Secretory mechanisms of growth hormone (GH)-releasing peptide-, GH-releasing hormone-, and thyrotropin-releasing hormone-induced GH release in patients with acromegaly.

Hanew K, Utsumi A, Tanaka A, Ikeda H, Yokogoshi Y

The Journal of clinical endocrinology and metabolism1 Oct 1998Cited by 4 (Europe PMC)

PMID9768668DOI10.1210/jcem.83.10.5171PepBankPUB-09768668

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

3 results from studies that gave the peptide. 1 result from people.

01HumanNon-randomized trialActivity measurement
In patients with acromegaly, GHRP induced clear GH responses in all four patients tested.
In plain wordsIn patients with acromegaly, GHRP increased growth hormone in all four patients tested.
Peptide
GHRP-6
Outcome
IncreaseGH response in vivo
Study
n = 4
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated
Measurements
Patients with clear GH response
4 patients
in vivo, single administration of GHRP, four of four patients tested
Source sentences
Summary
In an in vivo study, these patients showed clear GH responses to single administration of GHRP (four of four patients), GHRH (seven of seven patients), and TRH (seven of seven patients) and enhanced responses to GHRP plus GHRH (two of four patients) or TRH plus GHRH (six of six patients).
1 context sentence(design, population, supporting numbers)
Summary · context
The GH secretory mechanism of GH-releasing hexapeptide (GHRP-6), GHRH, and TRH were studied in vivo and in vitro in seven patients with acromegaly.
Report a problemFND-0976866801
02LabIn vitro (cells)Activity measurement
In dispersed acromegaly tumor cells, GHRP induced clear GH responses in samples from four of four patients.
In plain wordsIn cells from acromegaly tumors, GHRP increased growth hormone release in all four samples.
Peptide
GHRP-6
Outcome
IncreaseGH response in vitro
Study
humann = 4
Dispersed somatotropinoma cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
In an in vitro dispersed cell study, the majority of patients examined also showed clear GH responses to GHRP (four of four patients), GHRH (six of six patients), and TRH (four of four patients) and an enhanced response to GHRP plus GHRH (three of three patients) or TRH plus GHRH (three of four patients).
1 context sentence(design, population, supporting numbers)
Summary · context
The GH secretory mechanism of GH-releasing hexapeptide (GHRP-6), GHRH, and TRH were studied in vivo and in vitro in seven patients with acromegaly.
Report a problemFND-0976866803
03LabIn vitro (cells)Mechanism
In one acromegaly tumor sample, GHRP alone did not modify intracellular cAMP.
In plain wordsIn cells from one tumor, GHRP alone did not change internal cAMP.
Peptide
GHRP-6
Outcome
No significant changecAMP after GHRP alone
Study
humann = 1
Dispersed somatotropinoma cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
In contrast, NDGA distinctly elevated intracellular cAMP levels in another patient (no. 7) when coadministered with GHRP, GHRH, or GHRP plus GHRH, whereas cAMP levels were not modified by single administration of GHRP and NDGA.
1 context sentence(design, population, supporting numbers)
Summary · context
The GH secretory mechanism of GH-releasing hexapeptide (GHRP-6), GHRH, and TRH were studied in vivo and in vitro in seven patients with acromegaly.
Report a problemFND-0976866811

Studies that did not test the peptide alone10

In this study, GHRP-6 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 GHRP-6.

