利用脱氧核糖核酸末端转移酶介导的ｄＵＴＰ缺口末端标记（ＴＵＮＥＬ）技术、增殖细胞核抗原（ＰＣＮＡ）免疫组织化学染色对不同阶段吸烟小鼠呼吸道粘膜上皮凋亡细胞、增殖细胞的阳性细胞率与分布进行检测，并结合电镜的形态学观察对照研究。结果：正常呼吸道粘膜上皮凋亡细胞位于表层、增殖细胞带位于基底部，而吸烟小鼠丧失了上述分布特征。小鼠吸烟４周时，呼吸道上皮凋亡细胞和增殖细胞阳性率均明显高于未吸烟正常对照组。吸烟８周时，凋亡细胞和增殖细胞阳性率与吸烟４周时相比明显减少。吸烟１２周时，凋亡细胞明显增多，而增殖细胞明显减少。结论：吸烟小鼠呼吸道上皮开始不仅存在大量细胞凋亡而且出现活跃的细胞增殖，随着吸烟时间延长，呼吸道上皮以细胞凋亡占优势，呈现为细胞损伤逐渐加重而细胞再生修复能力减弱的病变特征 The positive rate and distribution of apoptotic cells and proliferating cells in respiratory mucosal epithelium of smoking mice at different stages were detected by DNA nick end-transferase-mediated dUTP nick end labeling (TUNEL) and proliferating cell nuclear antigen (PCNA) immunohistochemical staining The test was carried out, and electron microscopy morphological observation control study. Results: The apoptotic cells in the normal respiratory mucosa epithelium were located in the surface layer, while the proliferating cells were located in the basal part. However, the smoking mice lost the distribution characteristics. At 4 weeks after smoking, the positive rates of apoptotic cells and proliferating cells in respiratory epithelium were significantly higher than those in non-smoking normal control group. At 8 weeks of smoking, the positive rate of apoptotic cells and proliferating cells was significantly decreased compared with the 4th week of smoking. At 12 weeks of smoking, the number of apoptotic cells increased significantly while the number of proliferating cells decreased significantly. CONCLUSIONS: In respiratory tract epithelium of smoking mice, not only a large number of apoptotic cells but also active cell proliferation begin to occur. With the prolongation of smoking time, the apoptosis of respiratory epithelium takes the predominance of apoptosis, presenting as a lesion with gradual cell injury and weakened cell regeneration and repair ability feature