高氧诱导新生鼠肺上皮细胞凋亡损伤与肺表面活性蛋白的变化

摘要

目的：探讨高浓度氧致新生鼠肺损伤时肺表面活性蛋白C、D（SP-C、SP-D）以及肺泡上皮细胞凋亡率的变化。方法生后24 h内的新生大鼠，随机分为空气组和高氧组；空气组常规饲养，高氧组置常压高氧箱内吸入浓度为90%的氧；两组分别于实验第1、3、7、10、14天，取8只新生鼠的肺组织进行苏木精-伊红（HE）染色并观察其病理变化，采用末端标记法检测肺上皮细胞凋亡率。采用酶联免疫法检测支气管肺泡灌洗液（BALF）中SP-C、SP-D。结果空气组新生鼠随日龄增加肺泡逐渐形成，形态规则，大小均匀；高氧组新生鼠随日龄增加肺泡数量逐渐减少，小血管扩张，出血增多，间质细胞增多，肺组织水肿。空气组新生大鼠BALF中的SP-C随日龄增长逐渐降低；高氧组第1天SP-C低于空气组，第3天SP- C高于空气组，第7天达高峰，第10天SP-C的含量开始下降，第14天下降更加明显。空气组SP-D的含量随日龄的增长亦逐渐降低；高氧组第1天SP-D的含量与空气组无明显差异，第3天SP-D的含量开始增加，第7天达到峰值，第10天SP-D的含量开始下降，第14天下降显著。结论长期吸入高浓度氧抑制肺泡发育，随吸入高浓度氧时间的延长，肺上皮细胞凋亡率增加，肺组织中SP-C、SP-D先增高后下降。%ObjectiveTo study the change of the pulmonary surfactant protein C, D (SP-C, SP-D) and apoptosis of alveolar epithelium cells in neonatal rats with hyperoxia-induced lung injury.MethodsThe neonatal rats born within 24 hours were divided into the air group (n=50) and the hyperoxia group (n=50). The lung tissue was collected on the ifrst, third, seventh, tenth, fourteenth day after the hyperoxia exposure. The pathological changes were observed by HE staining. The apoptosis rate of lung epithelial cells was detected by TUNEL (terminal deoxyn ucleotidyl transfer-mediated end labeling). The content of SP-C and SP-D in broncho alveolar lavage lfuid (BALF) was detected by enzyme-linked immunosorbent assay.ResultsIn the air group, as age increased, the alveolar were gradually more completely formed with the regular shape and uniform size. Mean-while, in the hyperoxia group, as age increased, the number of alveolar was reduced, the small blood vessels expanded, the alve-olar hemorrhage was increased, the interstitial cells were increased and the lung tissue was swelling. The levels of SP-C, SP-D decreased with the increase of age in the air group. The level of SP-C in hyperoxia group was lower than that in the air group on the ifrst day. It was higher than that in the air group on the third day, peaked on the seventh day, and then it began to decline on the tenth day and decreased more obviously on the fourteenth day. The level of SP-D in hyperoxia group was not signiifcantly dif-ferent from that in the air group on the ifrst day, was higher than that in the air group on the third day and peaked on the seventh day. Then it began to decline on the tenth day and decreased more on the fourteenth day. ConclusionsLong-term inhalation of high concentrations of oxygen inhibits alveolar development. With the prolonged time of oxygen inhalation, the apoptosis of lung epithelial cells is increased, and the level of SP-C and SP-D in BALF was increased ifrst and then decreased.