论文部分内容阅读
目的观察呼吸机机械通气对黏蛋白(MUC5AC)表达的影响,并对其机制进行初步探讨。方法日本大耳兔随机分为对照组、机械通气1、3、6、12和24 h组以及2、5和10 cm H2O呼气末正压(PEEP)组。取支气管肺泡灌洗液(BALF),用ELISA和RT-PCR法检测BALF中肿瘤坏死因子(TNF)-α、白介素(IL)-8、MUC5AC蛋白和mRNA的水平,计数BALF中多型核粒细胞,底物检测法测定中性粒细胞弹力酶(NE)活性。结果机械通气能显著增强MUC5AC的分泌(P<0.05)。通气3 h TNF-α表达至峰值,随后逐渐下降(P<0.05)。通气6 h IL-8表达至峰值,随后逐渐下降(P<0.05)。通气12 h后多型核粒细胞数及中性粒细胞弹力酶活性显著升高,24 h后回降(P<0.05)。随着PEEP的增加,TNF-α、IL-8、MUC5AC mRNA的表达和蛋白含量、多型核粒细胞数和NE活性均随之升高(P<0.05)。结论机械通气能促进气道黏膜上皮细胞分泌MUC5AC,其机制可能与机械通气引发炎性反应有关。
Objective To observe the effect of ventilator mechanical ventilation on the expression of mucin (MUC5AC), and to explore its mechanism. Methods Japanese white rabbits were randomly divided into control group, mechanical ventilation for 1, 3, 6, 12 and 24 h groups, and 2,5 and 10 cm H2O positive end expiratory pressure (PEEP) group. The bronchoalveolar lavage fluid (BALF) was taken and the levels of TNF-α, IL-8 and MUC5AC protein and mRNA in BALF were measured by ELISA and RT-PCR. Cell and substrate assays were used to determine neutrophil elastase (NE) activity. Results Mechanical ventilation significantly enhanced the secretion of MUC5AC (P <0.05). TNF-α peaked at 3 h after ventilation, then decreased gradually (P <0.05). IL-8 expression peaked at 6 h after ventilation, then decreased gradually (P <0.05). After 12 h of ventilation, the number of polymorphonuclear neutrophils and the activity of neutrophil elastase increased significantly, and then decreased 24 h later (P <0.05). With the increase of PEEP, the expression of TNF-α, IL-8 and MUC5AC mRNA, protein content, polymorphonuclear neutrophil count and NE activity were increased (P <0.05). Conclusion Mechanical ventilation can promote the secretion of MUC5AC in airway epithelial cells, which may be related to the inflammatory reaction induced by mechanical ventilation.