Increases in circulating insulin-like growth factor I levels by the oral growth hormone secretagogue MK-0677 in the beagle are dependent upon pituitary mediation.

Schleim KD, Jacks T, Cunningham P, Feeney W, Frazier EG, Niebauer GW, Zhang D, Chen H, Smith RG, Hickey G

Endocrinology1 Apr 1999Cited by 21 (Europe PMC)

PMID10098487DOI10.1210/endo.140.4.6667PepBankPUB-10098487

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 study13

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

01AnimalAnimal study (in vivo)Efficacy outcome
In dogs before hypophysectomy, the mean peak GH increase after MK-0677 was 121.2 +/- 13.6 ng/ml.
In plain wordsIn dogs before pituitary removal, MK-0677 increased peak growth hormone from baseline.
Peptide
MK-677 (ibutamoren)
Outcome
IncreasePeak GH before hypophysectomy
Study
Dogn = 7
Dogs before hypophysectomy
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 mg/kg · oralAs given in this study (Dog).
Measurements
Peak GH increase
121.2 ng/ml
before hypophysectomy
Source sentences
Summary
The mean peak GH increases in response to MK-0677 in the presham dogs (83.7 +/- 19.2 ng/ml), post-sham dogs (108 +/- 26.2 ng/ml), and pre-hypox dogs (121.2 +/- 13.6 ng/ml) were not significantly different.
2 context sentences(design, population, supporting numbers)
Summary · context
Baseline GH, IGF-I, and cortisol responses to MK-0677 (1 mg/kg, orally) were initially determined.
Summary · context
Hypophysectomy (hypox; n = 7) or sham surgery (sham; n = 5) was then carried out.
Report a problemFND-1009848703
02AnimalAnimal study (in vivo)Efficacy outcome
In hypophysectomized dogs, peak GH remained unchanged after MK-0677 at 2.3 +/- 0.7 ng/ml.
In plain wordsIn dogs after pituitary removal, MK-0677 did not change peak growth hormone from baseline.
Peptide
MK-677 (ibutamoren)
Outcome
No significant changePeak GH after hypophysectomy
Study
Dogn = 7
Hypophysectomized dogs
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 mg/kg · oralAs given in this study (Dog).
Measurements
Peak GH
2.3 ng/ml
after hypophysectomy
Source sentences
Summary
Mean peak GH levels were unchanged after MK-0677 administration in the hypox dogs (2.3 +/- 0.7 ng/ml).
2 context sentences(design, population, supporting numbers)
Summary · context
Baseline GH, IGF-I, and cortisol responses to MK-0677 (1 mg/kg, orally) were initially determined.
Summary · context
Hypophysectomy (hypox; n = 7) or sham surgery (sham; n = 5) was then carried out.
Report a problemFND-1009848705
03AnimalAnimal study (in vivo)Efficacy outcome
In dogs before hypophysectomy, MK-0677 increased serum IGF-I to 224 +/- 47 ng/ml.
In plain wordsIn dogs before pituitary removal, MK-0677 increased serum IGF-I from baseline.
Peptide
MK-677 (ibutamoren)
Outcome
IncreaseIGF-I before hypophysectomy
Study
Dogn = 7
Dogs before hypophysectomy
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 mg/kg · oralAs given in this study (Dog).
Measurements
IGF-I
224 ng/ml
before hypophysectomy
Source sentences
Summary
Before surgery, serum IGF-I levels increased to 243 +/- 27 and 224 +/- 47 ng/ml in the sham and hypox groups, respectively, after MK-0677 administration.
2 context sentences(design, population, supporting numbers)
Summary · context
Baseline GH, IGF-I, and cortisol responses to MK-0677 (1 mg/kg, orally) were initially determined.
Summary · context
Hypophysectomy (hypox; n = 7) or sham surgery (sham; n = 5) was then carried out.
Report a problemFND-1009848707
04AnimalAnimal study (in vivo)Efficacy outcome
In hypophysectomized dogs, IGF-I remained unchanged after MK-0677 at 17.7 +/- 2.4 ng/ml.
In plain wordsIn dogs after pituitary removal, MK-0677 did not change serum IGF-I from baseline.
Peptide
MK-677 (ibutamoren)
Outcome
No significant changeIGF-I after hypophysectomy
Study
Dogn = 7
Hypophysectomized dogs
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 mg/kg · oralAs given in this study (Dog).
Measurements
IGF-I
17.7 ng/ml
hypophysectomized dogs
Source sentences
Summary
MK-0677 administration increased IGF-I levels in the sham dogs from 78 +/- 14 to 187 +/- 31 ng/ml, whereas IGF-I levels remained unchanged (17.7 +/- 2.4 ng/ml) in the-hypox dogs.
2 context sentences(design, population, supporting numbers)
Summary · context
Baseline GH, IGF-I, and cortisol responses to MK-0677 (1 mg/kg, orally) were initially determined.
Summary · context
Hypophysectomy (hypox; n = 7) or sham surgery (sham; n = 5) was then carried out.
Report a problemFND-1009848709
05AnimalAnimal study (in vivo)Efficacy outcome
In dogs before hypophysectomy, MK-0677 increased cortisol 3.6-fold.
