dinoprost and seratrodast

A dry powder inhaler of KP-496 is currently in clinical development in Japan as an anti-asthmatic agent. The aim of this study was to evaluate the in vitro pharmacological profile of KP-496.. The antagonistic activities of KP-496 for leukotriene (LT) D(4) and thromboxane (TX) A(2) receptors were examined using the LTD(4)- and U46619-induced contractions of the isolated guinea pig trachea. The selectivity of KP-496 was examined using various agonist-induced contractions in the isolated guinea pig trachea.. KP-496 produced parallel rightward shifts of the LTD(4) and U46619 concentration-response curves in a concentration-dependent manner. Schild plot analyses of the antagonistic activities of KP-496 demonstrated that it is a competitive antagonist for LTD(4) and TXA(2) receptors with pA(2) values of 8.64 and 8.23, respectively. The LTD(4) antagonistic activity of KP-496 was comparable to that of pranlukast and zafirlukast but was more potent than that of montelukast. The TXA(2) antagonistic activity of KP-496 was comparable to that of seratrodast. KP-496 and seratrodast also inhibited the prostaglandin (PG) D(2)- and PGF(2alpha)-induced contractions of the isolated guinea pig trachea. KP-496 had no effect on the histamine-, acetylcholine-, serotonin- and substance P-induced contractions of the isolated guinea pig trachea.. These results indicate that KP-496 is a selective dual antagonist for LTD(4) and TXA(2) receptors. LTD(4) and TXA(2) play important roles in asthma, and antagonists for these mediators are being used for the treatment of asthma. Thus, KP-496 is expected to become a novel potent therapeutic agent for asthma.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Acetates; Acetylcholine; Albuterol; Animals; Atropine; Benzoquinones; Carbachol; Chromones; Cyclopropanes; Dinoprost; Drug Evaluation, Preclinical; Guinea Pigs; Heptanoic Acids; Histamine; In Vitro Techniques; Indoles; Indomethacin; Ketanserin; Ketotifen; Leukotriene Antagonists; Leukotriene D4; Male; Muscle Contraction; Muscle, Smooth; Phenylcarbamates; Powders; Procaterol; Prostaglandin Antagonists; Prostaglandin D2; Quinolines; Receptors, Thromboxane A2, Prostaglandin H2; Serotonin; Substance P; Sulfides; Sulfonamides; Tosyl Compounds; Trachea; Tryptophan

The airway of asthmatic patients is hyperresponsive to various stimuli in vivo. There are, however, only a few reports that compared the in vivo responsiveness of asthmatic patients and non-asthmatic subjects to those of lung parenchyma in vitro.. To compare the contractile response, release of various chemical mediators, and responsiveness to drugs in samples of lung parenchyma excised from asthma patients with those of non-asthmatic subjects.. Human lung parenchymal strips were subjected to passive sensitization with sera of 5+ RAST titer to mites. The strip was suspended in a magnus bath containing a buffer solution. Parenchymal contraction was induced by PGF2 alpha. After washing, the baseline concentrations of thromboxane B2 (TXB2), leukotriene (LT), and histamine were measured in each bath and then contraction was induced by the addition of a mite antigen. The concentrations of TXB2, LT, and histamine were measured after contraction. The inhibitory effects of TXA2 synthetase inhibitor (DP-1904) and TXA2 receptor antagonist (AA-2414) were also evaluated in both tissue samples.. There were no significant differences between lung parenchymal tissues of asthmatic and non-asthmatic patients with regard to PGF2 alpha-induced contraction, antigen-induced contraction, release of chemical mediators, and the response to drugs.. Unlike the response in vivo, there are no differences in the response to stimuli in vitro between lung parenchymal tissues of asthmatic and non-asthmatic patients.

Topics: Aged; Airway Resistance; Animals; Antigens; Ascaris; Asthma; Benzoquinones; Dinoprost; Dogs; Female; Heptanoic Acids; Histamine Release; Humans; Immune Sera; Immunization, Passive; Leukotrienes; Lung; Male; Middle Aged; Mites; Muscle Contraction; Muscle, Smooth; Radioallergosorbent Test; Smoking; Thromboxane B2; Thromboxane-A Synthase

The effects of a novel TXA2 receptor antagonist, AA-2414 [(+-)-7-(3,5,6-trimethyl-1,4-benzoquinone-2-yl)-7-phenyl-heptanoic acid], on U-46619-, PGD2- and 9 alpha, 11 beta-PGF2 alpha-induced contractions of isolated guinea pig tracheas and human bronchi were investigated. AA-2414 competitively inhibited the contractile responses of both human and guinea pig preparations induced by U-46619 with similar pA2 values (7.7 and 7.6, respectively). In addition, the compound also inhibited the contractions of both preparations caused by PGD2 and 9 alpha, 11 beta-PGF2 alpha, the IC50 values of which were 1.2 x 10(-7) and 1.8 x 10(-7) M in guinea pig tracheas and 2.8 x 10(-8) and 8.5 x 10(-8) M in human bronchi. These results suggest that AA-2414 may be a therapeutically useful drug for bronchial asthma.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Animals; Benzoquinones; Bronchi; Dinoprost; Guinea Pigs; Heptanoic Acids; Humans; In Vitro Techniques; Male; Muscle Contraction; Muscle, Smooth; Prostaglandin D2; Prostaglandin Endoperoxides, Synthetic; Quinones; Receptors, Thromboxane; Thromboxane A2; Trachea

AA-2414, (+/-)-7-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-7-phenylheptanoi c acid, inhibited the aggregation of guinea pig platelets induced by a prostaglandin endoperoxide (PGH2) analogue, U-44069 and the specific binding of another analogue, [3H]U-46619 to washed guinea pig platelets with IC50 values of 3.1 x 10(-7) and 8.2 x 10(-9) M, respectively. AA-2414 competitively inhibited the contraction of rabbit aorta and pig coronary arteries induced by U-44069 with pA2 values of 8.3 and 9.0, respectively. AA-2414 also inhibited the contraction of rabbit aorta induced by PGF2 alpha (pA2: 7.8) and the contraction of pig coronary arteries induced by PGF2 alpha, PGD2 and 9 alpha,11 beta-PGF2 with pA2 values of 7.8, 8.6 and 7.8, respectively. But, AA-2414 had no effect on the antiaggregatory effect of PGD2 on the aggregation of guinea pig platelets. In experiments with guinea pigs ex vivo, AA-2414 (0.1-1 mg/kg, p.o.) dose-dependently inhibited the platelet aggregation induced by U-44069; the inhibition at a dose of 1 mg/kg was 100% at 1 hr and was 89% even at 24 hr after the administration. The thromboxane (TX) A2/PGH2 receptor antagonistic action of AA-2414 was stereospecific. These results show that AA-2414 is a potent, orally active and long acting TXA2/PGH2 receptor antagonist. In addition, AA-2414 has PGF2 alpha, PGD2 and 9 alpha,11 beta-PGF2 antagonistic effects.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Animals; Benzoquinones; Blood Platelets; Dinoprost; Eicosanoids; Epoprostenol; Guinea Pigs; Heptanoic Acids; In Vitro Techniques; Male; Muscle, Smooth, Vascular; Platelet Aggregation; Platelet Aggregation Inhibitors; Prostaglandin D2; Prostaglandin Endoperoxides, Synthetic; Quinones; Rabbits; Receptors, Prostaglandin; Receptors, Thromboxane; Stereoisomerism; Swine