Activation of GABAA and opioid receptors reduce penile erection induced by hexarelin peptides.

Succu S, Mascia MS, Melis T, Melis MR, Deghenghi R, Argiolas A

Pharmacology, biochemistry, and behavior1 Dec 2003Cited by 6 (Europe PMC)

PMID14643856DOI10.1016/j.pbb.2003.09.012PepBankPUB-14643856

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 study5

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

Studies that did not test the peptide alone5

In this study, Hexarelin 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 Hexarelin.

01AnimalNot a test of Hexarelin aloneAnimal study (in vivo)Efficacy outcome
In male rats, muscimol given into the paraventricular nucleus dose-dependently reduced penile erection induced by the hexarelin analogue EP 80661.
In plain wordsIn male rats, muscimol reduced erections that a hexarelin-like peptide caused, and the reduction grew with dose.
Peptide
Hexarelin
Outcome
DecreasePenile erection induced by EP 80661 with muscimol
Study
ratn: not reported in source
PVN injection with microdialysis in male rats
Outcome group
Sexual function · Reproductive and sexual health
Source sentences
Summary
Muscimol (50, 100 and 200 ng) and morphine (0.1, 0.5, 1 and 5 microg) given into the PVN dose-dependently reduced penile erection induced by EP 80661 (1 microg) injected into the PVN.
1 context sentence(design, population, supporting numbers)
Summary · context
was studied in male rats
In this study, Hexarelin 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 Hexarelin.
Report a problemFND-1464385601
02AnimalNot a test of Hexarelin aloneAnimal study (in vivo)Efficacy outcome
In male rats, morphine given into the paraventricular nucleus dose-dependently reduced penile erection induced by the hexarelin analogue EP 80661.
In plain wordsIn male rats, morphine reduced erections that a hexarelin-like peptide caused, and the reduction grew with dose.
Peptide
Hexarelin
Outcome
DecreasePenile erection induced by EP 80661 with morphine
Study
ratn: not reported in source
PVN injection with microdialysis in male rats
Outcome group
Sexual function · Reproductive and sexual health
Source sentences
Summary
Muscimol (50, 100 and 200 ng) and morphine (0.1, 0.5, 1 and 5 microg) given into the PVN dose-dependently reduced penile erection induced by EP 80661 (1 microg) injected into the PVN.
1 context sentence(design, population, supporting numbers)
Summary · context
was studied in male rats
In this study, Hexarelin 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 Hexarelin.
Report a problemFND-1464385602
03AnimalNot a test of Hexarelin aloneAnimal study (in vivo)Mechanism
In male rats, the reduction of EP 80661-induced erection by muscimol and morphine was parallel to a decrease of the NO2- and NO3- increase in paraventricular dialysate.
In plain wordsIn male rats, the drop in erections went together with a smaller rise in nitric oxide products in the hypothalamus.
Peptide
Hexarelin
Outcome
DecreaseParaventricular NO2- and NO3- increase with EP 80661
Study
ratn: not reported in source
PVN injection with microdialysis in male rats
Outcome group
Receptor activity and mechanism · Reproductive and sexual health
Source sentences
Summary
The reduction of penile erection was parallel to a decrease of the concomitant NO(2)(-) and NO(3)(-) increase that occurs in the paraventricular dialysate in these experimental conditions.
1 context sentence(design, population, supporting numbers)
Summary · context
was studied in male rats
In this study, Hexarelin 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 Hexarelin.
Report a problemFND-1464385603
04AnimalNot a test of Hexarelin aloneAnimal study (in vivo)Mechanism
In male rats, bicuculline given into the paraventricular nucleus prevented the effects of muscimol on EP 80661-induced erection and NO2- increase.
In plain wordsIn male rats, bicuculline blocked the effect of muscimol on erections caused by a hexarelin-like peptide.
Peptide
Hexarelin
Outcome
Not applicableBicuculline prevention of muscimol effect
Study
ratn: not reported in source
PVN injection with microdialysis in male rats
Outcome group
Receptor activity and mechanism · Reproductive and sexual health
Source sentences
Summary
Muscimol and morphine effects on EP 80661-induced penile erection and NO(2)(-) increase were prevented by the prior administration into the PVN of bicuculline (250 ng) and naloxone (5 microg), respectively.
1 context sentence(design, population, supporting numbers)
Summary · context
was studied in male rats
In this study, Hexarelin 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 Hexarelin.
Report a problemFND-1464385604
05AnimalNot a test of Hexarelin aloneAnimal study (in vivo)Mechanism
In male rats, naloxone given into the paraventricular nucleus prevented the effects of morphine on EP 80661-induced erection and NO2- increase.
In plain wordsIn male rats, naloxone blocked the effect of morphine on erections caused by a hexarelin-like peptide.
Peptide
Hexarelin
Outcome
Not applicableNaloxone prevention of morphine effect
Study
ratn: not reported in source
PVN injection with microdialysis in male rats
Outcome group
Receptor activity and mechanism · Reproductive and sexual health
Source sentences
Summary
Muscimol and morphine effects on EP 80661-induced penile erection and NO(2)(-) increase were prevented by the prior administration into the PVN of bicuculline (250 ng) and naloxone (5 microg), respectively.
1 context sentence(design, population, supporting numbers)
Summary · context
was studied in male rats
In this study, Hexarelin 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 Hexarelin.
Report a problemFND-1464385605

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.

PepBank is a research reference. Talk to a doctor before you use any peptide.