Skip to content

Study · Measured the body's own peptide · 2005

3 results

Impact of resistance loading on myostatin expression and cell cycle regulation in young and older men and women.

Kim JS, Cross JM, Bamman MM

American journal of physiology. Endocrinology and metabolism11 Jan 2005Cited by 180 (Europe PMC)

PMID15644458 (opens in a new tab)DOI10.1152/ajpendo.00464.2004 (opens in a new tab)PepBankPUB-15644458
Publisher pagePubMedAsk about this study
Jump to 3 results

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 study3

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

Natural levels measured3

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 young and older men and women, muscle MGF mRNA was 49% higher 24 hours after a bout of resistance loading.

    In plain wordsIn adults, the body's own muscle MGF messenger RNA was higher 24 hours after one bout of resistance exercise.

    Peptide
    MGF / PEG-MGF
    Outcome
    IncreaseMuscle MGF mRNA 24 h after resistance loading, all participants
    Study

    n = 38

    Comparator
    Before loading
    Outcome group
    Exercise and physical function · Musculoskeletal

    Measurements

    MGF mRNA change
    49%
    all participants, 24 h after loading

    Source sentences

    Summary
    A load effect was found for four transcripts (P < 0.005) including myostatin, cyclin D1, p27kip, and MGF as mRNA levels decreased for myostatin (-44%) and p27kip (-16%) and increased for cyclin D1 (34%) and MGF (49%).
    1 context sentence
    Summary · context
    Twenty young (Y; 20-35 yr, 10 YF, 10 YM) and 18 O (60-75 yr, 9 OF, 9 OM) consented to vastus lateralis biopsy before and 24 h after a bout of RL (3 sets x 8-12 repetitions to volitional fatigue of squat, leg press, knee extension).

    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

    In young men, muscle MGF mRNA increased 91% after resistance loading.

    In plain wordsIn young men, the body's own muscle MGF messenger RNA rose after resistance exercise.

    Peptide
    MGF / PEG-MGF
    Outcome
    IncreaseMuscle MGF mRNA after resistance loading, young men
    Study

    n = 10

    Comparator
    Before loading
    Outcome group
    Exercise and physical function · Musculoskeletal

    Measurements

    MGF mRNA change
    91%
    young men

    Source sentences

    Summary
    Post hoc testing within groups revealed a significant increase in MGF after RL in YM only (91%, P < 0.05).
    1 context sentence
    Summary · context
    Twenty young (Y; 20-35 yr, 10 YF, 10 YM) and 18 O (60-75 yr, 9 OF, 9 OM) consented to vastus lateralis biopsy before and 24 h after a bout of RL (3 sets x 8-12 repetitions to volitional fatigue of squat, leg press, knee extension).

    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 women, older men and older women, post hoc testing showed no significant MGF increase after resistance loading, because it was significant in young men only.

    In plain wordsIn young women, older men and older women, the body's own muscle MGF messenger RNA did not clearly rise after resistance exercise.

    Peptide
    MGF / PEG-MGF
    Outcome
    No significant changeMuscle MGF mRNA after resistance loading, other age and sex groups
    Study

    n: not reported in source

    Comparator
    Before loading
    Outcome group
    Exercise and physical function · Musculoskeletal

    Source sentences

    Summary
    Post hoc testing within groups revealed a significant increase in MGF after RL in YM only (91%, P < 0.05).
    1 context sentence
    Summary · context
    Twenty young (Y; 20-35 yr, 10 YF, 10 YM) and 18 O (60-75 yr, 9 OF, 9 OM) consented to vastus lateralis biopsy before and 24 h after a bout of RL (3 sets x 8-12 repetitions to volitional fatigue of squat, leg press, knee extension).

    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.

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.

PepBank is a research reference. Talk to a doctor before you use any peptide.