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Barbiturates are selective antagonists at A\(_1\) adenosine receptors
Zitieren Sie bitte immer diese URN: urn:nbn:de:bvb:20-opus-60187
- Barbiturates in pharmacologically relevant . concentrations inhibit binding of (R)-\(N^6\)-phenylisopropyl[\(^3\)H]adenosine ([\(^3\)H]PIA) to solubilized A\(_1\) adenosine receptors in a concentration-dependent, stereospecific, and competitive manner. K\(_i\) values are similar to those obtained for membrane-bound receptors and are 31 \(\mu\)M for ( ± )-5-(1 ,3-dimethyl)-5-ethylbarbituric acid [( ± )DMBB] and 89 \(\mu\)M for ( ± )-pentobarbital. Kinetic experiments demoostrate that barbiturates compete directly for the binding site of theBarbiturates in pharmacologically relevant . concentrations inhibit binding of (R)-\(N^6\)-phenylisopropyl[\(^3\)H]adenosine ([\(^3\)H]PIA) to solubilized A\(_1\) adenosine receptors in a concentration-dependent, stereospecific, and competitive manner. K\(_i\) values are similar to those obtained for membrane-bound receptors and are 31 \(\mu\)M for ( ± )-5-(1 ,3-dimethyl)-5-ethylbarbituric acid [( ± )DMBB] and 89 \(\mu\)M for ( ± )-pentobarbital. Kinetic experiments demoostrate that barbiturates compete directly for the binding site of the receptor. The inhibition of rat striatal adenylate cyclase by unlabelled (R)-\(N^6\)-phenylisopropyladenosine [(R)-PIA] is antagonized by barbiturates in the same concentrations that inhibit radioligand binding. The Stimulation of adenylate cyclase via A\(_2\) adenosine receptors in membranes from NIE 115 neuroblastoma cells is antagonized only by 10-30 times higher concentrations of barbiturates. lt is concluded that barbiturates are selective antagonists at the A1 receptor subtype. In analogy to the excitatory effects of methylxanthines it is suggested that A\(_1\) adenosine receptor antagonism may convey excitatory properties to barbiturates. Key Words: Adenosine receptors-Barbiturates - Adenylate cyclase-Receptor solubilization-[3H]PIA binding-N1E 115 cells. Lohse M. J. et al. Barbiturates are selective antagonists at A1 adenosine receptors.…
Autor(en): | M. J. Lohse, Karl-Norbert Klotz, K. H. Jakobs, U. Schwabe |
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URN: | urn:nbn:de:bvb:20-opus-60187 |
Dokumentart: | Artikel / Aufsatz in einer Zeitschrift |
Institute der Universität: | Medizinische Fakultät / Institut für Pharmakologie und Toxikologie |
Sprache der Veröffentlichung: | Englisch |
Erscheinungsjahr: | 1985 |
Originalveröffentlichung / Quelle: | Journal of Neumchemistry (1985) 45, 6, 1761-1770. |
Allgemeine fachliche Zuordnung (DDC-Klassifikation): | 6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit |
Normierte Schlagworte (GND): | Toxikologie |
Freie Schlagwort(e): | N1E 115 cells; [3H]PIA binding; adenosine receptors; adenylate cyclase; barbiturates; receptor solubilization |
Datum der Freischaltung: | 05.12.2011 |
Lizenz (Deutsch): | Deutsches Urheberrecht |