Activation of the melanocortin-4 receptor mobilizes intracellular free calcium in immortalized hypothalamic neurons.

Newman EA, Chai BX, Zhang W, Li JY, Ammori JB, Mulholland MW

The Journal of surgical research31 Mar 2006Cited by 57 (Europe PMC)

PMID16580690DOI10.1016/j.jss.2006.02.003PepBankPUB-16580690

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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 study6

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

01LabIn vitro (cells)Activity measurement
In immortalized hypothalamic GT1-1 neurons, NDP-alphaMSH caused dose-dependent increases in intracellular calcium.
In plain wordsIn cells, NDP-alphaMSH raised calcium inside hypothalamic neurons in a dose-dependent way.
Peptide
Melanotan I (afamelanotide)
Outcome
IncreaseIntracellular calcium after agonist treatment
Study
n: not reported in source
Immortalized hypothalamic GT1-1 neurons
Outcome group
Receptor activity and mechanism · Nervous system and cognition
Studied dose
Dose not stated
Source sentences
Summary
Agonist treatment (0.01-1000 nm) of GT1-1 neurons resulted in dose-dependent increases in intracellular calcium.
1 context sentence(design, population, supporting numbers)
Summary · context
Cells were treated with NDP-alphaMSH, an alpha-melanocortin stimulating hormone analogue, and intracellular calcium changes were recorded.
Report a problemFND-1658069001

Studies that did not test the peptide alone5

In this study, Melanotan I (afamelanotide) 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 I (afamelanotide).

02LabNot a test of Melanotan I (afamelanotide) aloneIn vitro (cells)Mechanism
In GT1-1 neurons, the antagonist SHU-9119 abolished the calcium response to NDP-alphaMSH.
In plain wordsIn cells, the blocker SHU-9119 removed the calcium response to NDP-alphaMSH.
Peptide
Melanotan I (afamelanotide)
Outcome
DecreaseNDP-alphaMSH calcium response with SHU-9119
Study
n: not reported in source
Immortalized hypothalamic GT1-1 neurons
Comparator
NDP-alphaMSH alone
Outcome group
Receptor activity and mechanism · Nervous system and cognition
Source sentences
Summary
SHU-9119 (0.01-1000 nm) abolished the calcium response.
2 context sentences(design, population, supporting numbers)
Summary · context
Cells treated with NDP-alpha-MSH were also treated with the melanocortin-4 receptor antagonist, SHU-9119.
Summary · context
Cells were treated with NDP-alphaMSH, an alpha-melanocortin stimulating hormone analogue, and intracellular calcium changes were recorded.
In this study, Melanotan I (afamelanotide) 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 I (afamelanotide).
Report a problemFND-1658069002
03LabNot a test of Melanotan I (afamelanotide) aloneIn vitro (cells)Mechanism
In GT1-1 neurons, the phospholipase C inhibitor U73122 attenuated the calcium response to NDP-alphaMSH.
In plain wordsIn cells, the enzyme blocker U73122 reduced the calcium response to NDP-alphaMSH.
Peptide
Melanotan I (afamelanotide)
Outcome
DecreaseNDP-alphaMSH calcium response with U73122
Study
n: not reported in source
Immortalized hypothalamic GT1-1 neurons
Outcome group
Receptor activity and mechanism · Nervous system and cognition
Source sentences
Summary
Treatment with U73122 (10 microm) attenuated the calcium response
1 context sentence(design, population, supporting numbers)
Summary · context
Cells were treated with NDP-alphaMSH, an alpha-melanocortin stimulating hormone analogue, and intracellular calcium changes were recorded.
In this study, Melanotan I (afamelanotide) 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 I (afamelanotide).
Report a problemFND-1658069003
04LabNot a test of Melanotan I (afamelanotide) aloneIn vitro (cells)Mechanism
In GT1-1 neurons, the inactive analogue U73433 had minimal effect on the calcium response to NDP-alphaMSH.
In plain wordsIn cells, the inactive compound U73433 had little effect on the NDP-alphaMSH calcium response.
Peptide
Melanotan I (afamelanotide)
Outcome
No significant changeNDP-alphaMSH calcium response with U73433
Study
n: not reported in source
Immortalized hypothalamic GT1-1 neurons
Outcome group
Receptor activity and mechanism · Nervous system and cognition
Source sentences
Summary
while U73433 (10 microm) had minimal effect.
1 context sentence(design, population, supporting numbers)
Summary · context
Cells were treated with NDP-alphaMSH, an alpha-melanocortin stimulating hormone analogue, and intracellular calcium changes were recorded.
In this study, Melanotan I (afamelanotide) 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 I (afamelanotide).
Report a problemFND-1658069004
05LabNot a test of Melanotan I (afamelanotide) aloneIn vitro (cells)Mechanism
In GT1-1 neurons, the IP3 receptor inhibitor 2APB inhibited the calcium transient.
In plain wordsIn cells, the IP3 receptor blocker 2APB reduced the calcium rise.
Peptide
Melanotan I (afamelanotide)
Outcome
DecreaseNDP-alphaMSH calcium transient with 2APB
Study
n: not reported in source
Immortalized hypothalamic GT1-1 neurons
Outcome group
Receptor activity and mechanism · Nervous system and cognition
Source sentences
Summary
2APB (200 microm) inhibited the calcium transient
2 context sentences(design, population, supporting numbers)
Summary · context
Experiments were also performed after inhibition of IP3 receptors with 2-aminoethoxydiphenylborate (2APB).
Summary · context
Cells were treated with NDP-alphaMSH, an alpha-melanocortin stimulating hormone analogue, and intracellular calcium changes were recorded.
In this study, Melanotan I (afamelanotide) 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 I (afamelanotide).
Report a problemFND-1658069005
06LabNot a test of Melanotan I (afamelanotide) aloneIn vitro (cells)Mechanism
In GT1-1 neurons, calcium-free buffer did not change the amplitude of the calcium spike.
In plain wordsIn cells, removing calcium from the buffer did not change the size of the calcium spike.
Peptide
Melanotan I (afamelanotide)
Outcome
No significant changeNDP-alphaMSH calcium spike in calcium-free buffer
Study
n: not reported in source
Immortalized hypothalamic GT1-1 neurons
Outcome group
Receptor activity and mechanism · Nervous system and cognition
Source sentences
Summary
and the use of calcium-free buffer did not affect the amplitude of the calcium spike.
2 context sentences(design, population, supporting numbers)
Summary · context
Additional experiments were conducted in a calcium-depleted buffer environment.
Summary · context
Cells were treated with NDP-alphaMSH, an alpha-melanocortin stimulating hormone analogue, and intracellular calcium changes were recorded.
In this study, Melanotan I (afamelanotide) 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 I (afamelanotide).
Report a problemFND-1658069006

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
13 Oct 2026, 21:44 UTC
Study results updated
Version 1
13 Oct 2026, 16:31 UTC
First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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