title: KF19514, a phosphodieterase 4 and 1 inhibitor, inhibits PAF-induced lung inflammatory responses by inhaled administration in guinea pigs.
abstract: Phosphodiesterase (PDE) 4 inhibitors are well known for their inhibitory effect on bronchoconstriction and inflammation and may be promising anti-asthma drugs. Platelet-activating factor (PAF) has been proposed as an inflammatory mediator to be relevant to asthma. It causes bronchoconstriction, airway microvascular leakage, inflammatory cell accumulation in the lung and hyperresponsiveness. In this study, we therefore have investigated the anti-asthmatic effects of the inhaled KF19514 [5-phenyl-3'-(3-pyridyl)methyl-3H-imidazo(4,5-c)(1,8) naphthyridin-4(5H)-one], a PDE 4 and 1 inhibitor, on PAF-induced lung inflammatory responses in guinea pigs. The inhaled KF19514 (0.0001-0.01%) significantly inhibited PAF-induced eosinophil and neutrophil accumulation into the airway and hyperresponsiveness in guinea pigs. The IC50 value of KF19514 against eosinophil accumulation was 14.8 microM (0.00063%). Moreover, the effect of KF19514 on the electrical field stimulation-induced bronchial contraction was examined using the main bronchi of guinea pigs in vitro. KF19514 inhibited both cholinergic and tachykininergic contraction and, in particular, produced a potent inhibitory effect on tachykininergic contraction (IC50 = 0.49 microM). The mechanism by which KF19514 inhibited the PAF-induced hyperresponsiveness may in part be the suppression of the tachykinin release. Based on these results, it was demonstrated that the inhaled KF19514 might have a significant potential effect on the inflammatory cell accumulation and hyperresponsiveness induced by PAF.
authors.affiliation: Pharmaceutical Research Laboratories, Kyowa Hakko Kogyo, Shizuoka, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Manabe
authors.forename: K
authors.initials: K
authors.lastname: Akuta
authors.forename: K
authors.initials: K
authors.lastname: Okamura
authors.forename: K
authors.initials: K
authors.lastname: Ohmori
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors; D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000037:antagonists & inhibitors; D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001249:Asthma / Q000139:chemically induced / Q000188:drug therapy*; D001980:Bronchi / Q000187:drug effects; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D016084:Bronchoconstriction / Q000187:drug effects; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D004804:Eosinophils / Q000187:drug effects; D006168:Guinea Pigs; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009287:Naphthyridines / Q000627:therapeutic use*; D015288:Neurokinin A / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects; D010726:Phosphodiesterase Inhibitors / Q000627:therapeutic use*; D010727:Phosphoric Diester Hydrolases; D010972:Platelet Activating Factor / Q000494:pharmacology*; D011760:Pyrrolidinones / Q000494:pharmacology; D012138:Respiratory Therapy; D020889:Rolipram; D013373:Substance P / Q000494:pharmacology
chemical_list: D001993:Bronchodilator Agents; C106878:KF 19514; D009287:Naphthyridines; D010726:Phosphodiesterase Inhibitors; D010972:Platelet Activating Factor; D011760:Pyrrolidinones; D013373:Substance P; D015288:Neurokinin A; D010727:Phosphoric Diester Hydrolases; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D020889:Rolipram; D000109:Acetylcholine