ESTRADIOL AND PROGESTERONE ALTER ETHANOL-INDUCED EFFECTS ON MU-OPIOIDRECEPTORS IN SPECIFIC BRAIN-REGIONS OF OVARIECTOMIZED RATS

Citation
A. Carter et Mri. Soliman, ESTRADIOL AND PROGESTERONE ALTER ETHANOL-INDUCED EFFECTS ON MU-OPIOIDRECEPTORS IN SPECIFIC BRAIN-REGIONS OF OVARIECTOMIZED RATS, Life sciences, 62(2), 1997, pp. 93-101
Citations number
29
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biology,"Medicine, Research & Experimental","Pharmacology & Pharmacy
Journal title
ISSN journal
0024-3205
Volume
62
Issue
2
Year of publication
1997
Pages
93 - 101
Database
ISI
SICI code
0024-3205(1997)62:2<93:EAPAEE>2.0.ZU;2-2
Abstract
This study was conducted to evaluate the effects of estradiol and prog esterone on ethanol-induced alterations of mu-opioid receptor binding kinetics in specific brain regions. Female ovariectomized rats were in jected with ethanol (3 g/kg, i.p.), estradiol (50 mu g/kg, s.c.) and/o r progesterone (5 mg/kg, s.c.), or ethanol plus estradiol and/or proge sterone daily for 7 days. Control animals received saline and olive oi l. Brains were immediately removed and the cortex, hippocampus, hypoth alamus, and midbrain were dissected and assayed for mu-opioid receptor binding kinetics. In the hypothalamus, ethanol alone and in combinati on with estradiol and/or progesterone significantly decreased B-max. E thanol alone also decreased B-max in the midbrain and cortex. When adm inistered with estradiol only, ethanol increased B-max and K-d in the hippocampus. The administration of estradiol alone and progesterone al one decreased B, in the hypothalamus, while not affecting B-max in any of the other brain regions. However, when estradiol and progesterone were combined, B-max, as well as K-d, increased in the cortex. Progest erone alone and in combination with estradiol also increased K-d in th e midbrain. In addition, K-d significantly increased following adminis tration of ethanol in combination with either of the hormones, or both , in the midbrain and cortex. These results clearly indicate that the female hormones modulate the effects of ethanol on binding kinetics of mu-opioid receptors in specific brain regions. The present findings m ay in part explain sex differences in alcohol effects.