Phosphodiesterase Inhibitors3',5'-Cyclic-AMP PhosphodiesterasesCyclic Nucleotide Phosphodiesterases, Type 4Phosphoric Diester HydrolasesCyclic Nucleotide Phosphodiesterases, Type 33',5'-Cyclic-GMP PhosphodiesterasesRolipram1-Methyl-3-isobutylxanthineCyclic Nucleotide Phosphodiesterases, Type 1Cyclic Nucleotide Phosphodiesterases, Type 2PurinonesCyclic AMP4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinoneCyclic GMPCyclic Nucleotide Phosphodiesterases, Type 52',3'-Cyclic-Nucleotide PhosphodiesterasesPhosphodiesterase 3 InhibitorsPhosphodiesterase 4 InhibitorsTheophyllineMilrinonePhosphodiesterase 5 InhibitorsPhosphodiesterase IPyrrolidinonesCyclic Nucleotide Phosphodiesterases, Type 7PapaverineNucleotides, CyclicColforsinSulfonesAdenylate CyclaseXanthinesBucladesinePentoxifylline8-Bromo Cyclic Adenosine MonophosphatePurinesCyclic AMP-Dependent Protein KinasesIsoproterenolVinca AlkaloidsPyridazinesKineticsIsoenzymesPhosphorus-Oxygen LyasesSecond Messenger SystemsCyclic GMP-Dependent Protein KinasesGuanylate CyclaseEnoximoneDose-Response Relationship, DrugCalciumPiperazinesCyclic Nucleotide Phosphodiesterases, Type 6DipyridamoleEnzyme ActivationAmrinoneAminophyllinePyrophosphatasesBufo bufoCells, CulturedIsoquinolinesSignal TransductionGlycerylphosphorylcholinePhotoreceptor CellsDibutyryl Cyclic GMPHydrolysisCattleNitric OxideGuinea PigsMolecular Sequence DataEnzyme InhibitorsCalmodulinErectile DysfunctionAlprostadilReceptors, Adrenergic, betaPhthalazinesVasodilator AgentsPyridonesThionucleotidesAmino Acid SequenceAdenosinePhenylisopropyladenosineRats, Inbred StrainsCyclic P-OxidesCatalytic DomainMyocardiumProstaglandins IPenile ErectionRats, WistarRats, Sprague-DawleyStimulation, ChemicalCarbolinesProstaglandins E, SyntheticTransducinNitroprussideTetrazolesSubstrate SpecificityImidazolesCholera ToxinTime FactorsNicotinic AcidsIloprostAdenine NucleotidesPhosphorylation