氯胺酮对兔肺缺血/再灌注损伤后细胞凋亡和Caspase-3mRNA表达的影响

目的 观察氯胺酮对兔肺缺血/再灌注损伤后细胞凋亡和Caspase-3 mRNA表达的影响.方法 90只兔建立单肺缺血再灌注模型后,被随机分成3组（每组30只）：对照组（C组）、缺血/再灌注组（I/R组）和氯胺酮组（KET组）.每组30只兔子又平均分成再灌注后1小时、3小时、5小时组.检测各组超氧物歧化物（SOD）活性、丙二醛（MDA）浓度、肿瘤坏死因子α（TNF-α）含量和凋亡指数（AI）变化.图像分析TUNEL染色和原位杂交对肺细胞凋亡及Caspase-3mRNA表达.结果各相同时间点I/R组比C组SOD活性显著降低（P〈0.01）,而MDA、TNF-α含量和AI明显升高（P〈0.01）;与I/R组比较,相同时间点KET组SOD活性升高,而MDA、TNF-α含量和AI则有不同程度降低（P〈0.01或P〈0.05）.肺再灌注后TUNEL法检测阳性细胞主要分布在肺泡上皮细胞和血管内皮细胞,Caspase-3 mRNA表达主要分布在血管内皮细胞;每个时间点I/R组Caspase-3 mRNA表达相比C组显著增加,同时肺细胞凋亡也显著增加.然而,使用氯胺酮后,两者都有明显减少.结论氯胺酮可通过减少缺血/再灌注后MDA、TNF-α含量,提高SOD活性,降低caspase-3 mRNA表达而抑制肺细胞凋亡,减轻再灌注后兔肺损伤.

Effect of ketamine on pneumocyte apoptosis and expression of caspase-3 mRNA after lung ischemia/reperfusion injury in rabbits

Objective To investigate the effect of ketamine on pneumocyte apoptosis and expression of easpase-3 mRNA after lung ischemia/ reperfusion injury in rabbits. Methods Ninety Rabbits used for unilateral lung ischemia/reperfusion model were randomly divided into three groups （thirty rabbits in each group）： control group （C group）, ischemia/reperfusion group （I/R group） and ketamine group （KET group）. 30 rabbits in each group were averagely divided at lh, 3h, 5h after reperfusion. The activity of superoxide dismutase（SOD）, concentration of malondialdehyde（MDA）, con- tent of tumor necrosis factor-alpha（TNF-ct） and change of apoptosis index（AI） at each groups were measured respectively in different groups. TUNEL staining and in situ hybridization were used to detect pneumocyte apoptosis and expression of Caspase-3 mRNA; Image analysis was also performed. Results The activity of SOD was significantly lower in I/R group than in C group （P〈0.01） at the same time point; while the content of MDA, TNF- ctand AI were obviously higher in I/R group than in C group （P〈0.01）. Compared with I/R group, the level of SOD was higher, however, MDA, TNF-a and AI were lower at different degree （P〈0.01 or P〈0.05） in KET group at the same time point. TUNEL-positive cells were mainly located in alveolar epithelial cell and vascular endothelial cell, the expression of Caspase-3 mRNA were mainly located in vascular endothelial cell after the lung reper- fusion. The expression of caspase-3 mRNA in the I/R groups was significantly increased compared with that of C groups at each time point. Mean- while, pneumocyte apoptosis was also enhanced. Whereas both of them were sharply decreased after ketamine was used. Conclusion Ketamine could inhibit the pneumocyte apoptosis during pulmonary ischemia/reperfusion injury by reducing contents of MDA, TNF-a, increasing the activity of SOD, and decreasing expression of caspase-3mRNA, thus alleviated injury on pulmonary tissue of reperfusion injuried rabbits.