04HumanNot a test of GHRP-6 aloneNon-randomized trialActivity measurement
In patients with acromegaly, GH responses to GHRP plus GHRH were enhanced in two of four patients.
In plain wordsIn patients with acromegaly, growth hormone responses to GHRP plus GHRH were enhanced in two of four patients.
Peptide
GHRP-6
Outcome
IncreaseGH response with GHRH in vivo
Study
n = 4
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Measurements
Patients with enhanced GH response
2 patients
in vivo, GHRP plus GHRH, two of four patients tested
Source sentences
Summary
In an in vivo study, these patients showed clear GH responses to single administration of GHRP (four of four patients), GHRH (seven of seven patients), and TRH (seven of seven patients) and enhanced responses to GHRP plus GHRH (two of four patients) or TRH plus GHRH (six of six patients).
1 context sentence(design, population, supporting numbers)
Summary · context
The GH secretory mechanism of GH-releasing hexapeptide (GHRP-6), GHRH, and TRH were studied in vivo and in vitro in seven patients with acromegaly.
In this study, GHRP-6 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 GHRP-6.
Report a problemFND-0976866802
05LabNot a test of GHRP-6 aloneIn vitro (cells)Activity measurement
In acromegaly tumor cells, adding GHRP to GHRH enhanced GH responses in three of three patient samples.
In plain wordsIn cells from acromegaly tumors, GHRP plus GHRH enhanced growth hormone release in all three patient samples.
Peptide
GHRP-6
Outcome
IncreaseGH response with GHRH in vitro
Study
humann = 3
Dispersed somatotropinoma cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
In an in vitro dispersed cell study, the majority of patients examined also showed clear GH responses to GHRP (four of four patients), GHRH (six of six patients), and TRH (four of four patients) and an enhanced response to GHRP plus GHRH (three of three patients) or TRH plus GHRH (three of four patients).
1 context sentence(design, population, supporting numbers)
Summary · context
The GH secretory mechanism of GH-releasing hexapeptide (GHRP-6), GHRH, and TRH were studied in vivo and in vitro in seven patients with acromegaly.
In this study, GHRP-6 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 GHRP-6.
Report a problemFND-0976866804
06LabNot a test of GHRP-6 aloneIn vitro (cells)Activity measurement
In two other acromegaly tumor samples, GHRP plus GHRH produced additive GH responses.
In plain wordsIn cells from two other tumors, GHRP plus GHRH produced additive growth hormone responses.
Peptide
GHRP-6
Outcome
IncreaseAdditive GH response
Study
humann = 2
Dispersed somatotropinoma cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
The GH response to the combined administration of GHRP and GHRH was synergistic in this patient, but was additive in the other two patients.
1 context sentence(design, population, supporting numbers)
Summary · context
The GH secretory mechanism of GH-releasing hexapeptide (GHRP-6), GHRH, and TRH were studied in vivo and in vitro in seven patients with acromegaly.
In this study, GHRP-6 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 GHRP-6.
Report a problemFND-0976866813
07LabNot a test of GHRP-6 aloneIn vitro (cells)Activity measurement
In one acromegaly tumor sample, GHRP plus forskolin additively enhanced GH release.
In plain wordsIn cells from one tumor, GHRP plus forskolin additively increased growth hormone release.
Peptide
GHRP-6
Outcome
IncreaseGH response with forskolin
Study
humann = 1
Dispersed somatotropinoma cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
In one patient (no. 3), GHRP plus forskolin (adenylate cyclase activator), but not GHRP plus phorbol 12-myristate 13-acetate (protein kinase C activator), additively enhanced the GH response.
1 context sentence(design, population, supporting numbers)
Summary · context
The GH secretory mechanism of GH-releasing hexapeptide (GHRP-6), GHRH, and TRH were studied in vivo and in vitro in seven patients with acromegaly.
In this study, GHRP-6 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 GHRP-6.
Report a problemFND-0976866805
08LabNot a test of GHRP-6 aloneIn vitro (cells)Activity measurement
In one acromegaly tumor sample, GHRP plus phorbol ester did not additively enhance GH release.
In plain wordsIn cells from one tumor, GHRP plus phorbol ester did not additively increase growth hormone release.
Peptide
GHRP-6
Outcome
No significant changeGH response with phorbol ester
Study
humann = 1
Dispersed somatotropinoma cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
In one patient (no. 3), GHRP plus forskolin (adenylate cyclase activator), but not GHRP plus phorbol 12-myristate 13-acetate (protein kinase C activator), additively enhanced the GH response.
1 context sentence(design, population, supporting numbers)
Summary · context
The GH secretory mechanism of GH-releasing hexapeptide (GHRP-6), GHRH, and TRH were studied in vivo and in vitro in seven patients with acromegaly.
