肺不张后复张小型猪肺泡表面活性物质A的表达及CT比较

Expression of Pulmonary Surfactant-associated Protein A and CT Imaging in Lung Re-expansion Minipig after Atelectasis

目的探讨肺不张后复张过程中小型猪肺泡表面活性物质A（SPA）的表达及多层螺旋计算机断层扫描（cT）影像学变化。方法采用18只中国实验用小型猪I系为实验动物，在支气管镜下置入封堵器造成肺不张模型，分别在肺不张后3d、1周及2周取出封堵器，运用CT观察各组肺复张情况，在取出封堵器后2周取实验肺组织，采用免疫组织化学检测SPA的表达。结果SPA在肺不张2周组表达下降，与3d组、1周组比较存在统计学差异（P〈0．05）。CT下比较3组单侧肺不张面积无统计学差异（P〉O．05），而在复张过程中，3d组残留肺不张面积最少，与1周组、2周组比较存在统计学差异（P〈0．05）。取出封堵器后，肺不张1周、2周组之间CT弧度值无明显差异（P〉0．05），但均高于3d组（P〈0．05）。结论肺复张后SPA表达随肺不张时间延长而减少；肺不张后肺复张CT影像学改善取决于发生肺不张时间，此时间在一周内为佳。

Objective To investigate the expression of Pulmonary surfactant-associated protein A （SPA） and the CT imaging in lung re-expansion after atelectasis. Methods The minipig model of lung re-expansion after atelectasis was established. Male China Experimental Miniature Pig-I were randomly divided into three-days atelectasis group （3 d）, one-week atelectasis group （1 week） and two-weeks atelectasis group （2 weeks）, respectively （n=6）. Pigs were euthanized after two weeks of lung re-expansion. The expression of SPA of experimental lung tissue was detected by immunohistochemistry. At specified time point, CT value and imaging changes were measured. Results The expression of SPA was lower in 2 weeks group than that in the other two groups （P〈0.01）. The CT value was lower in 3 d group than that in the other two groups （P〈0.01）, and the degree of lung re-expansion was the highest level in 3 d group among three groups. Conclusions The SPA expression of experimental lung tissue was decreased with atelectasis prolonged. The CT imaging indicated that improvement of lung re-expansion was dependent on the time of the atelectasis and the preferable opportunity of atelectasis cure was within one week.