豚鼠食管多次盐酸灌注对呼吸道黏膜P物质表达的影响

目的 观察多次盐酸灌注豚鼠食管对呼吸道黏膜内P物质表达的影响.方法 将20只豚鼠按随机数字表法分为模型组和对照组,每组10只.模型组用盐酸氯胺酮将豚鼠轻度麻醉,将5 F胃管插入豚鼠食管至食管中下端,灌注含0.5%胃蛋白酶的0.1 mol/L盐酸(8滴/min,20 min/d),连续灌注14 d.对照组用PBS代替盐酸灌注食管,方法同模型组.在末次灌注后24 h,所有豚鼠应用氯化乙酰胆碱按浓度倍增法(3.125、6.25、12.5、25、50及100μg/kg)依次颈外静脉注射进行支气管激发实验;取左肺组织行HE染色,用抗P物质抗体行免疫组织化学染色.结果 随着乙酰胆碱浓度的成倍递增,模型组与对照组的肺阻力均增加,当浓度达到25μg/kg以上时,模型组与对照组的肺阻力比较差异有统计学意义(t值分别为43.057、51.410和57.359,均P<0.01);免疫组织化学结果显示(染色反应强度用灰度值表示),模型组豚鼠气管和细支气管黏膜内P物质阳性反应的平均灰度值(分别为7±4、85±5)明显低于对照组(分别为16±4、102±6)(t值分别为3.44、2.16,均P<0.01).结论 多次盐酸灌注豚鼠食管后呼吸道黏膜内P物质表达明显增多,提示神经源性炎症可能参与胃食管反流性疾病的发病过程.

The expression of Substance P in airway mucosa of guinea pigs with repetitive esophageal stimulation by hydrochloric acid

Objective To observe the expression of substance P(SP) in the airway mucosa of guinea pigs with repetitive esophageal stimulation by hydrochloric acid (HCL). Methods Twenty adult guinea pigs were randomly divided into 2 groups(n = 10 each) : (1)The HCL model group: On the day of experimentation, guinea pigs were maintained under ketamine anesthesia. A 5F catheter was inserted orally into the lumen of the middle and lower esophagus. The esophagus of each animal was perfused with HCl-P for 20 min/d for 14 d. (2) The PBS control group: The esophagus of each animal was perfused with PBS instead. The bronchial responsiveness to Ach given intravenously with increasing doses (3.125,6.25,12.5, 25,50, 100 μg/kg)was measured after the last perfusion. The left lung was isolated for pathological examination. Lung sections were stained with hematuxylin and eosin, and other sections were prepared for immunohistochemistry using monoclonal antibodies against SP. Results In response to increasing doses of ACh, all guinea pigs showed dose-dependent increases in R<,L>. However, when the dose of ACh was increased to 25 μg/kg, the airway responsiveness increased significantly in the HCl-P model animals compared with the PBS control group (t values = 43.057, 51.410, 57.359 respectively, all P<0.01). The mean gray values of SP decreased significantly in the tracheal epithelia and the distal airway walls of the model group compared with the PBS control group (t values= 3.44, 2.16 respectively, all P<0.01). Conclusion There was airway neurogenic inflammation in guinea pigs with repetitive esophageal stimulation by HCL, which maybe closely related to the pathogenesis of gastro-esophageal reflux disease.