[Molecular pharmacology and application to the bronchial asthma of thromboxane A2 antagonists]

Lung tissues are capable of forming a large amount of thromboxane (TX) A2. In addition to platelet aggregation and artery smooth muscle contraction, TXA2 induces potent contraction of the airway smooth muscles and airway hypersensitivity, suggesting that this arachidonate cyclooxygenase metabolite can contribute to a pathophysiological role for bronchial asthma as well as cardiovascular diseases. In this respect, many compounds competitively antagonizing TP (PGH2/TXA2) receptor, which is stimulated by not only TXA2 but also prostaglandin (PG) D2, PGF2 alpha, PGH2 and others, have been developed so far. Among these, several compounds have been proved or are being proved to be beneficial for treating of bronchial asthma in clinical. In this review, the efficacy of TP receptor blockers for bronchial asthma through the experimental results reported was discussed.