[The relationship between H2 receptor of airways and the pathogenesis of bronchial asthma].

In order to explore the relationship between H2 R and the pathogenesis of asthma, we treated 19 stable asthmatic patients with H2-receptor agonist impromidine and observed its effect on bronchial hyperresponsiveness (BHR). The results showed that single dose inhalation of impromidine (2.5mg, in 13 cases) had no effect on the starting respiratory resistance (Rrs) and the minimum amount of cumulative dose (Dmin) to asthmatic airways, while repetitive inhalation of impromidine for 10 days (2. 5mg a day, in 6 cases) decreased the Rrs (P = 0.059) and increased the Dmin significantly (P < 0.05); and that H2R agonist impromidine could reduce the sensitivity of airway to methacholine and improve the BHR of asthmatic patients. The results suggest that H2R agonist may be used as anti-inflammatory drug to treat asthma and H2R may have protective role in the inflammatory reaction of asthmatic airways.