目的  探讨经单次大剂量放疗前后肺癌A549 细胞膜磷脂含量的变化，研究细胞膜磷脂代谢及信号传导途径与 肺癌A549 细胞放疗反应之间的关系。方法  应用HPLC 检测分析经单次5Gy 照射后24 小时肺癌A549 和照射前细胞膜磷 脂的含量，对比分析不同磷脂组分含量变化，并研究其含量变化与放疗疗效的关系。结果  HPLC 分析结果显示PI、PE、 PC 3 种膜磷脂含量在照射后降低，分别为PI：1.53±0.07、1.09±0.20，PE：51.69±4.32、32.47±6.60，PC：128.79±7.40、 82.70±3.02，有统计学显著差异（P ＜ 0.01），PS 虽改变但无显著性意义。结论  肺癌A549 细胞经单次大剂量照射后细胞 膜磷脂含量发生了改变，并推测与肿瘤细胞，凋亡、坏死等信号传导有关，对其脂类变化的深入研究以及对探讨肺癌立体 定向放射治疗具有重要意义。

Objective To investigate the changes of A549 cell membrane phospholipids in lung cancer A549 cells before and after radiotherapy, and the relationship between cell membrane phospholipid metabolism and signal transduction pathway and the response of lung cancer cells to radiotherapy. Methods HPLC was used to detect the content of phospholipids in the lung cancer cells before and after 5Gy irradiation in 24 hours after A549 irradiation, to compare and analyse the content of phospholipids, in order to study the relationship between the change of the content and the effect of radiotherapy. Results The analytic result of HPLC showed the content of membrane phospholipid PI, PE and PC decreased in the A549 cell membrane after radiotherapy, with statistics significant deviation (P<0.01), PI: 1.53±0.07, 1.09±0.20, PE: 51.69±4.32, 32.47±6.60, PC: 128.79±7.40, 82.70±3.02, the content of membrane phospholipid PS is more in after radiotherapy than in before radiotherapy, but did not have statistics significant deviation. Conclusions The content of lipids decreased in lung cancer cell in radiotherapy. It is speculated that it is related to tumor cells, apoptosis and necrosis. Therefore, the study on the changes of lipids is of great significance in the treatment of lung cancer with stereotactic radiotherapy (SBRT).