EnoximonePhosphodiesterase Inhibitors3',5'-Cyclic-AMP Phosphodiesterases1-Methyl-3-isobutylxanthineRolipramPhosphoric Diester HydrolasesPurinones4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinoneCyclic AMP3',5'-Cyclic-GMP PhosphodiesterasesCyclic Nucleotide Phosphodiesterases, Type 4Cyclic Nucleotide Phosphodiesterases, Type 3TheophyllinePhosphodiesterase 3 InhibitorsPhosphodiesterase 4 InhibitorsCyclic GMPMilrinonePhosphodiesterase 5 InhibitorsPapaverinePyrrolidinonesCyclic Nucleotide Phosphodiesterases, Type 5Phosphodiesterase ICyclic Nucleotide Phosphodiesterases, Type 12',3'-Cyclic-Nucleotide PhosphodiesterasesColforsinPentoxifyllineBucladesineSulfonesXanthinesCardiotonic Agents8-Bromo Cyclic Adenosine MonophosphateNucleotides, CyclicPyridazinesAdenylate CyclasePurines