Adenosine Deaminase InhibitorsAdenineCyclic Nucleotide Phosphodiesterases, Type 2TubercidinAdenosine KinaseAdenosineDideoxyadenosineAdenosine DeaminasePhosphodiesterase InhibitorsInosineStage-Specific Embryonic AntigensCyclic Nucleotide Phosphodiesterases, Type 1MilrinoneDeoxyadenosinesHypoxanthine3',5'-Cyclic-AMP PhosphodiesterasesXanthinesTheophyllineDipyridamoleEnzyme InhibitorsCyclic AMPRats, Sprague-DawleyCells, Cultured