1-Allyl-3,7-dimethyl-8-phenylxanthine is an antagonist of the A1 adenosine receptor. 1-Allyl-3,7-dimethyl-8-phenylxanthine is described to block increases in intracellular Ca2+ concentration produced by the A1 receptor agonist 2-chloro-N6-cyclopentyl-adenosine but did not antagonize increases produced by the A2 agonist 2-p-(2-carboxy-ethyl) phenethylamino-5'-N-ethylcarboxyamide adenosine hydrochloride or the A3 agonist N6-2-(4-Aminophenyl)ethyladenosine (sc-253170).
