1-Methyl-3-isobutylxanthine 4 4 (3 butoxy 4 methoxybenzyl) 2 imidazolidinone 4 Amylomyces rouxii 4 Cyclic AMP 4 Mucor 4 Support, Non-U.S. Gov't 4 amrinone 4 article 4 cilostamide 4 cilostazol 4 dipyridamole 4 etazolate 4 imazodan 4 isobutylmethylxanthine 4 milrinone 4 mucor 4 nonhuman 4 papaverine 4 phosphodiesterase inhibitor 4 rolipram 4 sq 65442 4 theophylline 4 unclassified drug 4 1 ethyl 4 hydrazino 1h pyrazolo[3,4 b]pyridine 5 carboxylic acid ethyl ester 3 3',5'-Cyclic-Nucleotide Phosphodiesterase 3 4,5 dihydro 6 [4 (1h imidazol 1 yl)phenyl] 5 methyl 3(2h) pyridazinone 3 6 [4 (3 methylureido)phenyl] 3(2h) pyridazinone 3 Centrifugation, Density Gradient 3 Cyclic GMP 3 Dipyridamole 3