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Study · In vitro (cell-free) · 2009

10 results

Growth hormone secretagogues and growth hormone releasing peptides act as orthosteric super-agonists but not allosteric regulators for activation of the G protein Galpha(o1) by the Ghrelin receptor.

Bennett KA, Langmead CJ, Wise A, Milligan G

Molecular pharmacology22 Jul 2009Cited by 30 (Europe PMC)

PMID19625579 (opens in a new tab)PMCIDPMC2769045 (opens in a new tab)DOI10.1124/mol.109.056101 (opens in a new tab)PepBankPUB-19625579
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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: Publisher copyright. Results still quote short attributed sentences.

Results from this study10

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

  1. 01LabIn vitro (cell-free)Mechanism

    In receptor-bearing cell membranes, GHRP‑6 functioned as a direct agonist.

    In plain wordsIn lab tests, GHRP‑6 directly activated the ghrelin receptor.

    Peptide
    GHRP-6
    Outcome
    IncreaseDirect receptor agonism
    Study

    n: not reported in source

    membranes from cells coexpressing human ghrelin receptor and Galpha(o1)
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Source sentences

    Summary
    each functioned as direct agonists, and each displayed higher efficacy than ghrelin.
    1 context sentence
    Summary · context
    In membranes prepared from cells coexpressing the human ghrelin receptor and the G protein Galpha(o1),
  2. 02LabIn vitro (cell-free)Mechanism

    In receptor-bearing cell membranes, MK‑677 functioned as a direct agonist.

    In plain wordsIn lab tests, MK‑677 directly activated the ghrelin receptor.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    IncreaseDirect receptor agonism
    Study

    n: not reported in source

    membranes from cells coexpressing human ghrelin receptor and Galpha(o1)
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Source sentences

    Summary
    each functioned as direct agonists, and each displayed higher efficacy than ghrelin.
    1 context sentence
    Summary · context
    In membranes prepared from cells coexpressing the human ghrelin receptor and the G protein Galpha(o1),
  3. 03LabIn vitro (cell-free)Mechanism

    In receptor-bearing cell membranes, GHRP‑6 displayed higher agonist efficacy than ghrelin.

    In plain wordsIn lab tests, GHRP‑6 activated the receptor more strongly than ghrelin.

    Peptide
    GHRP-6
    Outcome
    IncreaseReceptor agonist efficacy
    Study

    n: not reported in source

    membranes from cells coexpressing human ghrelin receptor and Galpha(o1)
    Comparator
    Ghrelin
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Source sentences

    Summary
    each functioned as direct agonists, and each displayed higher efficacy than ghrelin.
    1 context sentence
    Summary · context
    In membranes prepared from cells coexpressing the human ghrelin receptor and the G protein Galpha(o1),
  4. 04LabIn vitro (cell-free)Mechanism

    In receptor-bearing cell membranes, MK‑677 displayed higher agonist efficacy than ghrelin.

    In plain wordsIn lab tests, MK‑677 activated the receptor more strongly than ghrelin.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    IncreaseReceptor agonist efficacy
    Study

    n: not reported in source

    membranes from cells coexpressing human ghrelin receptor and Galpha(o1)
    Comparator
    Ghrelin
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Source sentences

    Summary
    each functioned as direct agonists, and each displayed higher efficacy than ghrelin.
    1 context sentence
    Summary · context
    In membranes prepared from cells coexpressing the human ghrelin receptor and the G protein Galpha(o1),
  5. 05LabIn vitro (cell-free)Mechanism

    In analysis of GHRP‑6 receptor data, simple competition between partial and full agonists gave the best model fit.

    In plain wordsIn lab tests, GHRP‑6 receptor data best matched simple competition between partial and full agonists.

    Peptide
    GHRP-6
    Outcome
    Not applicableCompetition model fit
    Study

    n: not reported in source

    membranes from cells coexpressing human ghrelin receptor and Galpha(o1)
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Source sentences

    Summary
    Each of the data sets was best fit by a model of simple competition between a partial and a full agonist.
    1 context sentence
    Summary · context
    was analyzed globally according to a modified version of an operational model of allosterism that accounts for allosteric modulation of affinity, efficacy, and allosteric agonism.
  6. 06LabIn vitro (cell-free)Mechanism

    In analysis of MK‑677 receptor data, simple competition between partial and full agonists gave the best model fit.

    In plain wordsIn lab tests, MK‑677 receptor data best matched simple competition between partial and full agonists.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    Not applicableCompetition model fit
    Study

    n: not reported in source

    membranes from cells coexpressing human ghrelin receptor and Galpha(o1)
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Source sentences

    Summary
    Each of the data sets was best fit by a model of simple competition between a partial and a full agonist.
    1 context sentence
    Summary · context
    was analyzed globally according to a modified version of an operational model of allosterism that accounts for allosteric modulation of affinity, efficacy, and allosteric agonism.
  7. 07LabIn vitro (cell-free)Mechanism

    In receptor assays, GHRP‑6 did not affect labeled ghrelin dissociation kinetics.

    In plain wordsIn lab tests, GHRP‑6 did not change how labeled ghrelin detached from the receptor.

    Peptide
    GHRP-6
    Outcome
    No significant changeGhrelin dissociation kinetics
    Study

    n: not reported in source

    membranes from cells coexpressing human ghrelin receptor and Galpha(o1)
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Source sentences

    Summary
    However, none of the proposed ago-allosteric regulators tested had any effect on the dissociation kinetics of (125)I-[His]-ghrelin,
  8. 08LabIn vitro (cell-free)Mechanism

    In receptor assays, MK‑677 did not affect labeled ghrelin dissociation kinetics.

    In plain wordsIn lab tests, MK‑677 did not change how labeled ghrelin detached from the receptor.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    No significant changeGhrelin dissociation kinetics
    Study

    n: not reported in source

    membranes from cells coexpressing human ghrelin receptor and Galpha(o1)
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Source sentences

    Summary
    However, none of the proposed ago-allosteric regulators tested had any effect on the dissociation kinetics of (125)I-[His]-ghrelin,
  9. 09LabIn vitro (cell-free)Mechanism

    In receptor assays, GHRP‑6 fully displaced labeled ghrelin from the receptor.

    In plain wordsIn lab tests, GHRP‑6 fully displaced labeled ghrelin from the receptor.

    Peptide
    GHRP-6
    Outcome
    IncreaseLabeled ghrelin displacement
    Study

    n: not reported in source

    membranes from cells coexpressing human ghrelin receptor and Galpha(o1)
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Source sentences

    Summary
    and GHRP-6 and MK-677 were able to fully displace (125)I-[His]-ghrelin from the receptor.
  10. 10LabIn vitro (cell-free)Mechanism

    In receptor assays, MK‑677 fully displaced labeled ghrelin from the receptor.

    In plain wordsIn lab tests, MK‑677 fully displaced labeled ghrelin from the receptor.

    Peptide
    MK-677 (ibutamoren)
    Outcome
    IncreaseLabeled ghrelin displacement
    Study

    n: not reported in source

    membranes from cells coexpressing human ghrelin receptor and Galpha(o1)
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Source sentences

    Summary
    and GHRP-6 and MK-677 were able to fully displace (125)I-[His]-ghrelin from the receptor.

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 3Current

    14 Oct 2026, 05:02 UTC

    Study results updated

  2. Version 2

    14 Oct 2026, 01:46 UTC

    Study data updated · source update from Europe PMC

  3. Version 1

    9 Oct 2026, 03:13 UTC

    First added · source update from Europe PMC

Subjects

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