[Thromboxane A2 synthase inhibitor and receptor antagonist].Nihon Rinsho 2001; 59(10):1986-91NR
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.