8- ( p-sulfophenyl ) theophylline and 3-isobutyl-1-methylxanthine are both adenosine antagonists that can replace the deaminase in permitting beta-adrenergic stimulation of adenylate cyclase , but only the latter also inhibits the phosphodiesterase and causes accumulation of camp .
C0039771
theophylline
C0000096
3-isobutyl-1-methylxanthine