Study on the molecular mechanism of antinociception induced by ghrelin in acute pain in mice.
Peptides
; 83: 1-7, 2016 09.
Article
em En
| MEDLINE
| ID: mdl-27474249
ABSTRACT
Ghrelin has been identified as the endogenous ligand for the GHS-R1α (growth hormone secretagogue receptor 1 alpha). Our previous experiments have indicated that ghrelin (i.c.v.) induces antinociceptive effects in acute pain in mice, and the effects were mediated through the central opioid receptors and GHS-R1α. However, which opioid receptor (OR) mediates the antinociceptive effects and the molecular mechanisms are also needed to be further explored. In the present study, the antinociceptive effects of ghrelin (i.c.v.) could be fully antagonized by δ-opioid receptor antagonist NTI. Furthermore, the mRNA and protein levels of δ-opioid peptide PENK and δ-opioid receptor OPRD were increased after i.c.v injection of ghrelin. Thus, it showed that the antinociception of ghrelin was correlated with the GHS-R1α and δ-opioid receptors. To explore which receptor was firstly activated by ghrelin, GHS-R1α antagonist [D-Lys(3)]-GHRP-6 was co-injection (i.c.v.) with deltorphin II (selective δ-opioid receptor agonist). Finally, the antinociception induced by deltorphin II wasn't blocked by the co-injection (i.c.v.) of [D-Lys(3)]-GHRP-6, indicating that the GHS-R1α isn't on the backward position of δ-opioid receptor. The results suggested that i.c.v. injection of ghrelin initially activated the GHS-R1α, which in turn increased the release of endogenous PENK to activation of OPRD to produce antinociception.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Receptores Opioides delta
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Grelina
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Receptores de Grelina
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Dor Aguda
Limite:
Animals
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Humans
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Male
Idioma:
En
Revista:
Peptides
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
China