Further characterization of [3H]ifenprodil binding in rat brain
| Autor: | John L. Neumeyer, Kenji Hashimoto, Edythe D. London, Marianne R. Spada, Charles R. Mantione |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Male
Ruthenium red Arginine Stereochemistry Sigma receptor Dopamine Agents In Vitro Techniques Binding Competitive Guanidines Piperazines chemistry.chemical_compound Piperidines Ifenprodil medicine Animals Receptors sigma Neurotransmitter Uptake Inhibitors Adrenergic alpha-Antagonists Pharmacology Binding Sites Dose-Response Relationship Drug Brain Rats Inbred F344 Rats Spermidine Dizocilpine chemistry NMDA receptor Dizocilpine Maleate Polyamine medicine.drug |
| Zdroj: | European journal of pharmacology. 266(1) |
| ISSN: | 0014-2999 |
| Popis: | The present study was undertaken to characterize [3H]ifenprodil binding in rat brain. [3H]Ifenprodil showed saturable, high-affinity binding at 4 degrees C. Specific binding, defined with 10 microM ifenprodil as a competitor, was inhibited biphasically by the s receptor ligands, GBR 12909, 1,3-di-o-tolylguanidine (DTG), and (+)-3-(3-hydroxyphenyl)-N-propylpiperidine ((+)-3-PPP). At 4 degrees C, 3 microM GBR 12909, which inhibited about 50% of specific binding of [3H]ifenprodil was used to mask sigma receptors. Under these conditions, specific binding of [3H]ifenprodil was inhibited potently by ifenprodil, SL 82.0715, poly(L-arginine), poly(L-lysine), neomycin, ruthenium red, spermine, arcaine and spermidine. In the presence of 3 microM GBR 12909, Zn2+ and Mg2+ partially inhibited specific binding of [3H]ifenprodil at 4 degrees C. In contrast, in the absence of GBR 12909, at 37 degrees C specific binding of [3H]ifenprodil was partially inhibited by Zn2+, but not by Mg2+. The anatomical distribution of [3H]ifenprodil binding at 4 degrees C (GBR 12909 included) in rat brain closely paralleled that of [3H]MK-801 (dizocilpine) binding (r = 0.971, P0.005). Without GBR 12909, specific [3H]ifenprodil binding at 37 degrees C was inhibited potently by sigma ligands. In the presence of 3 microM GBR 12909, [3H]ifenprodil binding at 4 degrees C was highest in synaptosomal and myelin fractions; however, without GBR 12909, [3H]ifenprodil binding at 37 degrees C was highest in microsomal and myelin fractions, consistent with the subcellular distribution of sigma receptors. The results suggest that, in the presence of 3 microM GBR 12909, at 4 degrees C, [3H]ifenprodil binds to sites that are sensitive to polyamines and related compounds; and that without GBR 12909, at 37 degrees C, [3H]ifenprodil interacts with sigma receptors in rat brain. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|