Identification of the opiosd receptor types mediating β-endorphin-induced alterations in dopamine release in the nucleus accumbens
| Autor: | Toni S. Shippenberg, Rainer Spanagel, Albert Herz |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Male
Microdialysis medicine.medical_specialty medicine.drug_class Dopamine Narcotic Antagonists Nucleus accumbens Nucleus Accumbens chemistry.chemical_compound Opioid receptor In vivo Internal medicine medicine Animals Biogenic Monoamines Receptor Chromatography High Pressure Liquid Injections Intraventricular Brain Chemistry Pharmacology Analgesics Chemistry beta-Endorphin Homovanillic acid Rats Inbred Strains Enkephalins Enkephalin Ala(2)-MePhe(4)-Gly(5) Rats Endocrinology Receptors Opioid Liberation Enkephalin D-Penicillamine (2 5) Somatostatin Dialysis hormones hormone substitutes and hormone antagonists Enkephalin Leucine medicine.drug |
| Zdroj: | European Journal of Pharmacology. 190:177-184 |
| ISSN: | 0014-2999 |
| DOI: | 10.1016/0014-2999(90)94124-g |
| Popis: | In the present study we used in vivo microdialysis to examine the influence of beta-endorphin on dopamine (DA) release in the nucleus accumbens of anesthetized rats and to identify the opioid receptor types mediating its effects. Microdialysis probes were inserted into the nucleus accumbens and perfusates were analysed for DA and its metabolites, dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), using a reversed phase HPLC system with electrochemical detection for separation and quantification. Intracerebroventricular (i.c.v.) administration of beta-endorphin resulted in a dose-dependent increase in DA and its metabolites. Pretreatment with the selective delta-antagonist ICI 174,864 significantly attenuated the beta-endorphin-induced increase in DA release and metabolism whereas pretreatment with the selective mu-antagonist CTOP resulted abolition of the beta-endorphin effect. These data demonstrate that the blockade of either mu- or delta-opioid receptors is sufficient to antagonize the stimulatory effects of beta-endorphin on DA release and metabolism. As such, these findings suggest that the concomitant activation of both mu- and delta-receptors underlies the effects of beta-endorphin on DA release in the nucleus accumbens. |
| Databáze: | OpenAIRE |
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