Does obesity induce resistance to the long-term cardiovascular and metabolic actions of melanocortin 3/4 receptor activation?

Silva AA, Kuo JJ, Tallam LS, Liu J, Hall JE

Hypertension (Dallas, Tex. : 1979)27 Dec 2005Cited by 22 (Europe PMC)

PMID16380516DOI10.1161/01.hyp.0000198458.70351.e0PepBankPUB-16380516

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 study6

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

01AnimalAnimal study (in vivo)Efficacy outcome
In rats fed a high-fat diet, chronic intracerebroventricular MTII infusion increased mean arterial pressure by 7 mm Hg.
In plain wordsIn obese rats, MTII infused into the brain raised blood pressure by 7 mm Hg.
Peptide
Melanotan II
Outcome
IncreaseMean arterial pressure change in HF rats
Study
ratn = 6
Sprague-Dawley rats on a high-fat diet for 12 months
Comparator
Pre-infusion control period
Outcome group
Blood pressure · Cardiovascular
Studied dose
10 ng/h · intracerebroventricular infusion · 10 daysAs given in this study (rat).
Measurements
MAP change
7 mm Hg
HF rats
Source sentences
Summary
Chronic melanotan II infusion significantly increased MAP in HF and NF (7+/-2 and 6+/-1 mm Hg), decreased caloric intake (-32+/-2 and -25 +/-2 kcal/day), and reduced insulin levels in both groups by approximately 50%.
2 context sentences(design, population, supporting numbers)
Summary · context
Therefore, we tested whether the cardiovascular and metabolic actions of MC3/4-R activation are attenuated in Sprague-Dawley rats fed a high-fat diet (HF, n=6) compared with rats fed a standard chow (NF, n=6) for 12 months.
Summary · context
After a 5-day control period, rats were infused with MC3/4-R agonist melanotan II (10 ng/h, ICV), for 10 days followed by a 5-day recovery period.
Report a problemFND-1638051601
02AnimalAnimal study (in vivo)Efficacy outcome
In rats fed standard chow, chronic intracerebroventricular MTII infusion increased mean arterial pressure by 6 mm Hg.
In plain wordsIn rats fed standard chow, MTII infused into the brain raised blood pressure by 6 mm Hg.
Peptide
Melanotan II
Outcome
IncreaseMean arterial pressure change in NF rats
Study
ratn = 6
Sprague-Dawley rats on standard chow for 12 months
Comparator
Pre-infusion control period
Outcome group
Blood pressure · Cardiovascular
Studied dose
10 ng/h · intracerebroventricular infusion · 10 daysAs given in this study (rat).
Measurements
MAP change
6 mm Hg
NF rats
Source sentences
Summary
Chronic melanotan II infusion significantly increased MAP in HF and NF (7+/-2 and 6+/-1 mm Hg), decreased caloric intake (-32+/-2 and -25 +/-2 kcal/day), and reduced insulin levels in both groups by approximately 50%.
2 context sentences(design, population, supporting numbers)
Summary · context
Therefore, we tested whether the cardiovascular and metabolic actions of MC3/4-R activation are attenuated in Sprague-Dawley rats fed a high-fat diet (HF, n=6) compared with rats fed a standard chow (NF, n=6) for 12 months.
Summary · context
After a 5-day control period, rats were infused with MC3/4-R agonist melanotan II (10 ng/h, ICV), for 10 days followed by a 5-day recovery period.
Report a problemFND-1638051602
03AnimalAnimal study (in vivo)Efficacy outcome
In rats fed a high-fat diet, chronic intracerebroventricular MTII infusion decreased caloric intake by 32 kcal/day.
In plain wordsIn obese rats, MTII infused into the brain reduced food energy intake by 32 kcal per day.
Peptide
Melanotan II
Outcome
DecreaseCaloric intake change in HF rats
Study
ratn = 6
Sprague-Dawley rats on a high-fat diet for 12 months
Comparator
Pre-infusion control period
Outcome group
Appetite and food intake · Metabolic and weight
Studied dose
10 ng/h · intracerebroventricular infusion · 10 daysAs given in this study (rat).
Measurements
Caloric intake change
−32 kcal/day
HF rats
Source sentences
Summary
Chronic melanotan II infusion significantly increased MAP in HF and NF (7+/-2 and 6+/-1 mm Hg), decreased caloric intake (-32+/-2 and -25 +/-2 kcal/day), and reduced insulin levels in both groups by approximately 50%.
2 context sentences(design, population, supporting numbers)
Summary · context
Therefore, we tested whether the cardiovascular and metabolic actions of MC3/4-R activation are attenuated in Sprague-Dawley rats fed a high-fat diet (HF, n=6) compared with rats fed a standard chow (NF, n=6) for 12 months.
Summary · context
After a 5-day control period, rats were infused with MC3/4-R agonist melanotan II (10 ng/h, ICV), for 10 days followed by a 5-day recovery period.
