Repeat administration of the GH secretagogue MK-0677 increases and maintains elevated IGF-I levels in beagles.

Hickey GJ, Jacks TM, Schleim KD, Frazier E, Chen HY, Krupa D, Feeney W, Nargund RP, Patchett AA, Smith RG

The Journal of endocrinology1 Feb 1997Cited by 29 (Europe PMC)

PMID9071975DOI10.1677/joe.0.1520183PepBankPUB-09071975

Publisher page PubMedAsk about this study

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 study17

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

01AnimalAnimal study (in vivo)Efficacy outcome
In beagles, initial MK-0677 administration increased GH secretion 7.9- to 9.8-fold.
In plain wordsIn beagles, initial MK-0677 administration increased growth hormone secretion 7.9- to 9.8-fold.
Peptide
MK-677 (ibutamoren)
Outcome
IncreaseInitial GH secretion at high dose
Study
dogn: not reported in source
Beagles
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1.0 mg/kg · oralAs given in this study (dog).
Source sentences
Summary
Following the initial oral administration of MK-0677, GH secretion (area under the time-response curve (AUC) ng/ml per h) was increased 7.9- to 9.8-fold (1.0 mg/kg), 5.6-fold (0.5 mg/kg) or 3.9-fold (0.25 mg/kg).
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
Report a problemFND-0907197501
02AnimalAnimal study (in vivo)Efficacy outcome
In beagles, initial MK-0677 administration increased GH secretion 5.6-fold.
In plain wordsIn beagles, initial MK-0677 administration increased growth hormone secretion 5.6-fold.
Peptide
MK-677 (ibutamoren)
Outcome
IncreaseInitial GH secretion at middle dose
Study
dogn: not reported in source
Beagles
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
0.5 mg/kg · oralAs given in this study (dog).
Source sentences
Summary
Following the initial oral administration of MK-0677, GH secretion (area under the time-response curve (AUC) ng/ml per h) was increased 7.9- to 9.8-fold (1.0 mg/kg), 5.6-fold (0.5 mg/kg) or 3.9-fold (0.25 mg/kg).
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
Report a problemFND-0907197502
03AnimalAnimal study (in vivo)Efficacy outcome
In beagles, initial MK-0677 administration increased GH secretion 3.9-fold.
In plain wordsIn beagles, initial MK-0677 administration increased growth hormone secretion 3.9-fold.
Peptide
MK-677 (ibutamoren)
Outcome
IncreaseInitial GH secretion at low dose
Study
dogn: not reported in source
Beagles
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
0.25 mg/kg · oralAs given in this study (dog).
Source sentences
Summary
Following the initial oral administration of MK-0677, GH secretion (area under the time-response curve (AUC) ng/ml per h) was increased 7.9- to 9.8-fold (1.0 mg/kg), 5.6-fold (0.5 mg/kg) or 3.9-fold (0.25 mg/kg).
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
Report a problemFND-0907197503
04AnimalAnimal study (in vivo)Efficacy outcome
In beagles, repeat MK-0677 administration decreased the GH response by 41-77%.
In plain wordsIn beagles, repeat MK-0677 administration decreased the growth hormone response compared with initial administration.
Peptide
MK-677 (ibutamoren)
Outcome
DecreaseGH response with repeat administration
Study
dogn: not reported in source
Beagles
Comparator
Initial administration
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated · oralAs given in this study (dog).
Source sentences
Summary
With repeat MK-0677 administration, the GH response was decreased by 41-77%; GH concentrations remained significantly above control in the 0.5 mg/kg and 1.0 mg/kg groups.
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
Report a problemFND-0907197504
05AnimalAnimal study (in vivo)Efficacy outcome
In beagles, GH remained significantly above control during repeat MK-0677 administration at 0.5 mg/kg.
In plain wordsIn beagles, growth hormone remained significantly above control during repeat MK-0677 administration.
Peptide
MK-677 (ibutamoren)
Outcome
IncreaseSustained GH concentration at middle dose
Study
dogn: not reported in source
Beagles
Comparator
Control
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
0.5 mg/kg · oralAs given in this study (dog).
Source sentences
Summary
With repeat MK-0677 administration, the GH response was decreased by 41-77%; GH concentrations remained significantly above control in the 0.5 mg/kg and 1.0 mg/kg groups.
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
Report a problemFND-0907197505
06AnimalAnimal study (in vivo)Efficacy outcome
In beagles, GH remained significantly above control during repeat MK-0677 administration at 1.0 mg/kg.
In plain wordsIn beagles, growth hormone remained significantly above control during repeat MK-0677 administration.
Peptide
MK-677 (ibutamoren)
Outcome
IncreaseSustained GH concentration at high dose
Study
dogn: not reported in source
Beagles
Comparator
Control
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1.0 mg/kg · oralAs given in this study (dog).
Source sentences
Summary
With repeat MK-0677 administration, the GH response was decreased by 41-77%; GH concentrations remained significantly above control in the 0.5 mg/kg and 1.0 mg/kg groups.
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
Report a problemFND-0907197506
07AnimalAnimal study (in vivo)Mechanism
In beagles, increased GH after MK-0677 was associated with an amplified pulsatile profile.
In plain wordsIn beagles, increased growth hormone after MK-0677 was linked to an amplified pulsatile profile.
Peptide
MK-677 (ibutamoren)
Outcome
IncreaseGH pulsatile profile
Study
dogn: not reported in source
Beagles
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated · oralAs given in this study (dog).
Source sentences
Summary
