Presynaptic α2A/D-autoreceptors in the brain cortex of Cercopithecus aethiops
| Autor: | Klaus Starke, A U Trendelenburg, Igor Sutej |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
medicine.medical_specialty
Alpha (ethology) In Vitro Techniques Biology Receptors Presynaptic Cercopithecus aethiops Norepinephrine Radioligand Assay Internal medicine Desipramine Chlorocebus aethiops medicine Animals Receptor Adrenergic alpha-Antagonists Cerebral Cortex Pharmacology Brain cortex General Medicine Adrenergic alpha-2 Receptor Antagonists Electric Stimulation Endocrinology Radioligand binding Autoreceptor Tritium Neuroscience medicine.drug |
| Zdroj: | Naunyn-Schmiedeberg's Archives of Pharmacology. 355:341-346 |
| ISSN: | 0028-1298 |
| Popis: | The existence of presynaptic alpha 2-autoreceptors, and the subtype to which the receptors belong, were studied in the brain cortex from two African green monkeys (Cercopithecus aethiops). Slices of the brain cortex were preincubated with 3H-noradrenaline. The slices were then superfused with medium containing desipramine (1 microM) and stimulated electrically with trains of 72 pulses. 3 Hz. Concentration-response curves of nine alpha-adrenoceptor antagonists were determined. All antagonists enhanced the stimulation-evoked overflow of tritium, i.e. the release of noradrenaline, indicating the existence of presynaptic alpha 2-autoreceptors. The EC30%, values of the antagonists (concentrations that increased the evoked overflow of tritium by 30%) were taken as a measure of affinity for the auto-receptors. The subclassification was based on a comparison of these affinity estimates with affinities for alpha 2A, alpha 2B, alpha 2C and alpha 2D radioligand binding sites and for previously classified alpha 2A- and alpha 2D-autoreceptors. The comparison indicates that the alpha 2-autoreceptors in the brain cortex of Cercopithecus aethiops belong to the genetic alpha 2A/D and not the alpha 2B or alpha 2C subtype. In their pharmacological properties, the autoreceptors are closest to the pharmacological alpha 2D subtype. The results support the notion that alpha 2-autoreceptors belong at least predominantly to the alpha 2A/D subtype of alpha 2-adrenoceptors. |
| Databáze: | OpenAIRE |
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