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

5 results

Exploring the site of anorectic action of peripherally administered synthetic melanocortin peptide MT-II in rats.

Trivedi P, Jiang M, Tamvakopoulos CC, Shen X, Yu H, Mock S, Fenyk-Melody J, Van der Ploeg LH, Guan XM

Brain research1 Jul 2003Cited by 44 (Europe PMC)

PMID12834882 (opens in a new tab)DOI10.1016/s0006-8993(03)02683-0 (opens in a new tab)PepBankPUB-12834882
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 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 rats, intravenous MT-II and iodo-MT-II were both effective at suppressing appetite.

    In plain wordsIn rats, MT-II given into a vein reduced appetite, as did its iodinated form.

    Peptide
    Melanotan II
    Outcome
    DecreaseAppetite suppression after intravenous MT-II
    Study

    ratn: not reported in source

    Outcome group
    Appetite and food intake · Metabolic and weight
    Studied dose
    Dose not stated · intravenousAs given in this study (rat).

    Source sentences

    Summary
    Firstly, both MT-II and iodo-MT-II were effective at suppressing appetite in rats following their IV administration.
  2. 02AnimalAnimal study (in vivo)Pharmacokinetics

    After intravenous (125)I-MT-II in rats, significant radioactivity was not detected in brain regions by autoradiography except in circumventricular organs outside the blood-brain barrier.

    In plain wordsIn rats, radiolabelled MT-II given into a vein did not reach most brain regions, apart from areas outside the blood-brain barrier.

    Peptide
    Melanotan II
    Outcome
    Not applicableBrain distribution of intravenous (125)I-MT-II
    Study

    ratn: not reported in source

    Outcome group
    Pharmacokinetics · Pharmacology
    Studied dose
    Dose not stated · intravenousAs given in this study (rat).

    Source sentences

    Summary
    Upon IV administration of (125)I-MT-II, significant radioactivity could not be detected in various brain regions by autoradiography except for a group of circumventricular organs (CVOs), which are anatomically situated outside the blood-brain barrier (BBB).
  3. 03AnimalAnimal study (in vivo)Mechanism

    In rats, accumulation of radioactivity at the most intensely labeled circumventricular organs was blocked by co-injection of excess unlabeled MT-II.

    In plain wordsIn rats, extra unlabelled MT-II blocked the build-up of labelled MT-II in brain areas outside the blood-brain barrier.

    Peptide
    Melanotan II
    Outcome
    DecreaseBlocking of MT-II accumulation at circumventricular organs
    Study

    ratn: not reported in source

    Comparator
    Excess unlabeled MT-II
    Outcome group
    Receptor activity and mechanism · Nervous system and cognition
    Studied dose
    Dose not stated · intravenousAs given in this study (rat).

    Source sentences

    Summary
    The most intensely labeled CVOs include the subfornical organ, median eminence, area postrema and choroid plexus, and accumulation of radioactivity at these sites can be blocked by co-injection of excess unlabeled MT-II.
  4. 04AnimalAnimal study (in vivo)Pharmacokinetics

    In rats, LC-MS-MS measurement in brain and plasma after intravenous MT-II confirmed that brain penetration is negligible.

    In plain wordsIn rats, direct measurement showed almost no MT-II entering the brain after injection into a vein.

    Peptide
    Melanotan II
    Outcome
    Not applicableBrain penetration of MT-II measured by LC-MS-MS
    Study

    ratn: not reported in source

    Outcome group
    Pharmacokinetics · Pharmacology
    Studied dose
    Dose not stated · intravenousAs given in this study (rat).

    Source sentences

    Summary
    Direct measurement of MT-II in the brain and plasma by LC-MS-MS following IV injection confirmed that the degree of MT-II penetration into the brain is negligible.
  5. 05AnimalAnimal study (in vivo)Mechanism

    In rats, peripheral MT-II at food-suppressing doses did not produce detectable c-Fos-like immunoreactivity in brain regions where intracerebroventricular MT-II raised c-Fos expression.

    In plain wordsIn rats, MT-II given outside the brain did not switch on the brain activity marker c-Fos that brain injection did.

    Peptide
    Melanotan II
    Outcome
    No significant changec-Fos-like immunoreactivity in brain after peripheral MT-II
    Study

    ratn: not reported in source

    Comparator
    Intracerebroventricular MT-II
    Outcome group
    Receptor activity and mechanism · Nervous system and cognition
    Studied dose
    Dose not stated · peripheralAs given in this study (rat).

    Source sentences

    Summary
    Furthermore, when given peripherally under conditions that suppressed food intake, MT-II did not result in a detectable induction of c-Fos-like immunoreactivity in brain regions where a significantly elevated c-Fos expression was observed following intracerebroventricular injection of this peptide.

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

    9 Oct 2026, 18:17 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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