中文摘要：

目的探讨5溴脱氧尿苷（bromodeoxyuridine，Brdu）和端粒酶逆转录酶（tolomerase reverse transcriptase，TERT）标记肺干细胞特点及其在肺发育和损伤修复中的作用。方法95％左右氧气7d制备新生鼠高氧肺损伤模型；将Brdu自腹腔注入模型鼠，免疫组化法检测Brdu和TERT阳性显色细胞，并和表面蛋白C（surfactant protein C，SPC）抗体免疫双染。结果（1）Brdu阳性显色部位主要在各级支气管黏膜下和肺间隔，支气管黏膜上皮及肺泡壁有散在分布，阳性细胞数量较少，多呈立方形、核大；TERT阳性显色在外周肺组织，肺间隔和肺泡肇部位，数量明硅少于Brdu，且阳性显色呈不对称性，即多集中在某一肺叶；（2）SPC阳性显色细胞在肺间隔和肺泡壁，分别和Brdu、TERT双染，可见少量阳性细胞；（3）Brdu、TERT和SPC表达积分在高氧组与正常氧组差异无统计学意义（P〉0．05）。Brdu表达积分无论在高氧组（1．61±0．83）还是正常氧组（1．43±0．85），均高于TERT（分别为0．83±0．84和0．62±0．55，P〈0．05）。结论Brdu和TERT作为肺干细胞标记，两者各有其特征；肺损伤时Brdu和TERT标记阳性细胞量可提示肺干细胞增殖分化及肺泡Ⅱ型上皮细胞损伤修复情况。至于Brdu和TERT哪一个指标更具特异性，是否Brdu同时标记了已从干细胞增殖分化但尚保留干细胞特征的短暂扩增细胞，或TERT更能反映干细胞特征尚待深入研究。

英文摘要：

Objective To investigate the characteristics of stem cells marked with bromodeoxyuridine （Brdu） and telomerase reverse transcriptase （TERT） in lung tissue, as well as its effects on pulmonary development and injury-repair. Methods A model of hyperoxia in neonatal rats was established by exposed to 95% O2 for 7 days. Before executing rats, Brdu was injected peritoneally, then Brdu and TERT positive cells were detected by immunohistochemistry. Results （1）The positive staining cells of Brdu with large nuclear located in septa and submucose of series bronehia, scattering in epithelium of bronehia, and the number of positive cells were less. The positive staining cells of TERT located in the septa and alveolar walls of peripulmonary tissue and the number of which was less than that of Brdu. （2）The positive cells of SPC located in septa and alveolar walls. Staining with Brdu and TERT, small number of positive cells was observed. （3） In hyperoxia and normal oxygen group, integral of expression of Brdu, TRET and SPC had no differences, But integral of expression of Brdu in whatever hyperoxia （1. 61 ± 0. 83） or normal oxygen group （1.43 ± 0. 85） were higher than TRET and SPC （P〈0.05）. Conclusions Brdu and TERT may be as markers of stem cell in lung tissue with different characters, indicating the proliferation and differentiation of pulmonary stem cells and repair of AEC Ⅱ in lung injuries. It remains to be investigated for the speciality of Brdu and TERT in marking stem cells in the future.