Desensitization studies using perifused rat pituitary cells show that growth hormone-releasing hormone and His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 stimulate growth hormone release through distinct receptor sites.

Blake AD, Smith RG

The Journal of endocrinology1 Apr 1991Cited by 75 (Europe PMC)

PMID1674284DOI10.1677/joe.0.1290011PepBankPUB-01674284

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 study7

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

01LabIn vitro (cells)Mechanism
In rat pituitary cells, GHRP‑6 rapidly released GH.
In plain wordsIn cells from rats, GHRP‑6 rapidly increased GH release.
Peptide
GHRP-6
Outcome
IncreaseGH release
Study
ratn: not reported in source
dispersed pituitary cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
The hexapeptide His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 (GHRP-6) and GH-releasing factor (GHRH) produced a rapid release of GH upon perifusion of dispersed rat pituitary cells.
Report a problemFND-0167428401
02LabIn vitro (cells)Mechanism
In rat pituitary cells, GHRP‑6 elicited a shorter GH response than GHRH.
In plain wordsIn cells from rats, GHRP‑6 produced a shorter GH response than GHRH.
Peptide
GHRP-6
Outcome
DecreaseResponse duration
Study
ratn: not reported in source
dispersed pituitary cells
Comparator
GHRH
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
In contrast to the native hormone GHRH, GHRP-6 elicited a response of short duration.
1 context sentence(design, population, supporting numbers)
Summary · context
The hexapeptide His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 (GHRP-6) and GH-releasing factor (GHRH) produced a rapid release of GH upon perifusion of dispersed rat pituitary cells.
Report a problemFND-0167428402
03LabIn vitro (cells)Mechanism
In rat pituitary cells desensitized to GHRH, GHRP‑6 immediately produced secondary GH release.
In plain wordsIn cells from rats that stopped responding to GHRH, GHRP‑6 still released GH.
Peptide
GHRP-6
Outcome
IncreaseCross-desensitization
Study
ratn: not reported in source
dispersed pituitary cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
When perifusion of each secretagogue was continued until the cells no longer released GH, a challenge by the alternative secretagogue immediately resulted in a secondary release of GH.
1 context sentence(design, population, supporting numbers)
Summary · context
The hexapeptide His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 (GHRP-6) and GH-releasing factor (GHRH) produced a rapid release of GH upon perifusion of dispersed rat pituitary cells.
Report a problemFND-0167428403
04LabIn vitro (cells)Mechanism
Rat pituitary cells required 60 min of medium perifusion to regain full responsiveness after a 1 min GHRP‑6 exposure.
In plain wordsIn cells from rats, responsiveness recovered after GHRP‑6 removal.
Peptide
GHRP-6
Outcome
Not applicableRecovery of responsiveness
Study
ratn: not reported in source
dispersed pituitary cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated · 1 minAs given in this study (rat).
Source sentences
Summary
Cells which were perifused for 1 min with GHRP-6 required continued perifusion with culture medium alone for 60 min before they completely regained responsiveness to a subsequent challenge with GHRP-6.
Report a problemFND-0167428404

Studies that did not test the peptide alone3

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.

05LabNot a test of GHRP-6 aloneIn vitro (cells)Mechanism
In rat pituitary cells, somatostatin completely inhibited GHRP‑6-stimulated GH release.
In plain wordsIn cells from rats, somatostatin completely blocked GH release stimulated by GHRP‑6.
Peptide
GHRP-6
Outcome
DecreaseSomatostatin inhibition
Study
ratn: not reported in source
dispersed pituitary cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
Somatostatin (SRIF) was able to inhibit the action of either secretagogue completely.
1 context sentence(design, population, supporting numbers)
Summary · context
The hexapeptide His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 (GHRP-6) and GH-releasing factor (GHRH) produced a rapid release of GH upon perifusion of dispersed rat pituitary cells.
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-0167428405
06LabNot a test of GHRP-6 aloneIn vitro (cells)Mechanism
In rat pituitary cells, somatostatin attenuated but did not block GH release with GHRH plus GHRP‑6.
In plain wordsIn cells from rats, somatostatin partly inhibited GH release stimulated by GHRH plus GHRP‑6.
Peptide
GHRP-6
Outcome
DecreaseSomatostatin inhibition of combined stimulation
Study
ratn: not reported in source
dispersed pituitary cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
However, when both GHRH and GHRP-6 were perifused together, SRIF attenuated but did not block GH secretion.
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-0167428406
07LabNot a test of GHRP-6 aloneIn vitro (cells)Mechanism
In rat pituitary cells desensitized to GHRP‑6, GHRH immediately induced another GH release.
In plain wordsIn cells from rats that stopped responding to GHRP‑6, GHRH still released GH.
Peptide
GHRP-6
Outcome
IncreaseGHRH response after GHRP-6 desensitization
Study
ratn: not reported in source
dispersed rat pituitary cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
When perifusion of each secretagogue was continued until the cells no longer released GH, a challenge by the alternative secretagogue immediately resulted in a secondary release of GH.
1 context sentence(design, population, supporting numbers)
Summary · context
The hexapeptide His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 (GHRP-6) and GH-releasing factor (GHRH) produced a rapid release of GH upon perifusion of dispersed rat pituitary cells.
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-0167428407

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, 15:59 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.

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Journal Article

MeSH terms

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