ozagrel and seratrodast

Topics: Adult; Aged; Aged, 80 and over; Anti-Allergic Agents; Asthma; Benzoquinones; Chemical and Drug Induced Liver Injury; Enzyme Inhibitors; Female; Heptanoic Acids; Humans; Lung Diseases, Interstitial; Male; Methacrylates; Middle Aged; Receptors, Thromboxane A2, Prostaglandin H2; Thromboxane-A Synthase

COPD (Chronic Obstructive Pulmonary Disease) and bronchial asthma are two severe lung diseases which represent a major problem of world public health. Leukotrienes and prostanoids play an important role in the pathogenesis of pulmonary diseases. Prostanoids: prostaglandins (PGs) and thromboxane A2 (TXA2), the cyclooxygenase metabolites of arachidonic acid are implicated in the inflammatory cascade that occurs in asthmatic airways. Recently, the roles played by isoprostanes or prostaglandin-like compounds nonenzymatically generated via peroxidation of membrane phospholipids by reactive oxygen species, in particular F2-isoprostanes, in pulmonary pathophysiology have been highlighted. This article aims to provide an overview of the role of prostanoids and isoprostanes in the pathogenesis of COPD and asthma and to discuss the pharmacological strategies developed in prevention and/or treatment of these pathologies.

Topics: Animals; Asthma; Benzoquinones; Carbazoles; Enzyme Inhibitors; F2-Isoprostanes; Heptanoic Acids; Humans; Methacrylates; Prostaglandin Antagonists; Prostaglandin D2; Pulmonary Disease, Chronic Obstructive; Randomized Controlled Trials as Topic; Receptors, Immunologic; Receptors, Prostaglandin; Receptors, Thromboxane A2, Prostaglandin H2; Sulfonamides; Thromboxane A2; Thromboxane-A Synthase

Bronchial asthma is a disease defined by reversible airway obstruction, bronchial hyperresponsiveness and inflammation. In addition to histamine and acetylcholine, recent studies have emphasized the role of arachidonic acid metabolites (leukotrienes, prostaglandins and thromboxane A(2)) in the pathogenesis of asthma. Among these mediators, thromboxane A(2) (TXA(2)) has attracted attention as an important mediator in the pathophysiology of asthma because of its potent bronchoconstrictive activity. Thromboxane A(2) is believed to be involved not only in late asthmatic responses but also in bronchial hyperresponsiveness, a typical feature of asthma. Strategies for inhibition of TXA(2) include TXA(2) receptor antagonism and thromboxane synthase inhibition. Results of double-blind, placebo-controlled clinical trials have proven the efficacies of the thromboxane receptor antagonist seratrodast and the thromboxane synthase inhibitor ozagrel in the treatment of patients with asthma. Seratrodast and ozagrel are available in Japan for the treatment of asthma. Ramatroban, another thromboxane receptor antagonist, is currently under phase III clinical evaluation in Europe and Japan for the treatment of asthma. The pharmacological profiles of the thromboxane modulators may be improved by combination with leukotriene D(4) receptor antagonists. A multi-pathway inhibitory agent such as YM 158, which is a novel orally active dual antagonist for leukotriene D(4) and thromboxane A(2 )receptors, may have potent therapeutic effects in the treatment of bronchial asthma. Large scale clinical trials are necessary to further define the role of thromboxane modulators in the treatment of patients with asthma.

Topics: Anti-Asthmatic Agents; Asthma; Benzoquinones; Carbazoles; Heptanoic Acids; Humans; Methacrylates; Molecular Structure; Receptors, Thromboxane; Sulfonamides; Thromboxane A2; Thromboxane-A Synthase

Thromboxane A2 (TxA2) plays an important role in asthma. TxA2 are newly generated after cellular activation and are produced by not only platelets but also eosinophils, basophils, alveolar macrophages, and neutrophils. Pharmacological actions of TxA2 include potent bronchoconstriction, increased microvascular leakage, impairment of mucociliary clearance, and induction of airway hyperresponsiveness. Recent study demonstrated that TxA2 receptor antagonist decreased the number of eosinophils in bronchial biopsy specimens, suggesting that this type of agent possesses anti-inflammatory actions in asthma. Furthermore, addition of TxA2 synthase inhibitor significantly increased the PEF values in the persistent asthmatic patients despite the treatment with moderate-dose of inhaled corticosteroids. Therefore, these results suggest that TxA2 synthase inhibitor and receptor antagonist are useful for the treatment with symptomatic patients who had already been treated with inhaled corticosteroids.

