本研究旨在观察肝素吸入对乙酰甲胆碱激发的支气管高反应性的影响。以13例稳定期轻度哮喘患者为研究对象,男6例,女7例,年龄17～56岁,平均30±11岁,病程6个月至23年,平均7±7年,均无吸烟史。全部患者在试验前3个月之内均无哮喘急性发作或呼吸道感染,部分患者在稳定期间服用一些抗炎药物,并在试验期间仍继续服用。但试验前24小时停用β_2受体激动剂。以单盲,交叉,随机的方法让患者吸入肝素或安慰剂,45分钟后再进行乙酰甲胆碱激发试验,两次试验期至少间隔7天。肝素吸入浓度为5000U/ml,肝素用量为1000U/kg,最大量用至60000U。乙酰甲胆碱激发试验的起始浓度为0.125mg/ This study aimed to investigate the effects of heparin inhalation on methacholine-induced bronchial hyperresponsiveness. Thirteen patients with stable mild asthma were studied. There were 6 males and 7 females, aged from 17 to 56 years (average 30 ± 11 years) with a duration of 6 months to 23 years (mean, 7 ± 7 years), with no smoking history. All patients had no acute episodes of asthma or respiratory tract infection within the first 3 months of the trial. Some patients took some anti-inflammatory drugs during the stabilization period and continued taking them during the trial. However, beta 2 agonists were discontinued 24 hours prior to the experiment. Patients were challenged with either heparin or placebo in a single blinded, crossover, randomized trial, followed by a methacholine challenge 45 minutes later, with at least 7 days between trials. Heparin inhalation concentration of 5000U / ml, the amount of heparin 1000U / kg, the maximum amount to 60000U. The initial concentration of methacholine challenge test was 0.125 mg /