title: Cyclic 3',5'-AMP phosphodiesterase in Physarum polycephalum. I. Chemotaxis toward inhibitors and cyclic nucleotides.
abstract: The effect of several inhibitors of the enzyme cyclic 3',5'-AMP phosphodiesterase as chemoattractants in Physarum polycephalum was examined. Of the compounds tested, 4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone (Roche 20-1724/001) and 1-ethyl-4-(isopropylidinehydrazino)-1H-pyrazolo-(3,4-b)-pyridine-5-carboxylic acid ethyl ester, hydrochloride (Squibb 20009) were the most potent attractants. 3-Isobutyl-1-methyl xanthine, theophylline, and morin (a flavanoid) were moderate attractants and sometimes gave negative chemotaxis at high concentrations. Cyclic 3',5'-AMP was an effective, but not potent attractant. A repellent effect following the positive chemotactic action was sometimes observed with cyclic 3',5'-AMP at concentrations as high as 1 . 10(-2) M. Dibutyryl cyclic AMP appeared to be a somewhat more potent attractant than cyclic 3',5'-AMP. The 8-thiomethyl and 8-bromoderivatives of cyclic AMP, which are poorly hydrolyzed by the phosphodiesterase, were not attractants in Physarum. Possible participation of cyclic 3',5'-AMP in the directional movement in P. polycephalum is discussed.
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism*; D002633:Chemotaxis / Q000187:drug effects*; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology; D009712:Nucleotides, Cyclic / Q000494:pharmacology*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D010804:Physarum / Q000187:drug effects / Q000201:enzymology*; D013329:Structure-Activity Relationship
chemical_list: D009712:Nucleotides, Cyclic; D010726:Phosphodiesterase Inhibitors; D000242:Cyclic AMP; D015105:3',5'-Cyclic-AMP Phosphodiesterases