基于咳嗽波形构建化学刺激诱导的咳嗽模型及实验验证

Construction and Experimental Validation of Chemically-induced Cough Model Based on Cough Waveforms

摘要:

目的 利用全身体积描记系统（WBP）构建以咳嗽波形计数咳嗽次数的化学刺激诱导的咳嗽模型，并基于该模型探索白果中分离的新化合物GK-A的止咳作用。方法 分别采用不同的化学试剂刺激小鼠和豚鼠诱导咳嗽，利用WBP监测呼吸波形，寻找可识别、典型的咳嗽波形，计数咳嗽次数；采用不同浓度的枸橼酸或辣椒素诱导豚鼠咳嗽，以咳嗽波形计数咳嗽次数，优化刺激条件，构建咳嗽模型；选用右美沙芬对构建的豚鼠咳嗽模型进行验证；利用构建的辣椒素豚鼠咳嗽模型进一步探究GK-A的止咳作用。结果 WBP能够通过可识别的、典型的呼吸波形计数辣椒素和枸橼酸诱导的豚鼠咳嗽次数；通过对模型优化，确定将辣椒素浓度100 μmol·L^-1，雾化时间2 min作为模型刺激条件构建咳嗽模型；验证结果显示，与模型组比较，WBP计数的右美沙芬组豚鼠咳嗽次数明显减少（P<0.05），咳嗽潜伏期显著延长（P<0.01）；GK-A明显延长氨水诱导的小鼠咳嗽模型的咳嗽潜伏期（P<0.05）并降低咳嗽次数（P<0.05）；GK-A能延长辣椒素诱导的豚鼠咳嗽模型的咳嗽潜伏期（P<0.05），减少咳嗽次数（P<0.05）并降低豚鼠血清中P物质（SP）含量（P<0.05，P<0.01）。结论 成功构建以咳嗽波形计数的辣椒素诱导的豚鼠咳嗽模型，咳嗽计数客观、准确。GK-A具有止咳作用，其作用机制可能与抑制神经肽SP有关。

Abstract:

Objective To construct a cough model induced by chemical stimuli by whole-body plethysmography （WBP） for counting coughs based on cough waveforms， and use this model to explore the antitussive effect of GK-A.Method Different chemical stimuli were used to induce coughs in mice or guinea pigs. Respiratory waveforms were monitored by WBP， and the recognizable and typical cough waveforms were selected for cough counting. Guinea pigs were induced to cough with different concentrations of citric acid or capsaicin， and cough waveforms were used to optimize the stimulation conditions. The optimized guinea pig model of cough was validated with dextromethorphan， and the optimized guinea pig model of capsaicin-induced cough was used to evaluate the antitussive effect of GK-A.Result WBP could count the coughs induced by capsaicin and citric acid in guinea pigs by recognizable and typical respiratory waveforms. The optimized stimulation conditions were capsaicin concentration of 100 μmol·L^-1 and nebulization for 2 min. The validation results showed that compared with the model group， the dextromethorphan group of guinea pigs had reduced coughs （P<0.05） and prolonged cough latency （P<0.01）. GK-A prolonged the cough latency （P<0.05） and reduced coughs （P<0.05） in the mouse model of ammonia-induced cough. In the guinea pig model of capsaicin-induced cough， GK-A prolonged cough latency （P<0.05）， reduced coughs （P<0.05）， and decreased substance P （SP） content in the guinea pig serum （P<0.05， P<0.01）.Conclusion A guinea pig model of capsaicin-induced cough was successfully established based on cough waveform counting， which provided an objective and accurate cough counting method. GK-A has antitussive effects， possibly by inhibiting the neuropeptide SP.