低温保护液肺动脉灌注对合并重度肺高压病儿术后肺组织eNOS和iNOS表达的影响

Effects of pulmonary artery perfusion with hypothermic solution on eNOS and iNOS expression in lung of infants with pulmonary hypertension

目的 利用免疫组织化学技术研究低温肺保护液对体外循环 (CPB)后内皮源型一氧化氮合酶 (eNOS)和诱生型一氧化氮合酶 (iNOS)在肺血管内皮细胞、支气管上皮和肺泡巨噬细胞表达的影响。方法 34例合并重度肺高压的先天性心脏病病儿在常规低温体外循环下行心内畸形矫治术。分为对照组(2 3例 )和保护组 (11例 ) ,保护组在主动脉阻断后肺动脉内灌注低温肺保护液。两组体外循环后取右下肺组织利用免疫组织化学技术观察肺血管内皮eNOS、支气管上皮iNOS和肺泡巨噬细胞iNOS的表达情况。结果 术后肺血管内皮细胞eNOS表达 ,保护组为 2 2 4± 0 6 0 ,对照组为 0 92± 0 70 (P <0 0 1) ;支气管上皮iNOS表达 ,保护组为 0 88± 0 6 0 ,对照组 2 0 8± 0 6 4 (P <0 0 1) ;肺泡巨噬细胞iNOS表达 ,保护组 10 6± 40 ,对照组 2 80± 75 0 (P <0 0 1)。结论 低温保护液肺动脉灌注可以保持eNOS在肺血管内皮细胞的表达 ,防止肺泡巨噬细胞和气管上皮细胞iNOS的过度表达 ,减轻肺内炎症反应 ,从而减轻CPB后肺高压病儿的肺损伤。

Objective: The expression of eNOS and iNOS in lung tissues plays an important role in lung injury after cardiopulmonary bypass. The aim of this study is to evaluate the effect of pulmonary artery perfusion with hypothermic solution on eNOS and iNOS expression in lung tissue during CPB. Methods: 34 young children with congenital heart disease and pulmonary hypertension were divided into the control group (n=23) and protective group (n=11). The basic parameters (age, weight, data of catheterization and other assistant examination) were similar. In the control group, operation were performed using routine techniques, and in the protective group, pulmonary artery was infused with 4℃ protective solution during CPB. Immunohistochemical analysis was performed on 4-μm paraffin sections of lung tissue at end of CPB. The distribution and expression of eNOS and iNOS in pulmonary endothelium, bronchi epithelium and macrophages were studied using the immunohistochemical technique. Results: The strong iNOS-expression was showed in pulmonary endothelium (2.24±0.60) and lower iNOS-expression in bronchia epithelium (0.88±0.60) and alveolar macrophages (10.6±4.0) in protective group and lower eNOS-expression in endothelia and over iNOS-expression in alveolar macrophages and bronchia epithelia in the control group (P<0.01).Conclusion: Pulmonary artery perfusion with hypothermic solution could keep normal iNOS-expression in pulmonary vessel endothelium, retard over-expression of iNOS in alveolar macrophages and bronchia epithelium, inhibit inflammatory response in lung and ameliorate hemodynamics and airway resistance.