外燥对小鼠气道“纤毛-黏液毯”御邪屏障影响的实验研究

Influence of external dryness on defend barrier-cilium-mucous blanket in mouse airway

目的动态观察外燥对小鼠气道局部御邪屏障的影响,研究外燥致病精细病理机制。方法120只无特定病原体级(SPF)昆明种小鼠随机分为常温常湿组、常温燥组、温燥组、凉燥组,每组30只,分批置智能型人工气候箱、模拟外燥"温度-相对湿度-风"综合刺激进行造模。处理后第6、12、18天常规检测各组气管组织病理、气道液总蛋白(P)、气道液黏多糖(MS)和分泌型IgA(SIgA)含量。结果常温燥组气道组织病变不明显;温燥组、凉燥组第6天至第18天气道上皮鳞状化生与纤毛缺损,20%～40%气管浆液腺上皮黏液腺化生,伴炎性细胞浸润,均以第12天为重。与燥相关3个组第12天至第18天P均减少,同期常温燥组MS呈升高趋势,温燥组MS与SIgA则持续下降(P<0.05),凉燥组第12天至第18天P持续下降(P<0.01),伴第12天MS减少(P<0.05)。结论温燥伤肺劫津,气不布津则气道组织失于濡润,伴SIgA持续减少进而加重病变,故减弱气道"纤毛-黏液毯"与局部免疫御邪屏障之功是外燥基本病机之一。第12天明显的气道病变将为研究外燥病机的"最佳观察期"提供依据。

Objective To observe dynamically the influence of external dryness on the local defend barrier in mouse airway, and study the pathogenic mechanism. Method Special pathogenic free （SPF） Kunming mice （n = 120） were randomly divided into the normal-temperature and normal-dampness group （ group A）, normal-temperature and dryness group （ group B）, warm-dryness group （ group C ） and cooldryness group （ group D, each n = 30）. The mouse model was established by the synthetic stimulation of imitated external dryness of temperature-relevant humidity-wind in the intelligent artificial climate box. After 6, 12 and 18 days, the histopathological changes of respiratory tract, and the content of total protein（P）, mucopolysaccharide （MS） and secretory IgA （SIgA） in the fluid of respiratory tract were detected respectively. Result The histopathological changes in airway was not obvious in group B. In group C and D there were squamous metaplasia of airway epithelium and cilium function defect, and epithelial mucous metaplasia of 20% to 40% trachea serous gland accompanied by the infiltration of inflammatory cells from the 6^th day to the 18^th day, which were the most serious on the 12^th day. The content of P decreased from the 12^th day to the 18^th day in group B, C and D, content of MS tended to increase in group B, and content of MS and SIgA decreased continuously in group C （P 〈 0.05）. The content of P decreased continuously in group D from the 12^th day to the 18^th day （P 〈 0.05 ） and the content of MS decreased on the 12^th day （P 〈 0.05）. Conclusion The result reconfirms TCM doctrine of warm-dryness inducing the impairment of lung, and the decrease of SIgA content aggravates the pathological changes. One of the basic pathogeneses of external dryness is related to the attenuation of cilium-mucous blanket and local defend barrier. The result also indicates that the obvious airway pathological changes on the 12^th day provides a base of the best obsenvation phase for the research on the pathogenesis of external dryness.