Changes in PCr/Cr ratio in single characterized muscle fibre fragments after only a few maximal voluntary contractions in humans

J G M Beltman, A J Sargeant, H Haan, W van Mechelen, A de Haan

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

AIM: This methodological study investigated the number of brief maximal voluntary isometric contractions (MVC) needed to show evidence of fibre activation, as indicated by changes in the phosphocreatine to creatine (PCr/Cr) ratio.

METHODS: Subjects performed series of four, seven and/or 10 MVC (1 s on, 1 s off) of the m. quadriceps (60 degrees -flexion angle). Biopsy samples of the m. vastus lateralis were taken at rest and immediately post-exercise. Single muscle fibres were dissected from the freeze-dried samples and classified as types I, IIA or IIAX, using mATPase stainings. Fragments of characterized fibres were analysed for PCr and Cr content. Analyses of variance were performed to investigate changes in PCr/Cr per fibre group over time, followed by Bonferroni post-hoc test (P < 0.01). The fifth percentile of resting values of each fibre group was determined.

RESULTS: Mean PCr/Cr ratio after four, seven and 10 MVCs were significantly lower for all fibre groups (P < 0.01). The mean decreases were 44, 64 and 76%, respectively. However, only after seven and 10 contractions PCr/Cr ratios of all, but three type I and two type IIAX fibres, individual fibres were below the fifth percentile.

CONCLUSION: In very short duration exercise, involving seven brief maximal voluntary contractions, changes in the PCr/Cr ratio indicated activation of different characterized muscle fibre fragments. The results suggest that this approach may be useful for investigating the pattern of fibre type activation in exercise of very short duration.

Original languageEnglish
Pages (from-to)187-93
Number of pages7
JournalActa physiologica Scandinavica
Volume180
Issue number2
DOIs
Publication statusPublished - Feb 2004

Cite this

@article{96e7187242dc429d98d704d128cd66e7,
title = "Changes in PCr/Cr ratio in single characterized muscle fibre fragments after only a few maximal voluntary contractions in humans",
abstract = "AIM: This methodological study investigated the number of brief maximal voluntary isometric contractions (MVC) needed to show evidence of fibre activation, as indicated by changes in the phosphocreatine to creatine (PCr/Cr) ratio.METHODS: Subjects performed series of four, seven and/or 10 MVC (1 s on, 1 s off) of the m. quadriceps (60 degrees -flexion angle). Biopsy samples of the m. vastus lateralis were taken at rest and immediately post-exercise. Single muscle fibres were dissected from the freeze-dried samples and classified as types I, IIA or IIAX, using mATPase stainings. Fragments of characterized fibres were analysed for PCr and Cr content. Analyses of variance were performed to investigate changes in PCr/Cr per fibre group over time, followed by Bonferroni post-hoc test (P < 0.01). The fifth percentile of resting values of each fibre group was determined.RESULTS: Mean PCr/Cr ratio after four, seven and 10 MVCs were significantly lower for all fibre groups (P < 0.01). The mean decreases were 44, 64 and 76{\%}, respectively. However, only after seven and 10 contractions PCr/Cr ratios of all, but three type I and two type IIAX fibres, individual fibres were below the fifth percentile.CONCLUSION: In very short duration exercise, involving seven brief maximal voluntary contractions, changes in the PCr/Cr ratio indicated activation of different characterized muscle fibre fragments. The results suggest that this approach may be useful for investigating the pattern of fibre type activation in exercise of very short duration.",
keywords = "Adult, Chromatography, High Pressure Liquid/methods, Creatine/analysis, Exercise/physiology, Female, Humans, Isometric Contraction/physiology, Male, Mitochondria, Muscle, Muscle Fibers, Fast-Twitch/metabolism, Muscle Fibers, Skeletal/metabolism, Muscle Fibers, Slow-Twitch/metabolism, Muscle, Skeletal/metabolism, Phosphocreatine/analysis, Time Factors",
author = "Beltman, {J G M} and Sargeant, {A J} and H Haan and {van Mechelen}, W and {de Haan}, A",
year = "2004",
month = "2",
doi = "10.1046/j.0001-6772.2003.01257.x",
language = "English",
volume = "180",
pages = "187--93",
journal = "Acta physiologica Scandinavica",
issn = "0001-6772",
publisher = "John Wiley and Sons Ltd",
number = "2",

}

Changes in PCr/Cr ratio in single characterized muscle fibre fragments after only a few maximal voluntary contractions in humans. / Beltman, J G M; Sargeant, A J; Haan, H; van Mechelen, W; de Haan, A.

