1-methyl-3-isobutylxanthine and theophylline blocked the activation by cyclic gmp of cyclic gmp of cyclic amp hydrolysis , whereas ro 20-1724 ( 4- ( 3-butoxy-4-methoxybenzyl ) -2-imidazolidinone ) , a non-methylxanthine inhibitor of phosphodiesterases , did not alter this effect .
C0000096
1-methyl-3-isobutylxanthine
C0039771
theophylline