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Study · Animal study (in vivo) · rat · 2003

9 results

Ac-Nle-c[Asp-His-DPhe-Arg-Trp-Lys]-NH2 induces penile erection via brain and spinal melanocortin receptors.

Wessells H, Hruby VJ, Hackett J, Han G, Balse-Srinivasan P, Vanderah TW

Neuroscience1 Jan 2003Cited by 52 (Europe PMC)

PMID12710982 (opens in a new tab)DOI10.1016/s0306-4522(02)00866-7 (opens in a new tab)PepBankPUB-12710982
Publisher pagePubMedAsk about this study
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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 study9

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

  1. 01AnimalAnimal study (in vivo)Efficacy outcome

    In awake male rats, intracerebroventricular MT-II induced penile erections in a dose-dependent fashion.

    In plain wordsIn male rats, MT-II injected into the brain caused penile erections, more at higher doses.

    Peptide
    Melanotan II
    Outcome
    IncreasePenile erection after i.c.v. MT-II
    Study

    ratn: not reported in source

    Outcome group
    Sexual function · Reproductive and sexual health
    Studied dose
    Dose not stated · intracerebroventricularAs given in this study (rat).

    Source sentences

    Summary
    I.c.v., i.th., and i.v. MT-II induced penile erections in a dose-dependent fashion.
    1 context sentence
    Summary · context
    To elucidate sites of the proerectile action of melanocortin peptides, in awake male rats we administered the MC-R agonist Ac-Nle-c[Asp-His-DPhe-Arg-Trp-Lys]-NH(2) (MT-II) i.c.v., intrathecal (i.th.) and i.v. and scored penile erection and yawning.
  2. 02AnimalAnimal study (in vivo)Efficacy outcome

    In awake male rats, intrathecal MT-II induced penile erections in a dose-dependent fashion.

    In plain wordsIn male rats, MT-II injected around the spinal cord caused penile erections, more at higher doses.

    Peptide
    Melanotan II
    Outcome
    IncreasePenile erection after i.th. MT-II
    Study

    ratn: not reported in source

    Outcome group
    Sexual function · Reproductive and sexual health
    Studied dose
    Dose not stated · intrathecalAs given in this study (rat).

    Source sentences

    Summary
    I.c.v., i.th., and i.v. MT-II induced penile erections in a dose-dependent fashion.
    1 context sentence
    Summary · context
    To elucidate sites of the proerectile action of melanocortin peptides, in awake male rats we administered the MC-R agonist Ac-Nle-c[Asp-His-DPhe-Arg-Trp-Lys]-NH(2) (MT-II) i.c.v., intrathecal (i.th.) and i.v. and scored penile erection and yawning.
  3. 03AnimalAnimal study (in vivo)Efficacy outcome

    In awake male rats, intravenous MT-II induced penile erections in a dose-dependent fashion.

    In plain wordsIn male rats, MT-II injected into a vein caused penile erections, more at higher doses.

    Peptide
    Melanotan II
    Outcome
    IncreasePenile erection after i.v. MT-II
    Study

    ratn: not reported in source

    Outcome group
    Sexual function · Reproductive and sexual health
    Studied dose
    Dose not stated · intravenousAs given in this study (rat).

    Source sentences

    Summary
    I.c.v., i.th., and i.v. MT-II induced penile erections in a dose-dependent fashion.
    1 context sentence
    Summary · context
    To elucidate sites of the proerectile action of melanocortin peptides, in awake male rats we administered the MC-R agonist Ac-Nle-c[Asp-His-DPhe-Arg-Trp-Lys]-NH(2) (MT-II) i.c.v., intrathecal (i.th.) and i.v. and scored penile erection and yawning.
  4. 04AnimalAnimal study (in vivo)Efficacy outcome

    In rats, yawning was observed with intracerebroventricular and intravenous MT-II.

    In plain wordsIn rats, MT-II injected into the brain or into a vein caused yawning.

    Peptide
    Melanotan II
    Outcome
    IncreaseYawning after i.c.v. or i.v. MT-II
    Study

    ratn: not reported in source

    Outcome group
    Locomotor and behavioral activity · Nervous system and cognition
    Studied dose
    Dose not stated · intracerebroventricular and intravenousAs given in this study (rat).

    Source sentences

    Summary
    Yawning was observed with i.c.v. and i.v. MT-II
    1 context sentence
    Summary · context
    To elucidate sites of the proerectile action of melanocortin peptides, in awake male rats we administered the MC-R agonist Ac-Nle-c[Asp-His-DPhe-Arg-Trp-Lys]-NH(2) (MT-II) i.c.v., intrathecal (i.th.) and i.v. and scored penile erection and yawning.
  5. 05AnimalAnimal study (in vivo)Efficacy outcome

    In rats, spinal injection of MT-II did not produce yawning.

    In plain wordsIn rats, MT-II injected around the spinal cord did not cause yawning.

