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Study · Animal study (in vivo) · rat · 2004

4 results

Aged-obese rats exhibit robust responses to a melanocortin agonist and antagonist despite leptin resistance.

Zhang Y, Matheny M, Tümer N, Scarpace PJ

Neurobiology of aging1 Nov 2004Cited by 37 (Europe PMC)

PMID15465633 (opens in a new tab)DOI10.1016/j.neurobiolaging.2004.02.012 (opens in a new tab)PepBankPUB-15465633
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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 study4

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

  1. 01AnimalAnimal study (in vivo)Efficacy outcome

    In young and old rats, centrally infused melanotan II caused anorexia that was transient.

    In plain wordsIn young and old rats, melanotan II infused into the brain reduced eating, but only for a short time.

    Peptide
    Melanotan II
    Outcome
    DecreaseAnorexia (food intake) after MTII
    Study

    ratn: not reported in source

    Young and old (aged-obese) rats
    Outcome group
    Appetite and food intake · Metabolic and weight
    Studied dose
    Dose not stated · central infusionAs given in this study (rat).

    Source sentences

    Summary
    The MTII-evoked anorexia was transient whereas the SHU9119-induced hyperphagia was sustained in young and old.
    1 context sentence
    Summary · context
    To address whether defective melanocortin activation is one element of leptin resistance with age, we infused centrally the melanocortin agonist, MTII and antagonist, SHU9119 in young and old rats.
  2. 02AnimalAnimal study (in vivo)Efficacy outcome

    In young and old rats, melanotan II elevated oxygen consumption.

    In plain wordsIn young and old rats, melanotan II raised oxygen use.

    Peptide
    Melanotan II
    Outcome
    IncreaseOxygen consumption after MTII
    Study

    ratn: not reported in source

    Young and old (aged-obese) rats
    Outcome group
    Energy expenditure and thermogenesis · Metabolic and weight
    Studied dose
    Dose not stated · central infusionAs given in this study (rat).

    Source sentences

    Summary
    MTII elevated oxygen consumption in both ages.
    1 context sentence
    Summary · context
    To address whether defective melanocortin activation is one element of leptin resistance with age, we infused centrally the melanocortin agonist, MTII and antagonist, SHU9119 in young and old rats.
  3. 03AnimalAnimal study (in vivo)Efficacy outcome

    After melanotan II infusion, oxygen consumption waned gradually in young rats but increased continuously in aged rats.

    In plain wordsAfter melanotan II, oxygen use faded in young rats but kept rising in old rats.

    Peptide
    Melanotan II
    Outcome
    MixedTime course of oxygen consumption after MTII, young versus aged
    Study

    ratn: not reported in source

    Young and old (aged-obese) rats
    Comparator
    Young rats
    Outcome group
    Energy expenditure and thermogenesis · Metabolic and weight
    Studied dose
    Dose not stated · central infusionAs given in this study (rat).

    Source sentences

    Summary
    The oxygen consumption waned gradually in young but increased continuously in aged following MTII infusion.
    1 context sentence
    Summary · context
    To address whether defective melanocortin activation is one element of leptin resistance with age, we infused centrally the melanocortin agonist, MTII and antagonist, SHU9119 in young and old rats.
  4. 04AnimalAnimal study (in vivo)Mechanism

    In young and old rats, melanotan II induced brown adipose tissue UCP1 to a similarly robust extent.

    In plain wordsIn young and old rats, melanotan II raised a heat-producing protein (UCP1) in brown fat about equally.

    Peptide
    Melanotan II
    Outcome
    IncreaseBrown adipose tissue UCP1 induction by MTII
    Study

    ratn: not reported in source

    Young and old (aged-obese) rats
    Outcome group
    Energy expenditure and thermogenesis · Metabolic and weight
    Studied dose
    Dose not stated · central infusionAs given in this study (rat).

    Source sentences

    Summary
    The MTII-mediated induction in BAT UCP1 was similarly robust in both ages
    1 context sentence
    Summary · context
    To address whether defective melanocortin activation is one element of leptin resistance with age, we infused centrally the melanocortin agonist, MTII and antagonist, SHU9119 in young and old rats.

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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