title: Calmodulin-dependency of human neutrophil phosphodiesterase.
abstract: A recent study has reported that the phosphodiesterases of human neutrophils are calmodulin-insensitive (Smolen and Geosits, Inflammation 8:193-199, 1984). In the present study, two forms of human neutrophil phosphodiesterase were separated by chromatography on DEAE-52. Peak I phosphodiesterase is activated 2.3-fold by calcium and calmodulin but is not stimulated by either calcium or calmodulin alone. Calmodulin-dependent activation of the phosphodiesterase is blocked by both 20 microM trifluoperazine and 20 microM W-7. Peak II is not stimulated by calmodulin. These findings suggest that calmodulin may play an important role in regulating alterations in cyclic nucleotide metabolism that accompany neutrophil activation.
mesh_terms: D002118:Calcium / Q000494:pharmacology; D002147:Calmodulin / Q000494:pharmacology*; D002848:Chromatography, DEAE-Cellulose / Q000379:methods; D006801:Humans; D009504:Neutrophils / Q000201:enzymology*; D010727:Phosphoric Diester Hydrolases / Q000097:blood* / Q000302:isolation & purification; D013449:Sulfonamides / Q000494:pharmacology; D014268:Trifluoperazine / Q000494:pharmacology
chemical_list: D002147:Calmodulin; D013449:Sulfonamides; D014268:Trifluoperazine; C017967:W 7; D010727:Phosphoric Diester Hydrolases; D002118:Calcium