体外循环肺肿瘤坏死因子表达与细胞凋亡的研究

目的：探讨肺组织肿瘤坏死因子-α（tumor necrosis factor-α,TNF-α）在体外循环（cardiopulmonary bypass,CPB）中的表达及其与细胞凋亡的关系。方法：选取健康新西兰大白兔20只,随机分为CPB组和Sham组（单纯开胸）。测定各组围CPB期左心房、右心房血液中中性粒细胞计数、TNF-α含量;取肺组织样本,动态观察肺组织TNF-αmRNA表达、细胞凋亡相关因子Bcl-2、Bax、Fasl的表达和Bcl-2/Bax及凋亡指数变化情况。结果：CPB后,中性粒细胞在肺内明显聚集,肺源性TNF-α的表达及释放显著增加。同时,肺组织细胞凋亡指数明显提高,肺泡上皮细胞Fasl、Bax蛋白表达增加,Bcl-2蛋白表达下降。结论：CPB可引起肺源性TNF-α表达增高并诱发细胞凋亡,从而导致肺损伤。

The study of the relationship between tumor necrosis factor-a and apoptosis on lung tissue after cardiopulmonary bypass

Objective：To study the relationship between tumor necrosis factor-a（TNF-a） and apoptosis on lung tissue after cardiopulmonary bypass（CPB）. Methods： Twenty New Zealand rabbits were selected and randomly divided into two groups： group CPB underwent CPB; group Sham only received open chest operation. Blood neutmphils count, TNF-ct from right and left atrium in the two groups were determined perioperatively. Lung TNF-ctmessenger RNA, Bcl-2 protein, Bax protein, Fasl protein, Bcl-2/Bax, apoptosis index were meas- ured in the lung tissues. Results： CPB can increase leukocyte accumulation, the expression of TNF-ct. Moreo- ver, CPB can also increase the expression of Fasl and Bax on alveolar epithelial cells and decrease of the ex- pression of Bcl-2. Conclusion： CPB can increase the expression of TNF-a and induce lung tissue apoptosis, which cause lung injury.