Estrogen-dependent alterations in D2/D3-induced G protein activation in cocaine-sensitized female rats.
J Neurochem
; 86(2): 405-12, 2003 Jul.
Article
em En
| MEDLINE
| ID: mdl-12871581
Estrogen potentiates behavioral sensitization to cocaine in the female rat by mechanisms that remain undetermined. In this study, functional receptor autoradiography was used to investigate estrogen modulation of D2/D3 receptor-induced G protein activation in components of the reward pathway of female rats treated acutely and repeatedly with cocaine. Rats were ovariectomized and given an empty (OVX group) or estradiol benzoate-filled (OVX-EB group) implant. After a week, animals received a daily saline or cocaine injection (15 mg/kg, i.p.) for 5 days, and again on day 13. Animals were killed, and brains were removed and cryosectioned. D2/D3-stimulated [35S]guanosine 5'-(gamma-thio) triphosphate (GTPgammaS) binding was assessed in the cingulate cortex area 2 (Cg2), striatum (STR), nucleus accumbens (NAc) and ventral tegmental area (VTA). OVX-EB rats showed more [35S]GTPgammaS binding in the Cg2 and lower binding in the VTA than OVX rats; in the VTA this effect was reversed by a single cocaine injection. Repeated cocaine administration had opposite effects in OVX and OVX-EB rats. [35S]GTPgammaS binding was decreased in the Cg2, NAc and STR of OVX-EB rats, and increased in OVX rats. The present results support the hypothesis that cocaine-induced changes in D2/D3 receptor activation are regulated by estrogen. These data suggest that changes in D2/D3 receptor function represent one mechanism by which estrogen regulates behavioral sensitization to cocaine.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Receptores de Dopamina D2
/
Cocaína
/
Proteínas de Ligação ao GTP
/
Estradiol
/
Estrogênios
Limite:
Animals
Idioma:
En
Revista:
J Neurochem
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Porto Rico
País de publicação:
Reino Unido