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

5 results

MT-II induces penile erection via brain and spinal mechanisms.

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

Annals of the New York Academy of Sciences1 Jun 2003Cited by 22 (Europe PMC)

PMID12851302 (opens in a new tab)DOI10.1111/j.1749-6632.2003.tb03166.x (opens in a new tab)PepBankPUB-12851302
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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 study5

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

  1. 01AnimalAnimal study (in vivo)Efficacy outcome

    In male rats, MT-II induced penile erections dose-dependently after intracerebroventricular and intrathecal injection, with an optimal response at 1 microg.

    In plain wordsIn male rats, MT-II caused penile erections, and the effect grew with the dose when injected into the brain or the spinal canal.

    Peptide
    Melanotan II
    Outcome
    IncreasePenile erection
    Study

    ratn: not reported in source

    Outcome group
    Sexual function · Reproductive and sexual health
    Studied dose
    1 microg (optimal response) · i.c.v. and i.th.As given in this study (rat).

    Measurements

    optimal dose
    1 µg
    i.c.v. and i.th.

    Source sentences

    Summary
    MT-II induced penile erections in a dose-dependent fashion, with optimal response at 1 microg for both i.c.v. and i.th. routes.
    1 context sentence
    Summary · context
    We administered MT-II intracerebroventribularly (i.c.v.), intrathecally (i.th.), and intravenously (i.v.) and scored penile erection and yawning for 90 min in awake male rats.
  2. 02AnimalAnimal study (in vivo)Efficacy outcome

    In male rats, yawning occurred with intracerebroventricular and intravenous MT-II, but not with spinal (intrathecal) injection.

    In plain wordsIn rats, MT-II caused yawning after injection into the brain or the vein, but not into the spinal canal.

    Peptide
    Melanotan II
    Outcome
    MixedYawning
    Study

    ratn: not reported in source

    Outcome group
    Locomotor and behavioral activity · Nervous system and cognition
    Studied dose
    Dose not stated · i.c.v., i.th. and i.v.As given in this study (rat).

    Source sentences

    Summary
    Yawning was observed with i.c.v. and i.v. MT-II, whereas spinal injection did not produce this behavior.
    1 context sentence
    Summary · context
    We administered MT-II intracerebroventribularly (i.c.v.), intrathecally (i.th.), and intravenously (i.v.) and scored penile erection and yawning for 90 min in awake male rats.
  3. 03AnimalAnimal study (in vivo)Mechanism

    In male rats, 1 microg SHU-9119 given intracerebroventricularly completely suppressed erections induced by supraspinal MT-II.

    In plain wordsIn rats, a receptor blocker given into the brain fully stopped the erections caused by MT-II in the brain.

    Peptide
    Melanotan II
    Outcome
    Not applicableBlockade of supraspinal MT-II erections by SHU-9119
    Study

    ratn: not reported in source

    Outcome group
    Receptor activity and mechanism · Reproductive and sexual health
    Studied dose
    Dose not stated · i.c.v.As given in this study (rat).

    Source sentences

    Summary
    Supraspinal MT-II-induced erections were completely suppressed by 1 microg SHU-9119 i.c.v.
    1 context sentence
    Summary · context
    We administered MT-II intracerebroventribularly (i.c.v.), intrathecally (i.th.), and intravenously (i.v.) and scored penile erection and yawning for 90 min in awake male rats.
  4. 04AnimalAnimal study (in vivo)Mechanism

    In male rats, SHU-9119 blocked the erectile responses to intrathecal MT-II when it was injected intrathecally, but not when it was injected intracerebroventricularly.

    In plain wordsIn rats, a receptor blocker in the spinal canal stopped erections from MT-II given there. One given in the brain did not.

    Peptide
    Melanotan II
    Outcome
    Not applicableBlockade of spinal MT-II erections by SHU-9119
    Study

    ratn: not reported in source

    Outcome group
    Receptor activity and mechanism · Reproductive and sexual health
    Studied dose
    Dose not stated · i.th.As given in this study (rat).

    Source sentences

    Summary
    SHU-9119 blocked the erectile responses to i.th. MT-II when injected i.th. but not i.c.v. Intracavernosal MT-II neither increased intracorporal pressure nor augmented neurostimulated erectile responses.
    1 context sentence
    Summary · context
    We administered MT-II intracerebroventribularly (i.c.v.), intrathecally (i.th.), and intravenously (i.v.) and scored penile erection and yawning for 90 min in awake male rats.
  5. 05AnimalAnimal study (in vivo)Efficacy outcome

    In anaesthetised male rats, intracavernosal MT-II neither increased intracorporal pressure nor augmented neurostimulated erectile responses.

    In plain wordsIn anaesthetised rats, MT-II injected into the penis did not raise erection pressure or boost nerve-triggered erections.

    Peptide
    Melanotan II
    Outcome
    No significant changeIntracorporal 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 intracorporal pressure nor augmented neurostimulated erectile responses.
    1 context sentence
    Summary · context
    To exclude a site of action in the penis, we recorded intracorporal pressure responses to intracavernosal injection of MT-II in the anesthetized rat.

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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