efficient than ST fibres in vivo at a contraction frequency of 1 Hz, and that the muscle VO2 kinetics is slowed by FT fibre activation.

U2 - 10.1113/jphysiol.2008.158162

DO - 10.1113/jphysiol.2008.158162

M3 - Journal article

C2 - 18955384

VL - 586

SP - 6037

EP - 6048

JO - The Journal of Physiology

JF - The Journal of Physiology

SN - 0022-3751

IS - 24

ER -

ID: 9539902