Report a problemFND-1638051603
04AnimalAnimal study (in vivo)Efficacy outcome
In rats fed standard chow, chronic intracerebroventricular MTII infusion decreased caloric intake by 25 kcal/day.
In plain wordsIn rats fed standard chow, MTII infused into the brain reduced food energy intake by 25 kcal per day.
Peptide
Melanotan II
Outcome
DecreaseCaloric intake change in NF rats
Study
ratn = 6
Sprague-Dawley rats on standard chow for 12 months
Comparator
Pre-infusion control period
Outcome group
Appetite and food intake · Metabolic and weight
Studied dose
10 ng/h · intracerebroventricular infusion · 10 daysAs given in this study (rat).
Measurements
Caloric intake change
−25 kcal/day
NF rats
Source sentences
Summary
Chronic melanotan II infusion significantly increased MAP in HF and NF (7+/-2 and 6+/-1 mm Hg), decreased caloric intake (-32+/-2 and -25 +/-2 kcal/day), and reduced insulin levels in both groups by approximately 50%.
2 context sentences(design, population, supporting numbers)
Summary · context
Therefore, we tested whether the cardiovascular and metabolic actions of MC3/4-R activation are attenuated in Sprague-Dawley rats fed a high-fat diet (HF, n=6) compared with rats fed a standard chow (NF, n=6) for 12 months.
Summary · context
After a 5-day control period, rats were infused with MC3/4-R agonist melanotan II (10 ng/h, ICV), for 10 days followed by a 5-day recovery period.
Report a problemFND-1638051604
05AnimalAnimal study (in vivo)Efficacy outcome
In rats fed a high-fat diet, chronic intracerebroventricular MTII infusion reduced insulin levels by approximately 50%.
In plain wordsIn obese rats, MTII infused into the brain cut insulin levels by about half.
Peptide
Melanotan II
Outcome
DecreaseInsulin level change in HF rats
Study
ratn = 6
Sprague-Dawley rats on a high-fat diet for 12 months
Comparator
Pre-infusion control period
Outcome group
Glycemic control · Metabolic and weight
Studied dose
10 ng/h · intracerebroventricular infusion · 10 daysAs given in this study (rat).
Measurements
Insulin level reduction
≈ 50%
HF rats
Source sentences
Summary
Chronic melanotan II infusion significantly increased MAP in HF and NF (7+/-2 and 6+/-1 mm Hg), decreased caloric intake (-32+/-2 and -25 +/-2 kcal/day), and reduced insulin levels in both groups by approximately 50%.
2 context sentences(design, population, supporting numbers)
Summary · context
Therefore, we tested whether the cardiovascular and metabolic actions of MC3/4-R activation are attenuated in Sprague-Dawley rats fed a high-fat diet (HF, n=6) compared with rats fed a standard chow (NF, n=6) for 12 months.
Summary · context
After a 5-day control period, rats were infused with MC3/4-R agonist melanotan II (10 ng/h, ICV), for 10 days followed by a 5-day recovery period.
Report a problemFND-1638051605
06AnimalAnimal study (in vivo)Efficacy outcome
In rats fed standard chow, chronic intracerebroventricular MTII infusion reduced insulin levels by approximately 50%.
In plain wordsIn rats fed standard chow, MTII infused into the brain cut insulin levels by about half.
Peptide
Melanotan II
Outcome
DecreaseInsulin level change in NF rats
Study
ratn = 6
Sprague-Dawley rats on standard chow for 12 months
Comparator
Pre-infusion control period
Outcome group
Glycemic control · Metabolic and weight
Studied dose
10 ng/h · intracerebroventricular infusion · 10 daysAs given in this study (rat).
Measurements
Insulin level reduction
≈ 50%
NF rats
Source sentences
Summary
Chronic melanotan II infusion significantly increased MAP in HF and NF (7+/-2 and 6+/-1 mm Hg), decreased caloric intake (-32+/-2 and -25 +/-2 kcal/day), and reduced insulin levels in both groups by approximately 50%.
2 context sentences(design, population, supporting numbers)
Summary · context
Therefore, we tested whether the cardiovascular and metabolic actions of MC3/4-R activation are attenuated in Sprague-Dawley rats fed a high-fat diet (HF, n=6) compared with rats fed a standard chow (NF, n=6) for 12 months.
Summary · context
After a 5-day control period, rats were infused with MC3/4-R agonist melanotan II (10 ng/h, ICV), for 10 days followed by a 5-day recovery period.
Report a problemFND-1638051606

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.

Version 2Current
10 Oct 2026, 09:43 UTC
Study results updated
Version 1
9 Oct 2026, 03:04 UTC
First added · source update from Europe PMC

Subjects

Terms as the source lists them.

Publication types

MeSH terms

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