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Study · Animal study (in vivo) · rat · 2018

13 results

Effect of the Orally Active Growth Hormone Secretagogue MK-677 on Somatic Growth in Rats.

Lee J, Kwon A, Chae HW, Lee WJ, Kim TH, Kim HS

Yonsei medical journal1 Dec 2018Cited by 2 (Europe PMC)

PMID30450851 (opens in a new tab)PMCIDPMC6240568 (opens in a new tab)DOI10.3349/ymj.2018.59.10.1174 (opens in a new tab)PepBankPUB-30450851
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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: CC BY-NC. Results still quote short attributed sentences.

Results from this study13

13 results from studies that gave the peptide. No result from this study comes from people.

  1. 01AnimalAnimal study (in vivo)Efficacy outcome

    In rats, oral MK‑677 increased peak GH concentrations 1.8-fold compared with baseline.

    In plain wordsIn rats, oral MK‑677 increased peak growth hormone compared with baseline.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    IncreasePeak GH concentration
    Study

    ratn: not reported in source

    Rats
    Comparator
    Baseline
    Outcome group
    Growth hormone and IGF-1 · Endocrine and hormones
    Studied dose
    4 mg/kg · oralAs given in this study (rat).

    Measurements

    Peak GH increase
    1.8 fold
    versus baseline

    Source sentences

    Summary
    Oral administration of MK-677 at 4 mg/kg increased peak GH concentrations by 1.8-fold, compared to baseline.
    1 context sentence
    Summary · context
    Body weight, body length, tibia length, epiphyseal plate width, and serum levels of insulin-like growth factor (IGF)-I were measured after oral administration of 4 mg/kg of MK-677 for 6 weeks to investigate growth-promoting effects.
  2. 02AnimalAnimal study (in vivo)Efficacy outcome

    In rats, oral MK‑677 for 6 weeks did not increase body growth.

    In plain wordsIn rats, oral MK‑677 did not increase body growth during 6 weeks.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    No significant changeBody growth
    Study

    ratn: not reported in source

    Rats
    Outcome group
    Linear growth · Musculoskeletal
    Studied dose
    4 mg/kg · oral · 6 weeksAs given in this study (rat).

    Source sentences

    Summary
    However, oral administration of MK-677 for 6 weeks did not increase body growth or serum levels of IGF-I.
    1 context sentence
    Summary · context
    Body weight, body length, tibia length, epiphyseal plate width, and serum levels of insulin-like growth factor (IGF)-I were measured after oral administration of 4 mg/kg of MK-677 for 6 weeks to investigate growth-promoting effects.
  3. 03AnimalAnimal study (in vivo)Efficacy outcome

    In rats, oral MK‑677 for 6 weeks did not increase serum IGF-I.

    In plain wordsIn rats, oral MK‑677 did not increase serum IGF-I during 6 weeks.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    No significant changeSerum IGF-I
    Study

    ratn: not reported in source

    Rats
    Outcome group
    Growth hormone and IGF-1 · Endocrine and hormones
    Studied dose
    4 mg/kg · oral · 6 weeksAs given in this study (rat).

    Source sentences

    Summary
    However, oral administration of MK-677 for 6 weeks did not increase body growth or serum levels of IGF-I.
    1 context sentence
    Summary · context
    Body weight, body length, tibia length, epiphyseal plate width, and serum levels of insulin-like growth factor (IGF)-I were measured after oral administration of 4 mg/kg of MK-677 for 6 weeks to investigate growth-promoting effects.
  4. 04AnimalAnimal study (in vivo)Efficacy outcome

    In rats, the GH response to MK‑677 disappeared after 6 weeks of treatment.

    In plain wordsIn rats, the growth hormone response to MK‑677 disappeared after 6 weeks.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    DecreaseGH response after prolonged treatment
    Study

    ratn: not reported in source

    Rats
    Outcome group
    Growth hormone and IGF-1 · Endocrine and hormones
    Studied dose
    4 mg/kg · oral · 6 weeksAs given in this study (rat).

    Source sentences

    Summary
    At 6 weeks after treatment, the GH response to MK-677 was abolished.
    1 context sentence
    Summary · context
    Body weight, body length, tibia length, epiphyseal plate width, and serum levels of insulin-like growth factor (IGF)-I were measured after oral administration of 4 mg/kg of MK-677 for 6 weeks to investigate growth-promoting effects.
  5. 05AnimalAnimal study (in vivo)Mechanism

    In rats, pituitary GH mRNA did not differ between MK‑677 and control groups.

    In plain wordsIn rats, pituitary growth hormone gene expression did not differ between MK‑677 and control groups.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    No significant changePituitary GH mRNA
    Study

    ratn: not reported in source

    Rats
    Comparator
    Control group
    Outcome group
    Growth hormone and IGF-1 · Endocrine and hormones
    Studied dose
    4 mg/kg · oral · 6 weeksAs given in this study (rat).