Individual beagle GH profiles indicated that the increased GH concentration was associated with an amplified GH pulsatile profile.
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
Report a problemFND-0907197507
08AnimalAnimal study (in vivo)Efficacy outcome
In beagles, MK-0677 significantly increased IGF-I over control at all dosage levels on the first day.
In plain wordsIn beagles, MK-0677 significantly increased IGF-I over control at all dosage levels on the first day.
Peptide
MK-677 (ibutamoren)
Outcome
IncreaseInitial IGF-I levels
Study
dogn: not reported in source
Beagles
Comparator
Control
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated · oralAs given in this study (dog).
Source sentences
Summary
Serum IGF-I levels were significantly increased over control levels at all dosage levels by 480 min on the first day of MK-0677 administration.
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
Report a problemFND-0907197508
09AnimalAnimal study (in vivo)Efficacy outcome
In beagles, repeated MK-0677 increased IGF-I up to 126% and maintained elevation through 14 days.
In plain wordsIn beagles, repeated MK-0677 increased IGF-I and maintained elevation through 14 days.
Peptide
MK-677 (ibutamoren)
Outcome
IncreaseSustained IGF-I levels
Study
dogn: not reported in source
Beagles
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated · oral · 14 daysAs given in this study (dog).
Source sentences
Summary
With repeated administration, IGF-I levels were increased up to 126% and remained elevated through 14 days, the longest treatment period evaluated.
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
Report a problemFND-0907197509
10AnimalAnimal study (in vivo)Efficacy outcome
In beagles, daily MK-0677 significantly increased pretreatment IGF-I on days 4-14.
In plain wordsIn beagles, daily MK-0677 significantly increased pretreatment IGF-I.
Peptide
MK-677 (ibutamoren)
Outcome
IncreasePretreatment IGF-I with daily dosing
Study
dogn: not reported in source
Beagles
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated · oralAs given in this study (dog).
Source sentences
Summary
While daily MK-0677 administration appeared to increase IGF-I levels over 24 h, as evidenced by significant increases in the pretreatment IGF-I levels on days 4-14, no such increase was noted with alternate day MK-0677 administration; thus the dosage regimen modulated circulating IGF-I levels.
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
Report a problemFND-0907197510
11AnimalAnimal study (in vivo)Efficacy outcome
In beagles, alternate-day MK-0677 did not increase pretreatment IGF-I as daily treatment did.
In plain wordsIn beagles, alternate-day MK-0677 did not increase pretreatment IGF-I as daily treatment did.
Peptide
MK-677 (ibutamoren)
Outcome
No significant changePretreatment IGF-I with alternate-day dosing
Study
dogn: not reported in source
Beagles
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated · oralAs given in this study (dog).
Source sentences
Summary
While daily MK-0677 administration appeared to increase IGF-I levels over 24 h, as evidenced by significant increases in the pretreatment IGF-I levels on days 4-14, no such increase was noted with alternate day MK-0677 administration; thus the dosage regimen modulated circulating IGF-I levels.
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
Report a problemFND-0907197511
12AnimalAnimal study (in vivo)Efficacy outcome
In beagles, MK-0677 increased cortisol secretion on the first treatment day.
In plain wordsIn beagles, MK-0677 increased cortisol secretion on the first treatment day.
Peptide
MK-677 (ibutamoren)
Outcome
IncreaseInitial cortisol secretion
Study
dogn: not reported in source
Beagles
Outcome group
Stress hormones · Endocrine and hormones
Studied dose
Dose not stated · oralAs given in this study (dog).
Source sentences
Summary
MK-0677 stimulated increases in cortisol secretion (AUC microgram/dl per h) on the first day of treatment.
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
Report a problemFND-0907197512
13AnimalAnimal study (in vivo)Efficacy outcome
In beagles, the cortisol response decreased during repeated daily MK-0677 treatment.
In plain wordsIn beagles, the cortisol response decreased during repeated daily MK-0677 treatment compared with initial administration.
Peptide
MK-677 (ibutamoren)
Outcome
DecreaseCortisol response with repeated daily dosing
Study
dogn: not reported in source
Beagles
Comparator
Initial administration
Outcome group
Stress hormones · Endocrine and hormones
Studied dose
Dose not stated · oralAs given in this study (dog).
Source sentences
Summary
A decreased cortisol response was observed following repeated daily treatment with MK-0677; in contrast, with alternate day treatment, no decrease in cortisol response to MK-0677 occurred.
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
Report a problemFND-0907197513
14AnimalAnimal study (in vivo)Efficacy outcome
In beagles, the cortisol response did not decrease during alternate-day MK-0677 treatment.
In plain wordsIn beagles, the cortisol response did not decrease during alternate-day MK-0677 treatment.
Peptide
MK-677 (ibutamoren)
Outcome
No significant changeCortisol response with alternate-day dosing
Study
dogn: not reported in source
Beagles
Outcome group
Stress hormones · Endocrine and hormones
Studied dose
Dose not stated · oralAs given in this study (dog).
Source sentences
Summary
A decreased cortisol response was observed following repeated daily treatment with MK-0677; in contrast, with alternate day treatment, no decrease in cortisol response to MK-0677 occurred.
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
Report a problemFND-0907197514

