Chronic haloperidol does not alter agonist affinity for dopamine receptors in vitro
| Autor: | Jack W. Schweitzer, Emanuel Meller, Menek Goldstein, Karen Bohmaker, Arnold J. Friedhoff |
|---|---|
| Rok vydání: | 1985 |
| Předmět: |
Male
Agonist medicine.medical_specialty Spiperone Indoles Apomorphine medicine.drug_class Pharmacology Binding Competitive Dopamine agonist Receptors Dopamine Internal medicine Dopamine receptor D2 medicine Haloperidol Animals Potency Receptors Dopamine D2 Chemistry Dopaminergic Rats Inbred Strains Corpus Striatum Rats Endocrinology Dopamine receptor medicine.drug |
| Zdroj: | European Journal of Pharmacology. 109:389-394 |
| ISSN: | 0014-2999 |
| DOI: | 10.1016/0014-2999(85)90400-5 |
| Popis: | Agonist competition for [3H]spiperone binding to striatal dopamine D2 receptors was studied in rats rendered supersensitive by chronic treatment with haloperidol. The classical dopamine agonist (-)-N-n-propylnorapomorphine displaced [3H]spiperone biphasically, with IC50 values of 0.5 and 140 nM for the high and low affinity components, respectively. Neither the relative density nor the affinity of either site for (-)-N-propylnorapomorphine was affected by chronic haloperidol treatment. On the other hand, the novel agonist EMD 23 448 displaced [3H]spiperone monophasically. Although this agent only displays potent dopaminergic agonism in supersensitive animals, chronic treatment with haloperidol likewise did not alter the affinity of this drug for [3H]spiperone binding sites. The results suggest that the enhanced in vivo potency of certain agonists in supersensitive animals is probably not mediated by changes in D2 receptor affinity. |
| Databáze: | OpenAIRE |
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