In: Acta physiologica Scandinavica, Vol. 180, No. 2, 02.2004, p. 187-93.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Changes in PCr/Cr ratio in single characterized muscle fibre fragments after only a few maximal voluntary contractions in humans

AU - Beltman, J G M

AU - Sargeant, A J

AU - Haan, H

AU - van Mechelen, W

AU - de Haan, A

PY - 2004/2

Y1 - 2004/2

N2 - AIM: This methodological study investigated the number of brief maximal voluntary isometric contractions (MVC) needed to show evidence of fibre activation, as indicated by changes in the phosphocreatine to creatine (PCr/Cr) ratio.METHODS: Subjects performed series of four, seven and/or 10 MVC (1 s on, 1 s off) of the m. quadriceps (60 degrees -flexion angle). Biopsy samples of the m. vastus lateralis were taken at rest and immediately post-exercise. Single muscle fibres were dissected from the freeze-dried samples and classified as types I, IIA or IIAX, using mATPase stainings. Fragments of characterized fibres were analysed for PCr and Cr content. Analyses of variance were performed to investigate changes in PCr/Cr per fibre group over time, followed by Bonferroni post-hoc test (P < 0.01). The fifth percentile of resting values of each fibre group was determined.RESULTS: Mean PCr/Cr ratio after four, seven and 10 MVCs were significantly lower for all fibre groups (P < 0.01). The mean decreases were 44, 64 and 76%, respectively. However, only after seven and 10 contractions PCr/Cr ratios of all, but three type I and two type IIAX fibres, individual fibres were below the fifth percentile.CONCLUSION: In very short duration exercise, involving seven brief maximal voluntary contractions, changes in the PCr/Cr ratio indicated activation of different characterized muscle fibre fragments. The results suggest that this approach may be useful for investigating the pattern of fibre type activation in exercise of very short duration.

AB - AIM: This methodological study investigated the number of brief maximal voluntary isometric contractions (MVC) needed to show evidence of fibre activation, as indicated by changes in the phosphocreatine to creatine (PCr/Cr) ratio.METHODS: Subjects performed series of four, seven and/or 10 MVC (1 s on, 1 s off) of the m. quadriceps (60 degrees -flexion angle). Biopsy samples of the m. vastus lateralis were taken at rest and immediately post-exercise. Single muscle fibres were dissected from the freeze-dried samples and classified as types I, IIA or IIAX, using mATPase stainings. Fragments of characterized fibres were analysed for PCr and Cr content. Analyses of variance were performed to investigate changes in PCr/Cr per fibre group over time, followed by Bonferroni post-hoc test (P < 0.01). The fifth percentile of resting values of each fibre group was determined.RESULTS: Mean PCr/Cr ratio after four, seven and 10 MVCs were significantly lower for all fibre groups (P < 0.01). The mean decreases were 44, 64 and 76%, respectively. However, only after seven and 10 contractions PCr/Cr ratios of all, but three type I and two type IIAX fibres, individual fibres were below the fifth percentile.CONCLUSION: In very short duration exercise, involving seven brief maximal voluntary contractions, changes in the PCr/Cr ratio indicated activation of different characterized muscle fibre fragments. The results suggest that this approach may be useful for investigating the pattern of fibre type activation in exercise of very short duration.

KW - Adult

KW - Chromatography, High Pressure Liquid/methods

KW - Creatine/analysis

KW - Exercise/physiology

KW - Female

KW - Humans

KW - Isometric Contraction/physiology

KW - Male

KW - Mitochondria, Muscle

KW - Muscle Fibers, Fast-Twitch/metabolism

KW - Muscle Fibers, Skeletal/metabolism

KW - Muscle Fibers, Slow-Twitch/metabolism

KW - Muscle, Skeletal/metabolism

KW - Phosphocreatine/analysis

KW - Time Factors

U2 - 10.1046/j.0001-6772.2003.01257.x

DO - 10.1046/j.0001-6772.2003.01257.x

M3 - Article

VL - 180

SP - 187

EP - 193

JO - Acta physiologica Scandinavica

JF - Acta physiologica Scandinavica

SN - 0001-6772

IS - 2

ER -