摘要目的 观察感觉神经肽P物质及其受体拮抗剂对气道平滑肌细胞(airway smooth muscle cell,ASMC)钠钙离子交换体(sodium-calcium exchange,NCX)离子电流的影响.方法 原代培养气道平滑肌细胞;荧光免疫细胞组化识别ASMC;膜片钳技术检测乙酰胆碱(acetylcholine,Ach)、感觉神经肽P物质、感觉神经肽P物质受体拮抗剂GR203040(神经激肽1受体,neurokinin-1 receptor,NK-1R)、钙离子拮抗剂(尼莫地平)干预前后ASMC细胞NCX离子电流变化.根据电压、电流变化绘制电压-电流曲线.PA代表电流幅度,PF代表细胞面积,PA/PF代表电流密度.结果 随着电压增加电流增加,在电压增加至-40 mV时出现反向电流.当电压增加至60 mV时,乙酰胆碱干预组电流密度最大,尼莫地平干预组电流密度最小.P物质干预组电流密度较正常组增加,但弱于乙酰胆碱干预组(P＜0.05);P物质拮抗剂干预组电流密度较尼莫地平干预组强,但较其他组均弱(P＜0.05).结论 在哮喘气道因钙离子负载会引起反向模式电流出现.感觉神经肽P物质会增强NCX离子电流,NK-1R拮抗剂会减轻NCX离子电流,可能会有助于减轻哮喘气道炎症及气道高反应性.

abstractsObjective Investigate the effect of substance P and receptor antagonist on the current of NCX in ASMC.Methods Primary rat ASMC cultures were established.Immunofluorescence was used to identify ASMCs.Patch clamp exam was used to assess NCX currents in ASMC before and after intervented by Ach,substance P,NK-1R receptor antagonist and nimodiping,Voltage-current curves were drawn according to variation of voltage and current.PA indicates current amplitude,PF indicates cell area,and PA/PF indicates current density.Results As the voltage increased,the current density increased.When voltage up to-40mV the reverse current appeard.When the voltage is 60mV the current density in the Ach intervention group was highest,but lowest in the nimodipine intervention group;the current density in the substance P intervention group is more than in control group but lower than in Ach interevention group.The current density in the substance P receptor antagonist intervention group higher than nimodipine interevention goup,but lower than the other group (P ＜0.05).Conclusion In asthma airways,Ca2 + overload is related to the appearance of reverse-mode NCX.NK-1R antagonist plays a role in decreasing the Ca2 + concentration,which can relieve the current of reverse-mode NCX,and may benefit alleviating airway inflammation and responsiveness.As a result,NK-1R antagonist may be an attractive target for therapeutic approaches to asthma.