Inhibition of platelet cyclic 3',5'-adenosine-monophosphate phosphodiesterases by pentifylline

Pentifylline (1-hexyl-3,7-dimethylxanthine equals SK 7, the main active principle in Cosaldon) inhibits the soluble and the particulate cyclic AMP phosphodiesterases (PDE I and PDE II) from bovine platelets. I50 PDE I equals 2.0 x 10(-3)M; I50 PDE II equals 8.1 x 10(-4)M. The type of inhibition of both PDE's was non-competitive.