Topics: Asthma; Benzoquinones; Bronchi; Bronchial Hyperreactivity; Eosinophils; Heptanoic Acids; Humans; Methacrylates; Practice Guidelines as Topic; Receptors, Thromboxane; Thromboxane A2; Thromboxane-A Synthase

Leukotriene (LT) and thromboxane A2 (TXA2) receptor antagonists have been used in the treatment of asthma.. We examined the effects of an LT receptor antagonist, TXA2 receptor antagonist, and TXA2 synthetase inhibitor on bronchoprovocation test (BPT) in patients with mild-to-moderate atopic asthma.. BPT was performed four times in each of six asthmatics. Development of the immediate asthmatic reaction (IAR) and late asthmatic reaction (LAR) was confirmed on the first BPT (BPT1). After a 7-day washout period, an LT receptor antagonist (pranlukast, 450 mg/d), TXA2 receptor antagonist (seratrodast, 80 mg/d), or TXA2 synthetase inhibitor (ozagrel, 800 mg/d) was administered orally over 7 days at random using a cross-over method (BPT2-4). Blood levels of LTB4, LTC4, LTD4, 11-dehydrothromboxane B2, eosinophil cationic protein, and histamine were measured at reaction phases of pre-BPT, IAR, and LAR.. Administration of pranlukast suppressed IAR by 80.5% (p < 0.0001) and LAR by 54.6% (p = 0.0391). Ozagrel significantly suppressed IAR by 39.5% (p = 0.0413), but the fall in FEV1 was >20% (21.56+/-4.173%). Seratrodast did not suppress IAR or LAR. Blood levels of chemical mediators did not correlate with the suppressive effects of the tested drugs.. The LT receptor antagonist was considered to be the most effective. LT might play a more important role in the pathogenesis of asthma than TXA2. Our data showed that measurement of blood levels of chemical mediators is not useful in identifying the pathogenic mechanisms of asthma.

Topics: Administration, Oral; Adult; Anti-Asthmatic Agents; Antigens; Asthma; Benzoquinones; Blood Proteins; Bronchial Provocation Tests; Bronchoconstriction; Chromones; Cross-Over Studies; Eosinophil Granule Proteins; Female; Follow-Up Studies; Heptanoic Acids; Histamine; Humans; Leukotriene Antagonists; Male; Membrane Proteins; Methacrylates; Receptors, Leukotriene; Receptors, Thromboxane; Ribonucleases; Thromboxane B2; Thromboxane-A Synthase; Treatment Outcome

Remote hind limb preconditioning (RIPC) is a protective strategy in which short episodes of ischemia and reperfusion in a remote organ (hind limb) protects the target organ (heart) against sustained ischemic reperfusion injury. The present study was designed to investigate the possible role of thromboxane A2 in RIPC-induced cardioprotection in rats. Remote hind limb preconditioning was performed by four episodes of 5 min of inflation and 5 min of deflation of pressure cuff. Occlusion of the hind limb with blood pressure cuff is most feasible, non-invasive, clinically relevant, and safe method for inducing RIPC. Isolated rat hearts were perfused on Langendorff apparatus and were subjected to global ischemia for 30 min followed by 120-min reperfusion. The levels of lactate dehydrogenase (LDH) and creatine kinase (CK) were measured in coronary effluent to assess the degree of myocardial injury. The extent of myocardial infarct size along with the functional parameters including left ventricular developed pressure (LVDP), dp/dtmax, and dp/dtmin were also measured. Ozagrel (thromboxane synthase inhibitor) and seratrodast (thromboxane A2 receptor antagonist) were employed as pharmacological modulators of thromboxane A2. Remote hind limb preconditioning significantly attenuated ischemia/reperfusion-induced myocardial injury and produced cardioprotective effects. However, administration of ozagrel and seratrodast completely abolished the cardioprotective effects of RIPC suggesting the key role of thromboxane A2 in RIPC-induced cardioprotection. It may be concluded that brief episodes of preconditioning ischemia and reperfusion activates the thromboxane synthase enzyme that produces thromboxane A2, which may elicit cardioprotection either involving humoral or neurogenic pathway.

Topics: Animals; Benzoquinones; Creatine Kinase; Female; Heart; Heptanoic Acids; Hindlimb; Ischemic Preconditioning; L-Lactate Dehydrogenase; Male; Methacrylates; Myocardial Infarction; Myocardial Reperfusion Injury; Rats, Wistar; Thromboxane A2; Thromboxane-A Synthase

The effect of Y-24180, a potent antagonist to-platelet-activating factor (PAF), was evaluated on the antigen-induced immediate asthmatic response (IAR) in actively sensitized guinea pigs that were pretreated with an antihistaminic agent, pyrilamine. Then, the effect was compared with that of other antiasthmatic agents. In a dose-dependent manner, Y-24180 (0.01-1 mg/kg, p.o.) suppressed the IAR, and WEB 2086 (0.1-10 mg/kg, p.o.), another PAF antagonist, also suppressed IAR in the same fashion as Y-24180. In contrast, AA-2414 (1-100 mg/kg,p.o.), a thromboxane A2 (TXA2) antagonist, was effective only at the beginning of the IAR and ONO-1078 (1-100 mg/kg, p.o.), a peptide leukotriene (pLT) antagonist, was effective only in the latter period, OKY-046, a TXA2 synthetase inhibitor, showed no significant suppression of the IAR at doses up to 100 mg/kg. Thus, PAF antagonists were more effective than the other agents tested in the present model for IAR. In a subsequent test, Y-24180 (1 mg/kg, p.o.) was confirmed to enhance the suppressive effects of theophylline (10 and 30 mg/kg, p.o.), procaterol (0.1 and 1 microgram/kg, i.v.), OKY-046 (100 mg/kg, p.o.) and ONO-1078 (100 mg/kg, p.o.) on the IAR. A combination of three agents, namely Y-24180 with OKY-046 and ONO-1078, completely suppressed the IAR. The results demonstrate that Y-24180 not only suppresses the IAR, but also enhances the suppressive effect of other antiasthmatic agents. Therefore, Y-24180 would be a clinically promising drug for the treatment of bronchial asthma.

