呼吸道合胞病毒感染对豚鼠咳嗽相关气道功能及其神经递质的影响

Effects of respiratory syncytial virus infection on cough-related airway function and neurotransmitter in guinea pigs

目的观察呼吸道合胞病毒RSV（感染）对豚鼠咳嗽相关的气道功能及神经递质的影响，探讨病毒感染后咳嗽的发病机制。方法雄性SPF级豚鼠60只，按数字随机法随机分成正常对照组、病毒感染组和哮喘组，病毒感染组按病毒感染后天数分为6、12、28和42d四个组，每组10只。通过滴鼻方法接种RSV。Buxco肺功能仪测定咳嗽反射敏感性（CRS）及气道反应性（AR）。荧光定量PCR（Realtime PCR）方法检测辣椒素受体亚型1（VR1）的mRNA表达，免疫组织化学方法检测肺组织VRl及蛋白基吲产物9．5（PGP-9．5）的蛋白表达。结果病毒感染6、12、28、42d组豚鼠CRSE（8．00±3．86）、（8．70±6．20）、（7．60±4．40）和（6．70±3．71）CCnt]均较正常对照组[（2．50±1．43）CCnt]升高（P值均〈0．05），并在12d组达到最高峰（P〈0．01）。感染后12d组豚鼠AR对2个高浓度乙酰甲胆碱刺激结果为（1069±156）％和（1846±285）％，均高于正常对照组（P值分别〈0．05和0．01）。感染后6、12和28d组VRl的mRNA水平分别为1．57±0．43、1．61±0．47和1．68±0．56，均较正常对照组（1．00±0．34）升高（P值均〈0．05），而以28d组为最高。与正常对照组相比，感染后28d组VRl蛋白表达增强（PG0．05）：而感染后12d组PGP9．5表达增强（P〈0．05）。结论CRS增高伴随一定程度的AR增高是RSV引起咳嗽的特点，感染引起VR1和PGP9．5的时空变化可能与病毒感染性咳嗽的发病机制有关。

Objective To investigate the effects of respiratory syncytial virus （RSV） infection on cough-related airway function and neurotransmitter in guinea pigs and to explore the pathogenesis of cough after RSV infection. Methods Sixty SPF male guinea pigs were randomly divided into control group,asthma group and four RSV infected groups （6,12,28 and 42 d group） , ten in each group. Infected animals were inoculated by intranasal instillation of RSV suspension. Plethysmography was used to assess cough reflex sensitivity （CRS） and airway responsiveness （AR）. Vanilloid recepto-1 （VR1） mRNA level was detected by real-time PCR. The protein expressions of VR1 and protein gene product-9.5 （PGP 9.5） were measured by immunohistochemistry. Results CRS in 6, 12, 28 and 42 d RSV-infected group [（8.00±3.86）,（8.70±6.20）,（7.60±4.40）and（6.70±3.71）CCnt] was higher than that in control group [ （2.50± 1.43） CCnt, all P 〈0.05] and reached a peak in 12 d RSV-infected group （ P 〈0.0 ] ）. AR to two high concentrations of methylocholine in 12 d RSVinfected group [（1 069 ± 156 ）%, （1 846±285）G] was higher than that in control group （all P 〈0. 05）. VR1 mRNA level in 6,12,28 and 42 d RSVinfected group （1.57±0.43,1.61±0.47 and 1.68±0.56） was higher than that in control group （1.00±0.34, P〈0.05）, and remained at highest level in 28 d RSV-infected group. Compared with control group, VR1 protein expression in 28 d RSV infected group and PGP 9.5 in 12 d RS±infected group increased （all P 〈0.05）. Conclusions The increased CRS with increased AR in a certain degree is the feature of cough caused by RSV. The temporal and spatial variation of VR1 and PGP-9. 5 may be related to the pathogenesis of cough caused by RSV.