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Study · Measured the body's own peptide · 2003

4 results

Expression of IGF-I splice variants in young and old human skeletal muscle after high resistance exercise.

Hameed M, Orrell RW, Cobbold M, Goldspink G, Harridge SD

The Journal of physiology20 Dec 2002Cited by 274 (Europe PMC)

PMID12562960 (opens in a new tab)DOI10.1113/jphysiol.2002.032136 (opens in a new tab)PepBankPUB-12562960
Publisher pagePubMedAsk about this study
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Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study4

No result from this study comes from a test of the peptide.

Natural levels measured4

These results measure the body's own peptide. Nobody was given the peptide. They are not evidence about taking it. They are left out of key results, evidence counts and charts.

  1. 01HumanEndogenous levelObservational studyMechanism

    In human skeletal muscle at rest, MGF mRNA levels were approximately 100-fold lower than IGF-IEa mRNA levels.

    In plain wordsAt rest, the body's own MGF levels in muscle were about 100 times lower than those of another IGF-I form.

    Peptide
    MGF / PEG-MGF
    Outcome
    Not applicableResting MGF versus IGF-IEa mRNA level
    Study

    n = 15

    Comparator
    IGF-IEa
    Outcome group
    Growth hormone and IGF-1 · Musculoskeletal

    Measurements

    Fold difference vs IGF-IEa
    ≈ 100 fold
    resting muscle

    Source sentences

    Summary
    The resting levels of MGF were significantly (approximately 100-fold) lower than those of the IGF-IEa isoform.
    2 context sentences
    Summary · context
    Subjects (eight young, aged 25-36 years, and seven elderly, aged 70-82 years) completed 10 sets of six repetitions of single legged knee extensor exercise at 80 % of their one repetition maximum.
    Summary · context
    Muscle biopsy samples were obtained from the quadriceps muscle of both the control and exercised legs 2.5 h after completion of the exercise bout.

    This result measures the body's own MGF / PEG-MGF. Nobody was given the peptide. It is not evidence about taking it.

  2. 02HumanEndogenous levelObservational studyMechanism

    Resting MGF mRNA levels did not differ between young and elderly subjects.

    In plain wordsAt rest, the body's own MGF levels in muscle were similar in young and elderly people.

    Peptide
    MGF / PEG-MGF
    Outcome
    No significant changeResting MGF levels, young versus elderly
    Study

    n = 15

    Comparator
    Elderly subjects
    Outcome group
    Growth hormone and IGF-1 · Musculoskeletal

    Source sentences

    Summary
    No difference was observed between the resting levels of the two isoforms between the two subject groups.
    2 context sentences
    Summary · context
    Subjects (eight young, aged 25-36 years, and seven elderly, aged 70-82 years) completed 10 sets of six repetitions of single legged knee extensor exercise at 80 % of their one repetition maximum.
    Summary · context
    Muscle biopsy samples were obtained from the quadriceps muscle of both the control and exercised legs 2.5 h after completion of the exercise bout.

    This result measures the body's own MGF / PEG-MGF. Nobody was given the peptide. It is not evidence about taking it.

  3. 03HumanEndogenous levelObservational studyMechanism

    In young subjects, high resistance exercise significantly increased MGF mRNA in skeletal muscle.

    In plain wordsIn young people, heavy exercise raised the body's own MGF activity in muscle.

    Peptide
    MGF / PEG-MGF
    Outcome
    IncreaseMGF mRNA after high resistance exercise, young
    Study

    n = 8

    Outcome group
    Growth hormone and IGF-1 · Musculoskeletal

    Source sentences

    Summary
    High resistance exercise resulted in a significant increase in MGF mRNA in the young, but not in the elderly subjects.
    2 context sentences
    Summary · context
    Subjects (eight young, aged 25-36 years, and seven elderly, aged 70-82 years) completed 10 sets of six repetitions of single legged knee extensor exercise at 80 % of their one repetition maximum.
    Summary · context
    Muscle biopsy samples were obtained from the quadriceps muscle of both the control and exercised legs 2.5 h after completion of the exercise bout.

    This result measures the body's own MGF / PEG-MGF. Nobody was given the peptide. It is not evidence about taking it.

  4. 04HumanEndogenous levelObservational studyMechanism

    In elderly subjects, high resistance exercise did not significantly increase MGF mRNA in skeletal muscle.

    In plain wordsIn elderly people, heavy exercise did not raise the body's own MGF activity in muscle.

    Peptide
    MGF / PEG-MGF
    Outcome
    No significant changeMGF mRNA after high resistance exercise, elderly
    Study

    n = 7

    Outcome group
    Growth hormone and IGF-1 · Musculoskeletal

    Source sentences

    Summary
    High resistance exercise resulted in a significant increase in MGF mRNA in the young, but not in the elderly subjects.
    2 context sentences
    Summary · context
    Subjects (eight young, aged 25-36 years, and seven elderly, aged 70-82 years) completed 10 sets of six repetitions of single legged knee extensor exercise at 80 % of their one repetition maximum.
    Summary · context
    Muscle biopsy samples were obtained from the quadriceps muscle of both the control and exercised legs 2.5 h after completion of the exercise bout.

    This result measures the body's own MGF / PEG-MGF. Nobody was given the peptide. It is not evidence about taking it.

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Registered trials1

Trials this study reports on, or that list this study as a reference. Registry data from ClinicalTrials.gov.

1 trial · 1 completed · source ClinicalTrials.gov (opens in a new tab)

CompletedNot applicableNCT00635440

Randomized, Controlled Study to Investigate the Effect of Neuromuscular Electrical Stimulation (NMES) on Muscle Metabolism of Abdominal Surgical Patients

Medical University of Viennan = 26Start Dec 2005

Muscular Atrophy

Trial pageClinicalTrials.govUpdated 13 Mar 2008

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

  1. Version 2Current

    13 Oct 2026, 21:44 UTC

    Study results updated

  2. Version 1

    13 Oct 2026, 16:31 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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