Studies that did not test the peptide alone3

In this study, MK-677 (ibutamoren) was a lab tool or a carrier, part of a mix, or the subject of a lab method. These results are not evidence about taking MK-677 (ibutamoren).

15AnimalNot a test of MK-677 (ibutamoren) aloneAnimal study (in vivo)Mechanism
In beagles, exogenous GH increased IGF-I and decreased the GH response to MK-0677 compared with control animals.
In plain wordsIn beagles, exogenous growth hormone decreased the growth hormone response to MK-0677 compared with control animals.
Peptide
MK-677 (ibutamoren)
Outcome
DecreaseGH response after exogenous GH
Study
dogn: not reported in source
Beagles
Comparator
Control animals
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
A marked increase in circulating IGF-I concentrations following administration of exogenous GH resulted in a significant decrease in both the GH and cortisol response to MK-0677 compared with control animals.
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
In this study, MK-677 (ibutamoren) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking MK-677 (ibutamoren).
Report a problemFND-0907197515
16AnimalNot a test of MK-677 (ibutamoren) aloneAnimal study (in vivo)Mechanism
In beagles, exogenous GH increased IGF-I and decreased the cortisol response to MK-0677 compared with control animals.
In plain wordsIn beagles, exogenous growth hormone decreased the cortisol response to MK-0677 compared with control animals.
Peptide
MK-677 (ibutamoren)
Outcome
DecreaseCortisol response after exogenous GH
Study
dogn: not reported in source
Beagles
Comparator
Control animals
Outcome group
Stress hormones · Endocrine and hormones
Source sentences
Summary
A marked increase in circulating IGF-I concentrations following administration of exogenous GH resulted in a significant decrease in both the GH and cortisol response to MK-0677 compared with control animals.
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
In this study, MK-677 (ibutamoren) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking MK-677 (ibutamoren).
Report a problemFND-0907197516
17AnimalNot a test of MK-677 (ibutamoren) aloneAnimal study (in vivo)Mechanism
In beagles, exogenous GH markedly increased circulating IGF-I before testing the response to MK-0677.
In plain wordsIn beagles, exogenous growth hormone increased circulating IGF-I before the MK-0677 challenge.
Peptide
MK-677 (ibutamoren)
Outcome
IncreaseIGF-I after exogenous GH
Study
dogn: not reported in source
Beagles
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
A marked increase in circulating IGF-I concentrations following administration of exogenous GH resulted in a significant decrease in both the GH and cortisol response to MK-0677 compared with control animals.
1 context sentence(design, population, supporting numbers)
Summary · context
In the current study, we determined the effect of repeat oral administration of MK-0677 on GH, IGF-I and cortisol levels; we also investigated if the GH and cortisol responses to MK-0677 are influenced by circulating IGF-I concentrations.
In this study, MK-677 (ibutamoren) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking MK-677 (ibutamoren).
Report a problemFND-0907197517

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.

Version 2Current
14 Oct 2026, 05:02 UTC
Study results updated
Version 1
14 Oct 2026, 01:46 UTC
First added · source update from Europe PMC

Subjects

Terms as the source lists them.

Publication types

Journal Article

MeSH terms

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