Effects of acute ethanol on opioid peptide release in the central amygdala: an in vivo microdialysis study
Autor: | Christina Gianoulakis, Li Bai, Minh P. Lam, Peter W. Marinelli |
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Rok vydání: | 2008 |
Předmět: |
Male
Photomicrography Met-enkephalin Microdialysis medicine.medical_specialty Enkephalin Enkephalin Methionine Dynorphin Pharmacology Dynorphins Rats Sprague-Dawley chemistry.chemical_compound Internal medicine medicine Animals Opioid peptide Endogenous opioid Dose-Response Relationship Drug Ethanol Central nucleus of the amygdala beta-Endorphin Amygdala Peptide Fragments Rats Endocrinology Opioid Peptides chemistry Peptides Injections Intraperitoneal |
Zdroj: | Psychopharmacology. 201:261-271 |
ISSN: | 1432-2072 0033-3158 |
Popis: | There is experimental evidence that indicates that the endogenous opioid system of the central nucleus of the amygdala (CeA) may mediate some of the reinforcing effects of ethanol. However, the precise interactions of ethanol with the endogenous opioid system at the level of the CeA have not been investigated.The aim of the current study was to investigate the hypothesis that acute systemic ethanol administration will increase the release of endogenous opioid peptides at the level of the CeA in a time- and dose-dependent manner.Rats were implanted with a unilateral guide cannula to aim microdialysis probes at the CeA. Intraperitoneal injections of saline and various doses of ethanol (0.8, 1.6, 2.0, 2.4, and 2.8 g ethanol/kg body weight) were administered to the rats. Dialysate samples were collected at 30-min intervals at distinct time points prior to and following treatment. Radioimmunoassays specific for beta-endorphin, met-enkephalin, and dynorphin A1-8 were used to determine the effect of ethanol on the content of the opioid peptides in the dialysate.We report that the 2.8-g/kg dose of ethanol induced a long-lasting increase in beta-endorphin release from 60 min onwards following administration and, later, an ongoing increase in dynorphin A1-8 release. None of the ethanol doses tested elicited significant changes in dialysate met-enkephalin content compared to the saline treatment.Acute systemic ethanol administration induced a dose- and time-dependent increase in beta-endorphin and dynorphin A1-8 release at the level of the CeA, which may be involved in ethanol consumption. |
Databáze: | OpenAIRE |
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