    Source sentences

    Summary
    Pituitary GH mRNA and hypothalamic GH-releasing hormone mRNA, and GH secretagogue receptor (GHSR) mRNA expression in the pituitary and hypothalamus did not differ between the control and treatment group.
    1 context sentence
    Summary · context
    Body weight, body length, tibia length, epiphyseal plate width, and serum levels of insulin-like growth factor (IGF)-I were measured after oral administration of 4 mg/kg of MK-677 for 6 weeks to investigate growth-promoting effects.
  6. 06AnimalAnimal study (in vivo)Mechanism

    In rats, hypothalamic GH-releasing hormone mRNA did not differ between MK‑677 and control groups.

    In plain wordsIn rats, hypothalamic growth hormone releasing hormone gene expression did not differ between MK‑677 and control groups.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    No significant changeHypothalamic GH-releasing hormone mRNA
    Study

    ratn: not reported in source

    Rats
    Comparator
    Control group
    Outcome group
    Growth hormone and IGF-1 · Endocrine and hormones
    Studied dose
    4 mg/kg · oral · 6 weeksAs given in this study (rat).

    Source sentences

    Summary
    Pituitary GH mRNA and hypothalamic GH-releasing hormone mRNA, and GH secretagogue receptor (GHSR) mRNA expression in the pituitary and hypothalamus did not differ between the control and treatment group.
    1 context sentence
    Summary · context
    Body weight, body length, tibia length, epiphyseal plate width, and serum levels of insulin-like growth factor (IGF)-I were measured after oral administration of 4 mg/kg of MK-677 for 6 weeks to investigate growth-promoting effects.
  7. 07AnimalAnimal study (in vivo)Mechanism

    In rats, pituitary GHSR mRNA did not differ between MK‑677 and control groups.

    In plain wordsIn rats, pituitary GHSR gene expression did not differ between MK‑677 and control groups.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    No significant changePituitary GHSR mRNA
    Study

    ratn: not reported in source

    Rats
    Comparator
    Control group
    Outcome group
    Growth hormone and IGF-1 · Endocrine and hormones
    Studied dose
    4 mg/kg · oral · 6 weeksAs given in this study (rat).

    Source sentences

    Summary
    Pituitary GH mRNA and hypothalamic GH-releasing hormone mRNA, and GH secretagogue receptor (GHSR) mRNA expression in the pituitary and hypothalamus did not differ between the control and treatment group.
    1 context sentence
    Summary · context
    Body weight, body length, tibia length, epiphyseal plate width, and serum levels of insulin-like growth factor (IGF)-I were measured after oral administration of 4 mg/kg of MK-677 for 6 weeks to investigate growth-promoting effects.
  8. 08AnimalAnimal study (in vivo)Mechanism

    In rats, hypothalamic GHSR mRNA did not differ between MK‑677 and control groups.

    In plain wordsIn rats, hypothalamic GHSR gene expression did not differ between MK‑677 and control groups.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    No significant changeHypothalamic GHSR mRNA
    Study

    ratn: not reported in source

    Rats
    Comparator
    Control group
    Outcome group
    Growth hormone and IGF-1 · Endocrine and hormones
    Studied dose
    4 mg/kg · oral · 6 weeksAs given in this study (rat).

    Source sentences

    Summary
    Pituitary GH mRNA and hypothalamic GH-releasing hormone mRNA, and GH secretagogue receptor (GHSR) mRNA expression in the pituitary and hypothalamus did not differ between the control and treatment group.
    1 context sentence
    Summary · context
    Body weight, body length, tibia length, epiphyseal plate width, and serum levels of insulin-like growth factor (IGF)-I were measured after oral administration of 4 mg/kg of MK-677 for 6 weeks to investigate growth-promoting effects.
  9. 09AnimalAnimal study (in vivo)Mechanism

    In rats, hypothalamic SST mRNA increased with MK‑677 compared with controls.

    In plain wordsIn rats, hypothalamic somatostatin gene expression increased with MK‑677 compared with controls.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    IncreaseHypothalamic SST mRNA
    Study

    ratn: not reported in source

    Rats
    Comparator
    Control group
    Outcome group
    Growth hormone and IGF-1 · Endocrine and hormones
    Studied dose
    4 mg/kg · oral · 6 weeksAs given in this study (rat).

    Source sentences

    Summary
    Somatostatin (SST) mRNA expression in the hypothalamus was markedly increased in the treatment group, whereas SST receptor (SSTR)-2 mRNA expression in the pituitary gland was decreased.
    1 context sentence
    Summary · context
    Body weight, body length, tibia length, epiphyseal plate width, and serum levels of insulin-like growth factor (IGF)-I were measured after oral administration of 4 mg/kg of MK-677 for 6 weeks to investigate growth-promoting effects.
  10. 10AnimalAnimal study (in vivo)Mechanism

    In rats, pituitary SSTR-2 mRNA decreased with MK‑677 compared with controls.

