Involvement of thromboxane A2 in bronchial hyperresponsiveness of asthma

✍ Scribed by Masaki Fujimura; Yasuto Nakatsumi; Kouichi Nishi; Kazuo Kasahara; Tamotsu Matsuda

• Publisher: Elsevier
• Year: 1995
• Tongue: English
• Weight: 614 KB
• Volume: 8
• Category: Article
• ISSN: 0952-0600
• DOI: 10.1006/pulp.1995.1034

✦ Synopsis

It has been considered that thromboxane As (TXA2) is involved in the development of bronchial hyperresponsiveness (BHR), a characteristic feature of asthma. To ensure the involvement of TXA2 in BHR of asthma, effects of a 1-week treatment with two orally active TXA~ antagonists, BAY u 3405 and S-1452, on BHR were examined in 10 and 13 patients with stable asthma, respectively, in two consecutive double-blinded, randomized, placebo-controlled, two-phase crossover studies. Provocative concentration of methacholine causing a 20% fall in FEV~ (PC2o-FEVI) with BAY u 3405 (0.78 (GSEM, 1.50) mg/ml) was significantly greater than the value with placebo (0.65 (GSEM, 1.46) mg/ml) (ratio 1.23 times, 95% CI 1.01 to 1.46: P=0.0401). PCz0-FEVI was also significantly increased with S-1452 (0.43 (GSEM, 1.39) mg/ml) compared with placebo (0.29 (GSEM, 1.27) rag/ ml) (ratio 1.75 times, 95% CI 1.05 to 2.45: P=0.0189). Baseline pulmonary function was not altered by these treatments. These results may ensure that TXA2 is significantly involved in the BHR of asthma while the degree of contribution may be small.