    Peptide
    Melanotan II
    Outcome
    No significant changeYawning after spinal MT-II
    Study

    ratn: not reported in source

    Outcome group
    Locomotor and behavioral activity · Nervous system and cognition
    Studied dose
    Dose not stated · intrathecalAs given in this study (rat).

    Source sentences

    Summary
    Yawning was observed with i.c.v. and i.v. MT-II, while spinal injection did not produce this behavior.
    1 context sentence
    Summary · context
    To elucidate sites of the proerectile action of melanocortin peptides, in awake male rats we administered the MC-R agonist Ac-Nle-c[Asp-His-DPhe-Arg-Trp-Lys]-NH(2) (MT-II) i.c.v., intrathecal (i.th.) and i.v. and scored penile erection and yawning.
  6. 06AnimalAnimal study (in vivo)Efficacy outcome

    In rats, intrathecal MT-II delivery to the lumbosacral spinal cord was more efficacious in inducing erections than intracerebroventricular or intravenous administration.

    In plain wordsIn rats, MT-II given at the lower spinal cord caused erections more effectively than MT-II given into the brain or a vein.

    Peptide
    Melanotan II
    Outcome
    IncreaseErection efficacy of i.th. versus i.c.v. or i.v. MT-II
    Study

    ratn: not reported in source

    Comparator
    i.c.v. or i.v. MT-II
    Outcome group
    Sexual function · Reproductive and sexual health
    Studied dose
    Dose not stated · intrathecalAs given in this study (rat).

    Source sentences

    Summary
    Intrathecal delivery of MT-II to the lumbosacral spinal cord was more efficacious in inducing erections than i.c.v. or i.v. administration
    1 context sentence
    Summary · context
    To elucidate sites of the proerectile action of melanocortin peptides, in awake male rats we administered the MC-R agonist Ac-Nle-c[Asp-His-DPhe-Arg-Trp-Lys]-NH(2) (MT-II) i.c.v., intrathecal (i.th.) and i.v. and scored penile erection and yawning.
  7. 07AnimalAnimal study (in vivo)Efficacy outcome

    In anesthetized rats, intracavernosal MT-II did not increase intracavernous pressure.

    In plain wordsIn anesthetized rats, MT-II injected into the penis did not raise pressure in the penis.

    Peptide
    Melanotan II
    Outcome
    No significant changeIntracavernous pressure after intracavernosal MT-II
    Study

    ratn: not reported in source

    Outcome group
    Sexual function · Reproductive and sexual health
    Studied dose
    Dose not stated · intracavernosalAs given in this study (rat).

    Source sentences

    Summary
    Intracavernosal MT-II neither increased intracavernous pressure
    1 context sentence
    Summary · context
    To exclude a site of action in the penis, we recorded intracavernous pressure responses to intracavernosal injection of MT-II in the anesthetized rat
  8. 08AnimalAnimal study (in vivo)Efficacy outcome

    In anesthetized rats, intracavernosal MT-II did not augment neurostimulated erectile responses.

    In plain wordsIn anesthetized rats, MT-II injected into the penis did not strengthen erections caused by nerve stimulation.

    Peptide
    Melanotan II
    Outcome
    No significant changeNeurostimulated erectile responses after intracavernosal MT-II
    Study

    ratn: not reported in source

    Outcome group
    Sexual function · Reproductive and sexual health
    Studied dose
    Dose not stated · intracavernosalAs given in this study (rat).

    Source sentences

    Summary
    Intracavernosal MT-II neither increased intracavernous pressure nor augmented neurostimulated erectile responses.
    1 context sentence
    Summary · context
    To exclude a site of action in the penis, we recorded intracavernous pressure responses to intracavernosal injection of MT-II in the anesthetized rat

Studies that did not test the peptide alone1

In this study, Melanotan II 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 Melanotan II.

  1. 09AnimalNot a test of Melanotan II aloneAnimal study (in vivo)Efficacy outcome

    In rats, the antagonist SHU-9119 blocked the erectile responses to intrathecal MT-II.

    In plain wordsIn rats, the blocker SHU-9119 stopped the erections caused by MT-II given at the spinal cord.

    Peptide
    Melanotan II
    Outcome
    DecreaseErectile responses to i.th. MT-II with SHU-9119
    Study

    ratn: not reported in source

    Outcome group
    Sexual function · Reproductive and sexual health

    Source sentences

    Summary
    SHU-9119 blocked the erectile responses to i.th.
    1 context sentence
    Summary · context
    To elucidate sites of the proerectile action of melanocortin peptides, in awake male rats we administered the MC-R agonist Ac-Nle-c[Asp-His-DPhe-Arg-Trp-Lys]-NH(2) (MT-II) i.c.v., intrathecal (i.th.) and i.v. and scored penile erection and yawning.

    In this study, Melanotan II 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 Melanotan II.

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 2Current

    10 Oct 2026, 09:43 UTC

    Study results updated

  2. Version 1

    9 Oct 2026, 03:04 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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