    In plain wordsIn rats, pituitary somatostatin receptor-2 gene expression decreased with MK‑677 compared with controls.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    DecreasePituitary SSTR-2 mRNA
    Study

    ratn: not reported in source

    Rats
    Comparator
    Control group
    Outcome group
    Growth hormone and IGF-1 · Endocrine and hormones
    Studied dose
    4 mg/kg · oral · 6 weeksAs given in this study (rat).

    Source sentences

    Summary
    Somatostatin (SST) mRNA expression in the hypothalamus was markedly increased in the treatment group, whereas SST receptor (SSTR)-2 mRNA expression in the pituitary gland was decreased.
    1 context sentence
    Summary · context
    Body weight, body length, tibia length, epiphyseal plate width, and serum levels of insulin-like growth factor (IGF)-I were measured after oral administration of 4 mg/kg of MK-677 for 6 weeks to investigate growth-promoting effects.
  11. 11AnimalAnimal study (in vivo)Mechanism

    In rats, hypothalamic GHSR protein did not change with MK‑677 compared with controls.

    In plain wordsIn rats, hypothalamic GHSR protein did not change with MK‑677 compared with controls.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    No significant changeHypothalamic GHSR protein
    Study

    ratn: not reported in source

    Rats
    Comparator
    Control group
    Outcome group
    Growth hormone and IGF-1 · Endocrine and hormones
    Studied dose
    4 mg/kg · oral · 6 weeksAs given in this study (rat).

    Source sentences

    Summary
    Protein expression of hypothalamic GHSR, SST, and pituitary SSTR-2 showed patterns similar to those for mRNA expression.
    2 context sentences
    Summary · context
    Pituitary GH mRNA and hypothalamic GH-releasing hormone mRNA, and GH secretagogue receptor (GHSR) mRNA expression in the pituitary and hypothalamus did not differ between the control and treatment group.
    Summary · context
    Body weight, body length, tibia length, epiphyseal plate width, and serum levels of insulin-like growth factor (IGF)-I were measured after oral administration of 4 mg/kg of MK-677 for 6 weeks to investigate growth-promoting effects.
  12. 12AnimalAnimal study (in vivo)Mechanism

    In rats, hypothalamic SST protein increased with MK‑677 compared with controls.

    In plain wordsIn rats, hypothalamic somatostatin protein increased with MK‑677 compared with controls.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    IncreaseHypothalamic SST protein
    Study

    ratn: not reported in source

    Rats
    Comparator
    Control group
    Outcome group
    Growth hormone and IGF-1 · Endocrine and hormones
    Studied dose
    4 mg/kg · oral · 6 weeksAs given in this study (rat).

    Source sentences

    Summary
    Protein expression of hypothalamic GHSR, SST, and pituitary SSTR-2 showed patterns similar to those for mRNA expression.
    2 context sentences
    Summary · context
    Somatostatin (SST) mRNA expression in the hypothalamus was markedly increased in the treatment group, whereas SST receptor (SSTR)-2 mRNA expression in the pituitary gland was decreased.
    Summary · context
    Body weight, body length, tibia length, epiphyseal plate width, and serum levels of insulin-like growth factor (IGF)-I were measured after oral administration of 4 mg/kg of MK-677 for 6 weeks to investigate growth-promoting effects.
  13. 13AnimalAnimal study (in vivo)Mechanism

    In rats, pituitary SSTR-2 protein decreased with MK‑677 compared with controls.

    In plain wordsIn rats, pituitary somatostatin receptor-2 protein decreased with MK‑677 compared with controls.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    DecreasePituitary SSTR-2 protein
    Study

    ratn: not reported in source

    Rats
    Comparator
    Control group
    Outcome group
    Growth hormone and IGF-1 · Endocrine and hormones
    Studied dose
    4 mg/kg · oral · 6 weeksAs given in this study (rat).

    Source sentences

    Summary
    Protein expression of hypothalamic GHSR, SST, and pituitary SSTR-2 showed patterns similar to those for mRNA expression.
    2 context sentences
    Summary · context
    Somatostatin (SST) mRNA expression in the hypothalamus was markedly increased in the treatment group, whereas SST receptor (SSTR)-2 mRNA expression in the pituitary gland was decreased.
    Summary · context
    Body weight, body length, tibia length, epiphyseal plate width, and serum levels of insulin-like growth factor (IGF)-I were measured after oral administration of 4 mg/kg of MK-677 for 6 weeks to investigate growth-promoting effects.

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

    14 Oct 2026, 05:02 UTC

    Study results updated

  2. Version 1

    14 Oct 2026, 01:46 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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