RolipramCyclic Nucleotide Phosphodiesterases, Type 4Phosphodiesterase InhibitorsPyrrolidinones3',5'-Cyclic-AMP PhosphodiesterasesCyclic Nucleotide Phosphodiesterases, Type 3PurinonesCyclic AMP4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinoneCyclic Nucleotide Phosphodiesterases, Type 1Phosphoric Diester HydrolasesPyridazines1-Methyl-3-isobutylxanthine