In plain wordsIn dogs before pituitary removal, MK-0677 increased cortisol from baseline.
Peptide
MK-677 (ibutamoren)
Outcome
IncreaseCortisol before hypophysectomy
Study
Dogn = 7
Dogs before hypophysectomy
Outcome group
Stress hormones · Endocrine and hormones
Studied dose
1 mg/kg · oralAs given in this study (Dog).
Measurements
Cortisol increase
3.6 fold
pre-hypox
Source sentences
Summary
Cortisol was increased after MK-0677 administration 3.7-fold in the pre-sham, 3.6-fold in the post-sham, and 3.6-fold in the pre-hypox dogs, but no increase was seen in the post-hypox dogs.
2 context sentences(design, population, supporting numbers)
Summary · context
Baseline GH, IGF-I, and cortisol responses to MK-0677 (1 mg/kg, orally) were initially determined.
Summary · context
Hypophysectomy (hypox; n = 7) or sham surgery (sham; n = 5) was then carried out.
Report a problemFND-1009848712
06AnimalAnimal study (in vivo)Efficacy outcome
In hypophysectomized dogs, MK-0677 did not increase cortisol.
In plain wordsIn dogs after pituitary removal, MK-0677 did not increase cortisol from baseline.
Peptide
MK-677 (ibutamoren)
Outcome
No significant changeCortisol after hypophysectomy
Study
Dogn = 7
Hypophysectomized dogs
Outcome group
Stress hormones · Endocrine and hormones
Studied dose
1 mg/kg · oralAs given in this study (Dog).
Source sentences
Summary
Cortisol was increased after MK-0677 administration 3.7-fold in the pre-sham, 3.6-fold in the post-sham, and 3.6-fold in the pre-hypox dogs, but no increase was seen in the post-hypox dogs.
2 context sentences(design, population, supporting numbers)
Summary · context
Baseline GH, IGF-I, and cortisol responses to MK-0677 (1 mg/kg, orally) were initially determined.
Summary · context
Hypophysectomy (hypox; n = 7) or sham surgery (sham; n = 5) was then carried out.
Report a problemFND-1009848713
07AnimalAnimal study (in vivo)Efficacy outcome
In dogs before sham surgery, the mean peak GH increase after MK-0677 was 83.7 +/- 19.2 ng/ml.
In plain wordsIn dogs before sham surgery, MK-0677 increased peak growth hormone from baseline.
Peptide
MK-677 (ibutamoren)
Outcome
IncreasePeak GH before sham surgery
Study
Dogn = 5
Dogs before sham surgery
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 mg/kg · oralAs given in this study (Dog).
Measurements
Peak GH increase
83.7 ng/ml
before sham surgery
Source sentences
Summary
The mean peak GH increases in response to MK-0677 in the presham dogs (83.7 +/- 19.2 ng/ml), post-sham dogs (108 +/- 26.2 ng/ml), and pre-hypox dogs (121.2 +/- 13.6 ng/ml) were not significantly different.
2 context sentences(design, population, supporting numbers)
Summary · context
Baseline GH, IGF-I, and cortisol responses to MK-0677 (1 mg/kg, orally) were initially determined.
Summary · context
Hypophysectomy (hypox; n = 7) or sham surgery (sham; n = 5) was then carried out.
Report a problemFND-1009848701
08AnimalAnimal study (in vivo)Efficacy outcome
In dogs after sham surgery, the mean peak GH increase after MK-0677 was 108 +/- 26.2 ng/ml.
In plain wordsIn dogs after sham surgery, MK-0677 increased peak growth hormone from baseline.
Peptide
MK-677 (ibutamoren)
Outcome
IncreasePeak GH after sham surgery
Study
Dogn = 5
Dogs after sham surgery
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 mg/kg · oralAs given in this study (Dog).
Measurements
Peak GH increase
108 ng/ml
after sham surgery
Source sentences
Summary
The mean peak GH increases in response to MK-0677 in the presham dogs (83.7 +/- 19.2 ng/ml), post-sham dogs (108 +/- 26.2 ng/ml), and pre-hypox dogs (121.2 +/- 13.6 ng/ml) were not significantly different.
2 context sentences(design, population, supporting numbers)
Summary · context
Baseline GH, IGF-I, and cortisol responses to MK-0677 (1 mg/kg, orally) were initially determined.
Summary · context
Hypophysectomy (hypox; n = 7) or sham surgery (sham; n = 5) was then carried out.
Report a problemFND-1009848702
09AnimalAnimal study (in vivo)Efficacy outcome
In dogs before sham surgery, MK-0677 increased serum IGF-I to 243 +/- 27 ng/ml.
In plain wordsIn dogs before sham surgery, MK-0677 increased serum IGF-I from baseline.
Peptide
MK-677 (ibutamoren)
Outcome
IncreaseIGF-I before sham surgery
Study
Dogn = 5
Dogs before sham surgery
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 mg/kg · oralAs given in this study (Dog).
Measurements
IGF-I
243 ng/ml
before sham surgery
Source sentences
Summary
Before surgery, serum IGF-I levels increased to 243 +/- 27 and 224 +/- 47 ng/ml in the sham and hypox groups, respectively, after MK-0677 administration.
