Phosphodiesterase InhibitorsAdenosine1-Methyl-3-isobutylxanthine3',5'-Cyclic-AMP PhosphodiesterasesRolipramPhosphoric Diester HydrolasesPurinonesCyclic AMP4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone3',5'-Cyclic-GMP PhosphodiesterasesCyclic Nucleotide Phosphodiesterases, Type 4TheophyllineReceptor, Adenosine A2APhosphodiesterase 3 InhibitorsPhosphodiesterase 4 InhibitorsCyclic GMPMilrinoneReceptor, Adenosine A1Cyclic Nucleotide Phosphodiesterases, Type 3Phosphodiesterase 5 InhibitorsPapaverineXanthinesPyrrolidinonesAdenosine DeaminaseCyclic Nucleotide Phosphodiesterases, Type 5Phosphodiesterase IReceptor, Adenosine A3ColforsinCyclic Nucleotide Phosphodiesterases, Type 12',3'-Cyclic-Nucleotide PhosphodiesterasesBucladesinePentoxifyllineReceptor, Adenosine A2BAdenosine Kinase8-Bromo Cyclic Adenosine MonophosphateReceptors, Purinergic P1PurinesSulfonesAdenylate CyclaseNucleotides, CyclicPyridazinesReceptors, Adenosine A2Adenosine A2 Receptor AgonistsAdenosine A2 Receptor AntagonistsIsoproterenolPurinergic P1 Receptor AntagonistsAdenosine A1 Receptor AntagonistsPhenylisopropyladenosineAdenosine-5'-(N-ethylcarboxamide)Adenosine A1 Receptor AgonistsAminophyllineEnoximoneKineticsDose-Response Relationship, DrugVinca AlkaloidsDipyridamoleAdenosine MonophosphateCyclic AMP-Dependent Protein KinasesCalciumAmrinonePurinergic P1 Receptor AgonistsBufo bufoCyclic Nucleotide Phosphodiesterases, Type 2Dibutyryl Cyclic GMPPhotoreceptor CellsCyclic Nucleotide Phosphodiesterases, Type 6Cells, CulturedGuinea PigsPiperazinesThionucleotidesVasodilator AgentsEnzyme ActivationAlprostadilGuanylate CyclaseTriazinesErectile DysfunctionPhthalazinesPyridonesStimulation, ChemicalAdenine NucleotidesSecond Messenger SystemsRats, Inbred StrainsNitric OxidePenile ErectionCyclic Nucleotide Phosphodiesterases, Type 7CattleIsoquinolinesProstaglandins IReceptors, PurinergicCyclic GMP-Dependent Protein KinasesAdenineNitroprussideSignal TransductionCholera ToxinRats, WistarAdenosine A3 Receptor AntagonistsRats, Sprague-DawleyProstaglandins E, SyntheticEnzyme InhibitorsCaffeine