ono-1301 and beraprost

Epoprostenol (prostacyclin) has been shown to improve survival in pulmonary arterial hypertension. However, this therapy needs continuous intravenous administration devises because of its short half-life. Recently, an orally active prostacyclin analogue, beraprost sodium, and its drug delivery system have been developed in Japan. Beraprost sodium improves pulmonary hemodynamics in patients with pulmonary arterial hypertension. In addition, we have developed ONO-1301, a novel long-acting prostacyclin agonist with thromboxane synthase inhibitory activity. Subcutaneous administration of ONO-1301 markedly attenuated monocrotaline-induced pulmonary hypertension and improved survival in rats. These prostacycline derivates may be promising for the treatment of pulmonary arterial hypertension.

Topics: Epoprostenol; Humans; Hypertension, Pulmonary; Pyridines

ONO-1301 [(E)-[5-[2-[1-phenyl-1-(3-pyridyl)methylidene-aminooxy]ethyl]-7,8-dihydronaphthalene-1-yloxy]acetic acid] is a novel prostaglandin (PG) I2 mimetic with inhibitory activity on the thromboxane (TX) A2 synthase. Interestingly, ONO-1301 retains its inhibitory effect on platelet aggregation after repeated administration, while beraprost, a representative agonist for the PGI2 receptor (IP), loses its inhibitory effect after repeated administration. In the present study, we intended to clarify the mechanism by which ONO-1301 escapes desensitization of an antiplatelet effect. In platelets prepared from wild-type mice, ONO-1301 inhibited collagen-induced aggregation and stimulated cAMP production in an IP-dependent manner. In addition, ONO-1301 inhibited arachidonic acid-induced TXA2 production in platelets lacking IP. Despite the decrease in stimulatory action on cAMP production, the antiplatelet effect of ONO-1301 hardly changed after repeated administration for 10 days in wild-type mice. Noteworthy, beraprost could retain its antiplatelet effect after repeated administration in combination with a low dose of ozagrel, a TXA2 synthase inhibitor. Therefore, we hypothesized that chronic IP stimulation by beraprost induces an increase in TXA2 production, leading to reduction in the antiplatelet effect. As expected, repeated administration of beraprost increased the plasma and urinary levels of a TXA2 metabolite, while ONO-1301 did not increase them significantly. In addition, beraprost could retain the ability to inhibit platelet aggregation after repeated administration in mice lacking the TXA2 receptor (TP). These results indicate that TP-mediated signaling participates in platelet desensitization against IP agonists and that simultaneous inhibition of TXA2 production confers resistance against desensitization on IP agonists.

Topics: Administration, Oral; Animals; Blood Pressure; Cyclic AMP; Epoprostenol; Male; Mice; Platelet Aggregation; Platelet Aggregation Inhibitors; Pyridines; Receptors, Thromboxane A2, Prostaglandin H2; Signal Transduction; Thromboxane A2; Thromboxane-A Synthase

ONO-1301 is a novel drug that acts as a prostacyclin agonist with thromboxane A(2) (TxA(2)) synthase inhibitory activity. We investigated the effect of ONO-1301 on development of airway allergic inflammation.. Mice sensitized and challenged to ovalbumin (OVA) received ONO-1301, OKY-046 (TxA(2) synthase inhibitor), beraprost, a prostacyclin receptor (IP) agonist, ONO-1301 plus CAY10449 (selective IP antagonist) or vehicle during the challenge period. Twenty-four hours after the OVA challenge, airway hyperresponsiveness (AHR) to methacholine was assessed and bronchoalveolar lavage was performed. Lung specimens were excised for goblet cell staining and analysis of lung dendritic cells (DCs). Bone marrow-derived dendritic cells (BMDCs) were generated, in the presence or absence of drugs, for analysis of DC function.. Mice that received ONO-1301 showed significantly lower AHR, airway eosinophilia, T-helper type 2 cytokine levels, mucus production and lung DCs numbers than vehicle-treated mice. These effects of ONO-1301 were mostly reversed by CAY10449. BMDCs treated with ONO-1301 alone showed lower DC functions, such as expression of costimulatory factors or stimulation to spleen T cells.. These data suggest that ONO-1301 may suppress AHR and airway allergic inflammation through modulation of DCs, mainly mediated through the IP receptor. This agent may be effective as an anti-inflammatory drug in the treatment of asthma.

Topics: Animals; Bronchial Hyperreactivity; Dendritic Cells; Disease Models, Animal; Epoprostenol; Female; Inflammation; Methacrylates; Mice; Mice, Inbred BALB C; Ovalbumin; Pyridines; Thromboxane-A Synthase; Thromboxanes