title: In vitro pharmacology of the novel phosphodiesterase type 4 inhibitor, CP-80633.
abstract: We present the in vitro pharmacology of a novel adenosine 3'-5' -cyclic monophosphate-specific phosphodiesterase (PDE) type 4 inhibitor, CP-80633 ((2'S)5-[3-(2' -exobicyclo[2.2.1]-heptyloxy)4-methoxyphenyl] tetrahydro-2(1H)-primidone), which has shown efficacy in phase II clinical trials for atopic dermatitis. CP-80633 inhibits PDE4 isozymes (human lung IC50 = 1.27 microM) in the absence of effects on PDE1, PDE2, PDE3 and PDE5 isozymes (IC50 > 100 microM). It exhibits no significant selectivity for any single cloned PDE4A, B, C or D isoform. CP-80633 inhibits adenosine 3'-5'-cyclic monophosphate hydrolysis in partially purified human peripheral blood monocyte cytosol (IC50 = 3.52 microM), eosinophil membrane (IC50 = 1.10 microM) and T cell membrane (IC50 = 2.28 microM) preparations. Inhibition of eosinophil PDE4 adenosine 3'-5'-cyclic mono-phosphate hydrolysis by CP-80,633 occurs in a noncompetitive manner. Unlike theophylline, CP-80,633 is inactive against ratrain adenosine (A1,A2) receptors. Consistent with its action as a PDE4 inhibitor in whole cells, CP-80633 potentiates PGE1 dependent increases in adenosine 3'-5'-cyclic monophosphate levels in human U937 cells, and in human eosinophils, monocytes and T cells (EC200 approximately 1.0 microM). Consequently, CP-80633 inhibits many inflammatory cell functions including 1) human eosinophil superoxide anion production (IC50 < 0.6 microM), 2 C5a-(IC50 = 0.40 microM) and LTB4-(IC50 = 0.20 microM) mediated guinea pig peritoneal eosinophil chemotaxis and 3) lipopolysac-charide-induced tumor necrosis factor-alpha release from human monocytes (IC50 = 0.219 microM). These data clearly demonstrate that CP-80633 is a selective inhibitor of PDE4 isozymes, and support its potential use as a therapeutic agent for a number of inflammatory and immune disorders.
authors.affiliation: Department of Cancer, Immunology and Infectious Diseases, Pfizer Inc., Groton, Connecticut, USA.
authors.forename: V L
authors.initials: VL
authors.lastname: Cohan
authors.forename: H J
authors.initials: HJ
authors.lastname: Showell
authors.forename: D A
authors.initials: DA
authors.lastname: Fisher
authors.forename: C J
authors.initials: CJ
authors.lastname: Pazoles
authors.forename: J W
authors.initials: JW
authors.lastname: Watson
authors.forename: C R
authors.initials: CR
authors.lastname: Turner
authors.forename: J B
authors.initials: JB
authors.lastname: Cheng
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001667:Binding, Competitive; D001993:Bronchodilator Agents / Q000494:pharmacology*; D003001:Cloning, Molecular; D000242:Cyclic AMP / Q000378:metabolism; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D004804:Eosinophils / Q000187:drug effects*; D006168:Guinea Pigs; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D007700:Kinetics; D009000:Monocytes / Q000187:drug effects*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D010727:Phosphoric Diester Hydrolases; D011744:Pyrimidinones / Q000494:pharmacology*; D011760:Pyrrolidinones / Q000494:pharmacology; D051381:Rats; D018047:Receptors, Purinergic P1 / Q000187:drug effects; D020889:Rolipram; D013379:Substrate Specificity; D013481:Superoxides / Q000378:metabolism; D013806:Theophylline / Q000494:pharmacology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001993:Bronchodilator Agents; C101589:CP 80633; D007527:Isoenzymes; D010726:Phosphodiesterase Inhibitors; D011744:Pyrimidinones; D011760:Pyrrolidinones; D018047:Receptors, Purinergic P1; D013481:Superoxides; D013806:Theophylline; D000242:Cyclic AMP; D010727:Phosphoric Diester Hydrolases; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; C517355:PDE4A protein, human; D020889:Rolipram