In this study, GHRP-6 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 GHRP-6.
Report a problemFND-0976866806
09LabNot a test of GHRP-6 aloneIn vitro (cells)Mechanism
In one acromegaly tumor sample, NDGA coadministered with GHRP elevated intracellular cAMP.
In plain wordsIn cells from one tumor, NDGA with GHRP raised internal cAMP.
Peptide
GHRP-6
Outcome
IncreasecAMP with NDGA and GHRP
Study
humann = 1
Dispersed somatotropinoma cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
In contrast, NDGA distinctly elevated intracellular cAMP levels in another patient (no. 7) when coadministered with GHRP, GHRH, or GHRP plus GHRH, whereas cAMP levels were not modified by single administration of GHRP and NDGA.
1 context sentence(design, population, supporting numbers)
Summary · context
The GH secretory mechanism of GH-releasing hexapeptide (GHRP-6), GHRH, and TRH were studied in vivo and in vitro in seven patients with acromegaly.
In this study, GHRP-6 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 GHRP-6.
Report a problemFND-0976866809
10LabNot a test of GHRP-6 aloneIn vitro (cells)Mechanism
In one acromegaly tumor sample, NDGA with GHRP plus GHRH elevated intracellular cAMP.
In plain wordsIn cells from one tumor, NDGA with GHRP plus GHRH raised internal cAMP.
Peptide
GHRP-6
Outcome
IncreasecAMP with NDGA and GHRP plus GHRH
Study
humann = 1
Dispersed somatotropinoma cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
In contrast, NDGA distinctly elevated intracellular cAMP levels in another patient (no. 7) when coadministered with GHRP, GHRH, or GHRP plus GHRH, whereas cAMP levels were not modified by single administration of GHRP and NDGA.
1 context sentence(design, population, supporting numbers)
Summary · context
The GH secretory mechanism of GH-releasing hexapeptide (GHRP-6), GHRH, and TRH were studied in vivo and in vitro in seven patients with acromegaly.
In this study, GHRP-6 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 GHRP-6.
Report a problemFND-0976866810
11LabNot a test of GHRP-6 aloneIn vitro (cells)Activity measurement
In one acromegaly tumor sample, GHRP plus GHRH produced a synergistic GH response.
In plain wordsIn cells from one tumor, GHRP plus GHRH produced a synergistic growth hormone response.
Peptide
GHRP-6
Outcome
IncreaseSynergistic GH response
Study
humann = 1
Dispersed somatotropinoma cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
The GH response to the combined administration of GHRP and GHRH was synergistic in this patient, but was additive in the other two patients.
1 context sentence(design, population, supporting numbers)
Summary · context
The GH secretory mechanism of GH-releasing hexapeptide (GHRP-6), GHRH, and TRH were studied in vivo and in vitro in seven patients with acromegaly.
In this study, GHRP-6 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 GHRP-6.
Report a problemFND-0976866812
12LabNot a test of GHRP-6 aloneIn vitro (cells)Activity measurement
In acromegaly tumor cells, NDGA inhibited GHRP-induced GH release.
In plain wordsIn tumor cells, NDGA reduced growth hormone release induced by GHRP.
Peptide
GHRP-6
Outcome
DecreaseNDGA inhibition of GHRP-induced GH release
Study
humann: not reported in source
Dispersed somatotropinoma cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
Nordihydroguaiaretic acid (NDGA; inhibitor of arachidonic cascade) inhibited GH release induced by GHRP, TRH, GHRH, TRH plus GHRH, or GHRP plus GHRH, but did not inhibit basal GH secretion.
1 context sentence(design, population, supporting numbers)
Summary · context
The GH secretory mechanism of GH-releasing hexapeptide (GHRP-6), GHRH, and TRH were studied in vivo and in vitro in seven patients with acromegaly.
In this study, GHRP-6 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 GHRP-6.
Report a problemFND-0976866807
13LabNot a test of GHRP-6 aloneIn vitro (cells)Activity measurement
In acromegaly tumor cells, NDGA inhibited GH release induced by GHRP plus GHRH.
In plain wordsIn tumor cells, NDGA reduced growth hormone release induced by GHRP plus GHRH.
Peptide
GHRP-6
Outcome
DecreaseNDGA inhibition of combination-induced GH release
Study
humann: not reported in source
Dispersed somatotropinoma cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
Nordihydroguaiaretic acid (NDGA; inhibitor of arachidonic cascade) inhibited GH release induced by GHRP, TRH, GHRH, TRH plus GHRH, or GHRP plus GHRH, but did not inhibit basal GH secretion.
1 context sentence(design, population, supporting numbers)
Summary · context
The GH secretory mechanism of GH-releasing hexapeptide (GHRP-6), GHRH, and TRH were studied in vivo and in vitro in seven patients with acromegaly.
In this study, GHRP-6 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 GHRP-6.
Report a problemFND-0976866808

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
21 Oct 2026, 15:58 UTC
Study results updated
Version 1
9 Oct 2026, 03:13 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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