Selective activity of bamifylline on adenosine A1-receptors in rat brain.
The activity of the xanthine derivative bamifylline on central adenosine A1 and A2 receptors has been evaluated with radio-receptor binding in rat brain in comparison with other structure-related compounds. Bamifylline displaced 3H-Cyclo-hexyl-adenosine and 3H-Diethyl-8-phenyl-xanthine with a potency similar to that of 8-phenyl-theophylline, suggesting a high activity on A1-receptor subtype. In contrast, when 3H-N-Ethyl-carboxamido adenosine was used to label A2 adenosine receptors in rat striatum, bamifylline displayed a lower activity comparable to that of enprofylline, an alkyl- xanthine considered a very weak antagonist of adenosine receptors. By calculating for each xanthine derivative its relative potency at A1 and A2 receptors (A2/A1 ratio), bamifylline turned out being the most selective A1 adenosine receptor antagonist so far tested.
Institute of Pharmacological Sciences, University of Milan, Italy.
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Abbracchio
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Cattabeni
D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D051381:Rats; D011983:Receptors, Purinergic / Q000187:drug effects* / Q000378:metabolism; D013806:Theophylline / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D014970:Xanthines / Q000494:pharmacology
D011983:Receptors, Purinergic; D014970:Xanthines; D013806:Theophylline; C034347:enprofylline; C028322:8-phenyltheophylline; C006683:bamifylline