气道速激肽在卵蛋白致敏豚鼠模型咳嗽反应中的作用

目的：研究气道速激肽在卵蛋白致敏和激发豚鼠咳嗽发生机制中的作用。 方法： 正常和卵蛋白致敏豚鼠各20只，卵蛋白雾化吸入激发。24 h后，正常组和致敏组豚鼠随机各分为2组，每组10只，分别依次腹腔注射生理盐水，0.1 mg/kg、0.3 mg/kg和1.0 mg/kg的NK1受体拮抗剂SR140333 或NK2受体拮抗剂SR48968，观察吸入10-4 mol/L的辣椒素溶液诱导的咳嗽反应。用非侵入性方法测量正常和卵蛋白致敏豚鼠注射SR140333或SR48968前后吸入辣椒素溶液所产生的特异性气道阻力。 结果： 致敏豚鼠咳嗽反应明显高于正常对照组［(9.3±1.2)times/3 min vs (19.5±5.7)times/3 min，P<0.05］。SR140333不影响正常对照组豚鼠的咳嗽反应，而SR48968则可降低咳嗽频率达30% (P<0.05)，两者均抑制吸入辣椒素后增加的气道阻力。而在卵蛋白致敏豚鼠，SR140333或SR48968均抑制吸入辣椒素溶液诱导的咳嗽频率［(9.9±4.7)times/3 min，(8.0±1.6)times/3 min，P<0.05］和增高的气道阻力。 结论： NK受体拮抗剂抑制致敏豚鼠卵蛋白激发后增高的咳嗽反应。因此，气道速激肽可能是嗜酸性粒细胞性气道炎症所致咳嗽的重要介质。

Effect of tachykinin on cough response in an ovalbumin-sensitized guinea pig model

AIM: To investigate the role of tachykinin in airway in cough response in guinea pigs sensitized and challenged with ovalbumin. METHODS: 20 normal and 20 sensitized guinea pigs were challenged with the aerosol of ovalbumin. twenty-four hours later, cough response to inhaled capsaicin was measured after the normal and sensitized guinea pigs (10 of each) introperitoneally injected either with 0.1 mg/kg, 0.3 mg/kg and 1.0 mg/kg of NK1 antagonist SR140333 or NK2 antagonist SR48968, respectively. Specific airway resistance was recorded with noninvasive technique. RESULTS: Cough response increased in sensitized guinea pigs compared with control ［(19.5±5.7） times/3 min vs （9.3±1.2） times/3 min, P<0.05］. SR48968FR decreased the cough response by 30% in control guinea pigs (P<0.05), but SR140333 did not. Both prevented an increase in airway resistance after the inhalation of capsaicin. However, SR48968FR and SR140333 inhibited increased cough response ［(9.9±4.7） times/3 min, （8.0±1.6） times/3 min, P<0.05］ and airway resistance induced by the inhalation of capsaicin. CONCLUSION: Neurokinin (NK) antagonist inhibits increased cough response in guinea pigs sensitized and challenged with ovalbumin. Tachykinin may be an important mediator in cough associated with eosinophilic airway inflammation.