title: Potent effects of novel anti-platelet aggregatory cilostamide analogues on recombinant cyclic nucleotide phosphodiesterase isozyme activity.
abstract: The inhibitory potential of novel anti-platelet aggregatory cilostamide analogues on phosphodiesterase (PDE) isozyme activities was investigated with recombinant PDE isozymes expressed in a baculovirus/ Sf9 expression system. The recombinant enzymes (PDE1-PDE5 and PDE7) showed Km values and sensitivities to selective inhibitors similar to those reported previously for native enzymes purified from tissues. The cyclooctylurea derivative OPC-33540 (6-[3-[3-cyclooctyl-3-[(1R*,2R*)-2-hydroxycyclohexyl]ureido]-propoxy]-2(1H)-quinolinone) inhibited recombinant PDE3A (IC50 = 0.32 nM) more potently and selectively than the classical PDE3 inhibitors cilostamide, cilostazol, milrinone, and amrinone. The cyclopropylurea derivative OPC-33509 [(-)-6-[3-[3-cyclopropyl-3-[(1R,2R)-2-hydroxycyclohexyl]ureido]-propoxy]-2(1H)-quinolinone] was less potent (IC50 = 0.10 microM) than OPC-33540, demonstrating that the cyclooctyl moiety was important for a potent inhibitory effect. In platelets, OPC-33540 potentiated cyclic AMP accumulation concentration-dependently in both the absence and the presence of 3 nM prostaglandin E1 (PGE1) (doubling concentrations: 32.5 and 6.2 nM, respectively). OPC-33540 inhibited thrombin-induced platelet aggregation potently (Ic50 = 27.8 nM). The anti-platelet aggregation effect also was stimulated in the presence of 3 nM PGE1 (IC50 = 6.0 nM). There was a good correlation between the IC50 values of PDE3 inhibitors in this study for recombinant PDE3A activity and their IC50 values for thrombin-induced platelet aggregation (r = 0.998). These data demonstrated that OPC-33540 is a highly selective and potent PDE3 inhibitor and a useful probe for identification of the intracellular functions of PDE3.
authors.affiliation: Thrombosis and Vascular Research Laboratory, Otsuka Pharmaceutical Co., Ltd., Tokushima, Japan. t_sudo@research.otsuka.co.jp
authors.forename: T
authors.initials: T
authors.lastname: Sudo
authors.forename: K
authors.initials: K
authors.lastname: Tachibana
authors.forename: K
authors.initials: K
authors.lastname: Toga
authors.forename: S
authors.initials: S
authors.lastname: Tochizawa
authors.forename: Y
authors.initials: Y
authors.lastname: Inoue
authors.forename: Y
authors.initials: Y
authors.lastname: Kimura
authors.forename: H
authors.initials: H
authors.lastname: Hidaka
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D011804:Quinolines / Q000494:pharmacology; D015363:Quinolones / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors; D012663:Semicarbazides / Q000494:pharmacology; D014508:Urea / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D007527:Isoenzymes; C403323:OPC 33536; C403322:OPC 33540; D010975:Platelet Aggregation Inhibitors; D011804:Quinolines; D015363:Quinolones; D011994:Recombinant Proteins; D012663:Semicarbazides; C021294:cilostamide; D014508:Urea; D000242:Cyclic AMP; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3; C517287:PDE3A protein, human; C116725:OPC 33509