Effects of alpha-melanocyte-stimulating hormone on magnocellular oxytocin neurones and their activation at intromission in male rats.

Caquineau C, Leng G, Guan XM, Jiang M, Van der Ploeg L, Douglas AJ

Journal of neuroendocrinology1 Sept 2006Cited by 45 (Europe PMC)

PMID16879167DOI10.1111/j.1365-2826.2006.01465.xPepBankPUB-16879167

Publisher page PubMedAsk about this study

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

No result from this study comes from a test of the peptide.

Studies that did not test the peptide alone6

In this study, Oxytocin 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 Oxytocin.

01AnimalNot a test of Oxytocin aloneAnimal study (in vivo)Mechanism
In male rats showing intromission, Fos was expressed in magnocellular oxytocin neurones of the paraventricular and supraoptic nuclei.
In plain wordsIn rats, mating activated the nerve cells that make oxytocin in two brain areas.
Peptide
Oxytocin
Outcome
IncreaseFos in magnocellular oxytocin neurones at intromission
Study
ratn: not reported in source
Outcome group
Sex hormones and fertility · Reproductive and sexual health
Source sentences
Summary
In rats that showed intromission, Fos was expressed in magnocellular oxytocin neurones in both the paraventricular nucleus (PVN) and the supraoptic nucleus (SON)
1 context sentence(design, population, supporting numbers)
Summary · context
Here, we used intromission as a physiological stimulus to investigate whether some central effects of alpha-MSH during male sexual behaviour are mediated by oxytocin neurones.
In this study, Oxytocin 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 Oxytocin.
Report a problemFND-1687916701
02AnimalNot a test of Oxytocin aloneAnimal study (in vivo)Mechanism
In male rats showing intromission, there was no significant activation of parvocellular oxytocin neurones of the paraventricular nucleus.
In plain wordsIn rats, mating did not clearly activate the smaller oxytocin nerve cells in one brain area.
Peptide
Oxytocin
Outcome
No significant changeFos in parvocellular oxytocin neurones at intromission
Study
ratn: not reported in source
Outcome group
Sex hormones and fertility · Reproductive and sexual health
Source sentences
Summary
but there was no significant activation of parvocellular oxytocin neurones of the PVN.
1 context sentence(design, population, supporting numbers)
Summary · context
Here, we used intromission as a physiological stimulus to investigate whether some central effects of alpha-MSH during male sexual behaviour are mediated by oxytocin neurones.
In this study, Oxytocin 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 Oxytocin.
Report a problemFND-1687916702
03AnimalNot a test of Oxytocin aloneAnimal study (in vivo)Mechanism
In male rats, intracerebroventricular alpha-MSH increased Fos expression in magnocellular oxytocin neurones.
In plain wordsIn rats, the hormone alpha-MSH activated the large oxytocin nerve cells.
Peptide
Oxytocin
Outcome
IncreaseFos in magnocellular oxytocin neurones after alpha-MSH
Study
ratn: not reported in source
Outcome group
Sex hormones and fertility · Reproductive and sexual health
Source sentences
Summary
alpha-MSH increased Fos expression in magnocellular oxytocin neurones but had little or no effect in parvocellular oxytocin neurones.
1 context sentence(design, population, supporting numbers)
Summary · context
Here, we used intromission as a physiological stimulus to investigate whether some central effects of alpha-MSH during male sexual behaviour are mediated by oxytocin neurones.
In this study, Oxytocin 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 Oxytocin.
Report a problemFND-1687916703
04AnimalNot a test of Oxytocin aloneAnimal study (in vivo)Mechanism
In male rats, alpha-MSH had little or no effect in parvocellular oxytocin neurones.
In plain wordsIn rats, alpha-MSH had little or no effect on the smaller oxytocin nerve cells.
Peptide
Oxytocin
Outcome
No significant changeFos in parvocellular oxytocin neurones after alpha-MSH
Study
ratn: not reported in source
Outcome group
Sex hormones and fertility · Reproductive and sexual health
Source sentences
Summary
but had little or no effect in parvocellular oxytocin neurones.
1 context sentence(design, population, supporting numbers)
Summary · context
Here, we used intromission as a physiological stimulus to investigate whether some central effects of alpha-MSH during male sexual behaviour are mediated by oxytocin neurones.
In this study, Oxytocin 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 Oxytocin.
Report a problemFND-1687916704
05AnimalNot a test of Oxytocin aloneAnimal study (in vivo)Mechanism
In male rats that achieved intromission, a MC4 receptor antagonist significantly attenuated the increase in Fos expression in magnocellular oxytocin neurones of the paraventricular and supraoptic nuclei compared with vehicle.
In plain wordsIn rats, a drug that blocks MC4 receptors reduced the activation of large oxytocin nerve cells during mating, compared with vehicle.
Peptide
Oxytocin
Outcome
DecreaseFos in magnocellular oxytocin neurones after MC4 receptor antagonist at intromission
Study
ratn: not reported in source
Comparator
Vehicle
Outcome group
Sex hormones and fertility · Reproductive and sexual health
Source sentences
Summary
In male rats that achieved intromission, central injection of a MC4 receptor antagonist significantly attenuated the increase in Fos expression in magnocellular oxytocin neurones in both the PVN and the SON
1 context sentence(design, population, supporting numbers)
Summary · context
Here, we used intromission as a physiological stimulus to investigate whether some central effects of alpha-MSH during male sexual behaviour are mediated by oxytocin neurones.
In this study, Oxytocin 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 Oxytocin.
Report a problemFND-1687916705
06AnimalNot a test of Oxytocin aloneAnimal study (in vivo)Mechanism
In male rats, a MC4 receptor antagonist increased mount and intromission latencies compared with vehicle-injected controls.
In plain wordsIn rats, a MC4 receptor blocker made males slower to start mating, compared with vehicle.
Peptide
Oxytocin
Outcome
IncreaseMount and intromission latency after MC4 receptor antagonist
Study
ratn: not reported in source
Comparator
Vehicle
Outcome group
Sexual function · Reproductive and sexual health
Source sentences
Summary
and increased mount and intromission latencies compared to vehicle-injected controls.
1 context sentence(design, population, supporting numbers)
Summary · context
Here, we used intromission as a physiological stimulus to investigate whether some central effects of alpha-MSH during male sexual behaviour are mediated by oxytocin neurones.
In this study, Oxytocin 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 Oxytocin.
Report a problemFND-1687916706

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
11 Oct 2026, 20:03 UTC
Study results updated
Version 1
9 Oct 2026, 02:50 UTC
First added · source update from Europe PMC

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