Chronic morphine and naltrexone fail to modify mu-opioid receptor mRNA levels in the rat brain.
Brain Res Mol Brain Res
; 45(1): 149-53, 1997 Apr.
Article
em En
| MEDLINE
| ID: mdl-9105683
ABSTRACT
Previous radioligand-binding studies have reported conflicting results concerning the effect of chronic morphine administration on the regulation of mu-opioid receptor (MOR) density. On the other hand, chronic administration of an opioid antagonist, such as naltrexone, has been shown to increase the density of the MOR. In order to determine if the changes in the MOR are associated with alterations in receptor mRNA levels, we investigated MOR gene expression following chronic treatment with morphine and/or naltrexone. MOR mRNA levels, determined by the ribonuclease protection assay (RPA), were unchanged with respect to control during chronic morphine treatment and morphine withdrawal in each of the analysed brain areas. Furthermore, chronic administration of naltrexone did not result in changes of MOR mRNA levels in rat striatum of naive and morphine-dependent rats, suggesting that the up-regulation of the MOR density, at least in this tissue, is not regulated at transcriptional level.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Encéfalo
/
RNA Mensageiro
/
Receptores Opioides mu
/
Morfina
/
Naltrexona
Limite:
Animals
Idioma:
En
Revista:
Brain Res Mol Brain Res
Assunto da revista:
BIOLOGIA MOLECULAR
/
CEREBRO
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Itália