克仑特罗对COPD大鼠膈肌细胞凋亡影响的实验研究

目的探讨克仑特罗对慢性阻塞性肺疾病（COPD）模型大鼠膈肌细胞凋亡及凋亡相关蛋白Fas表达的影响。方法将雄性SPF级Wistar大鼠随机分为A、B、C三组，各组再分为造模前、造模2周、造模4周三个亚组。A组正常喂养；B、C组用气管注入脂多糖（LPS）加烟熏法造模；C组在造模基础上给予克仑特罗干预。用磷酸脱氧尿嘧啶缺口末端标记及免疫组化法检测各组膈肌细胞凋亡率及Fas表达率。结果4周后，经肺HE切片证明B、C组造模成功。随时间推移，A组各亚组间细胞凋亡阳性率及Fas表达率无统计学差异，B、C组造模2周、4周亚组显著高于同期A组（P均〈0．01），B、C组各亚组间无统计学差异；C组造模2周、4周亚组细胞凋亡阳性率显著低于同期B组（P〈0．05）。结论烟雾、LPS在COPD形成过程中参与膈肌细胞凋亡调控，克仑特罗可能通过抑制氧化应激反应和下调Fas表达减少膈肌细胞凋亡，对COPD所致的膈肌疲劳有一定治疗作用。

Experimental research of the effect of Clenbuterol on diaphragmatic muscle cell apoptosis in the models of chronic obstructive pulmonary disease rats

Objective To investigate the effect of Clenbuterol on diaphragmatic muscle cell apoptosis and the expression of Fas, which led to the beginning of the apoptosis, in the models of chronic obstructive pulmonary disease （COPD） rats. Methods Male Wistar rats were randomly divided into three equal groups, control group （group A） , replication of COPD group （ group B）, Clenbuterol group （ group C）. Each group was further divided into three subgroups of pre-replication, replication 2 week, 4 week subgroups. Rats in group B and C by inhaling smoke and injecting LPS into tracheas to replicate the models of COPD, rats in group C were treated by Clenbuterol after inhaling smoke every day. Apoptosis rates and Fas expressions of diaphragmatic muscle cell were examined by the streptavidin biotin-peroxidase complex immunohisto-chemistry techniques and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling （TUNEL）. Results After 4 weeks, COPD model were successfully replicated in the 4 week subgroups of B, C groups proved by lung HE chip. With time-lapse, Apoptosis rate and the expression of Fas were no statistical difference in subgroups of A group ; but were higher in 2 week, 4 week subgroups of group B and C than that in subgroups of A at the same time （ all P 〈 0.01 ）, there were no difference in the subgroup of group A and B ; the cell apoptosis rates of 2 week, 4 week subgroups in group B and C were lower than that in group A（P 〈 0.05 ）. Conclusions Smoking and LPS take an important part in the process of diaphragmatic muscle cell apoptosis in the models of COPD. Clenbuterol can decreased diaphragmatic muscle cell apoptosis by inhibiting the reaction of oxidative-stress and downregulating the expression of Fas, which contributes to the therapeutic effect on diaphragmatic fatigue of the models of COPD rats.