2 context sentences(design, population, supporting numbers)
Summary · context
Baseline GH, IGF-I, and cortisol responses to MK-0677 (1 mg/kg, orally) were initially determined.
Summary · context
Hypophysectomy (hypox; n = 7) or sham surgery (sham; n = 5) was then carried out.
Report a problemFND-1009848706
10AnimalAnimal study (in vivo)Efficacy outcome
In sham-operated dogs, MK-0677 increased serum IGF-I from 78 +/- 14 to 187 +/- 31 ng/ml.
In plain wordsIn sham-operated dogs, MK-0677 increased serum IGF-I from baseline.
Peptide
MK-677 (ibutamoren)
Outcome
IncreaseIGF-I after sham surgery
Study
Dogn = 5
Dogs after sham surgery
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 mg/kg · oralAs given in this study (Dog).
Measurements
IGF-I baseline
78 ng/ml
sham
IGF-I after treatment
187 ng/ml
sham
Source sentences
Summary
MK-0677 administration increased IGF-I levels in the sham dogs from 78 +/- 14 to 187 +/- 31 ng/ml, whereas IGF-I levels remained unchanged (17.7 +/- 2.4 ng/ml) in the-hypox dogs.
2 context sentences(design, population, supporting numbers)
Summary · context
Baseline GH, IGF-I, and cortisol responses to MK-0677 (1 mg/kg, orally) were initially determined.
Summary · context
Hypophysectomy (hypox; n = 7) or sham surgery (sham; n = 5) was then carried out.
Report a problemFND-1009848708
11AnimalAnimal study (in vivo)Efficacy outcome
In dogs before sham surgery, MK-0677 increased cortisol 3.7-fold.
In plain wordsIn dogs before sham surgery, MK-0677 increased cortisol from baseline.
Peptide
MK-677 (ibutamoren)
Outcome
IncreaseCortisol before sham surgery
Study
Dogn = 5
Dogs before sham surgery
Outcome group
Stress hormones · Endocrine and hormones
Studied dose
1 mg/kg · oralAs given in this study (Dog).
Measurements
Cortisol increase
3.7 fold
pre-sham
Source sentences
Summary
Cortisol was increased after MK-0677 administration 3.7-fold in the pre-sham, 3.6-fold in the post-sham, and 3.6-fold in the pre-hypox dogs, but no increase was seen in the post-hypox dogs.
2 context sentences(design, population, supporting numbers)
Summary · context
Baseline GH, IGF-I, and cortisol responses to MK-0677 (1 mg/kg, orally) were initially determined.
Summary · context
Hypophysectomy (hypox; n = 7) or sham surgery (sham; n = 5) was then carried out.
Report a problemFND-1009848710
12AnimalAnimal study (in vivo)Efficacy outcome
In dogs after sham surgery, MK-0677 increased cortisol 3.6-fold.
In plain wordsIn dogs after sham surgery, MK-0677 increased cortisol from baseline.
Peptide
MK-677 (ibutamoren)
Outcome
IncreaseCortisol after sham surgery
Study
Dogn = 5
Dogs after sham surgery
Outcome group
Stress hormones · Endocrine and hormones
Studied dose
1 mg/kg · oralAs given in this study (Dog).
Measurements
Cortisol increase
3.6 fold
post-sham
Source sentences
Summary
Cortisol was increased after MK-0677 administration 3.7-fold in the pre-sham, 3.6-fold in the post-sham, and 3.6-fold in the pre-hypox dogs, but no increase was seen in the post-hypox dogs.
2 context sentences(design, population, supporting numbers)
Summary · context
Baseline GH, IGF-I, and cortisol responses to MK-0677 (1 mg/kg, orally) were initially determined.
Summary · context
Hypophysectomy (hypox; n = 7) or sham surgery (sham; n = 5) was then carried out.
Report a problemFND-1009848711
13AnimalAnimal study (in vivo)Efficacy outcome
In dogs with an intact pituitary, peak GH increases after MK-0677 did not differ significantly across the reported groups.
In plain wordsIn dogs with an intact pituitary, MK-0677 growth hormone responses did not differ significantly across groups.
Peptide
MK-677 (ibutamoren)
Outcome
No significant changeGH response across intact-pituitary groups
Study
Dogn: not reported in source
Comparator
Pre-sham, post-sham and pre-hypox groups
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 mg/kg · oralAs given in this study (Dog).
Source sentences
Summary
The mean peak GH increases in response to MK-0677 in the presham dogs (83.7 +/- 19.2 ng/ml), post-sham dogs (108 +/- 26.2 ng/ml), and pre-hypox dogs (121.2 +/- 13.6 ng/ml) were not significantly different.
2 context sentences(design, population, supporting numbers)
Summary · context
Baseline GH, IGF-I, and cortisol responses to MK-0677 (1 mg/kg, orally) were initially determined.
Summary · context
Hypophysectomy (hypox; n = 7) or sham surgery (sham; n = 5) was then carried out.
Report a problemFND-1009848704

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

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