Potent effects of novel anti-platelet aggregatory cilostamide analogues on recombinant cyclic nucleotide phosphodiesterase isozyme activity

Biochem Pharmacol. 2000 Feb 15;59(4):347-56. doi: 10.1016/s0006-2952(99)00346-9.


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.

MeSH terms

  • 3',5'-Cyclic-AMP Phosphodiesterases / antagonists & inhibitors*
  • 3',5'-Cyclic-AMP Phosphodiesterases / metabolism
  • Blood Platelets / drug effects
  • Blood Platelets / metabolism
  • Cells, Cultured
  • Cyclic AMP / metabolism
  • Cyclic Nucleotide Phosphodiesterases, Type 1
  • Cyclic Nucleotide Phosphodiesterases, Type 3
  • Humans
  • Isoenzymes / antagonists & inhibitors*
  • Isoenzymes / metabolism
  • Platelet Aggregation / drug effects*
  • Platelet Aggregation Inhibitors / pharmacology*
  • Quinolines / pharmacology
  • Quinolones / pharmacology*
  • Recombinant Proteins / antagonists & inhibitors
  • Semicarbazides / pharmacology
  • Urea / analogs & derivatives
  • Urea / pharmacology


  • Isoenzymes
  • OPC 33536
  • OPC 33540
  • Platelet Aggregation Inhibitors
  • Quinolines
  • Quinolones
  • Recombinant Proteins
  • Semicarbazides
  • cilostamide
  • Urea
  • Cyclic AMP
  • 3',5'-Cyclic-AMP Phosphodiesterases
  • Cyclic Nucleotide Phosphodiesterases, Type 1
  • Cyclic Nucleotide Phosphodiesterases, Type 3
  • PDE3A protein, human
  • OPC 33509