Topics: Animals; Anti-Asthmatic Agents; Asthma; Azepines; Benzoquinones; Bronchodilator Agents; Chromones; Drug Interactions; Drug Therapy, Combination; Guinea Pigs; Heptanoic Acids; Male; Methacrylates; Platelet Activating Factor; Theophylline; Triazoles

Effects of Y-24180 on antigen-induced asthmatic responses were evaluated in actively sensitized guinea pigs and the effects were compared with those of several anti-asthmatic drugs.. Male Hartley guinea pigs were used.. Guinea pigs were actively sensitized with ovalbumin and were pretreated with pyrilamine Y-24180 was orally administered to the animals 3 h and others were 1 h before the antigen challenge.. The airway hyperresponsiveness was measured according to the method of Konzett and Rössler with some modifications. The immediate asthmatic response (IAR) and late asthmatic response (LAR) were measured by the oscillation method. Inflammatory cells infiltrated into the lungs were counted after the bronchoalveolar lavage.. Under oral administration before or after the challenge with antigen, Y-24180, OKY-046, and ONO-1078 suppressed the antigen-induced airway hyperresponsiveness. Moreover, Y-24180, ONO-1078, AA-2414, and theophylline suppressed both the IAR and LAR, but OKY-046 only suppressed the LAR. Among the test drugs, only Y-24180 and theophylline suppressed the antigen-induced accumulation of eosinophils in the bronchoalveolar lavage fluid.. The data indicate practical participation of PAF in the development of antigen-induced asthmatic responses in animals, and usefulness of Y-24180 in the clinical treatment of asthma as well as other anti-asthmatic drugs.

Topics: Administration, Oral; Aerosols; Animals; Anti-Allergic Agents; Anti-Asthmatic Agents; Asthma; Azepines; Benzoquinones; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Bronchodilator Agents; Chromones; Enzyme Inhibitors; Guinea Pigs; Heptanoic Acids; Histamine Antagonists; Leukotriene Antagonists; Male; Methacrylates; Ovalbumin; Platelet Membrane Glycoproteins; Pyrilamine; Receptors, Cell Surface; Receptors, G-Protein-Coupled; Serine Proteinase Inhibitors; Signal Transduction; Theophylline; Thromboxane-A Synthase; Triazoles

We established an experimental model of late asthmatic response (LAR) using conscious guinea pigs actively sensitized by antigen aerosol inhalation. In actively sensitized guinea pigs, antigen challenge by aerosol inhalation caused an immediate increase in specific airway resistance (SRaw) (immediate airway response; IAR) followed by a LAR which occurred 4 to 8 hr after antigen challenge. SRaw in the challenged animals was still increased 23 hr after antigen challenge. Examination of bronchoalveolar lavage (BAL) fluid and histology of the lungs revealed increases in eosinophils and neutrophils during LAR. The beta-2 agonist salbutamol inhibited only IAR and not LAR. Dexamethasone inhibited LAR but not IAR. A low dose of theophylline had little effect on both IAR and LAR. A novel thromboxane A2 (TXA2) receptor antagonist, AA-2414, orally administered before antigen challenge dose-dependently inhibited both IAR and LAR, and oral administration of AA-2414 after the IAR inhibited LAR. Also, thromboxane synthetase inhibitors, CV-4151 and OKY-046, reduced both IAR and LAR. Salbutamol significantly reduced the increase in neutrophils in BAL fluid, and dexamethasone significantly reduced the increase in eosinophils and neutrophils in BAL fluid. Theophylline also reduced the increase in eosinophils in BAL fluid. However, AA-2414 did not inhibit the accumulation of these inflammatory cells in BAL fluid or the airway tissues. These results suggest that asthmatic responses in guinea pigs are similar to those in asthmatic subjects and that TXA2 plays an important role in both IAR and LAR but not in inflammatory cell infiltration in this model of allergic asthma.

Topics: Acetylcholine; Airway Resistance; Animals; Antibodies; Asthma; Benzoquinones; Bronchoalveolar Lavage Fluid; Disease Models, Animal; Fatty Acids, Monounsaturated; Guinea Pigs; Heptanoic Acids; Leukocytes; Male; Methacrylates; Ovalbumin; Pyridines; Theophylline; Thromboxane A2