七氟烷对幼鼠不同脑区多聚腺苷二磷酸核糖聚合酶-1表达和远期认知功能的影响

The effects of sevoflurane on expression of protein Poly （ADP-ribose）polymerase-1 and cognitive function in neonatal rats

目的 观察七氟烷对幼鼠不同脑区神经元细胞多聚腺苷二磷酸核糖聚合酶-1[Poly（ADP-ribose）polymerase-1,PARP-1]表达、远期学习记忆能力及空间探索能力的影响. 方法 出生后7d的wistar幼鼠105只采用随机数字表法随机分为模拟麻醉组（A组）、1％七氟烷麻醉2h组（B组）、1％七氟烷麻醉4h组（C组）、2％七氟烷麻醉2h组（D组）和2％七氟烷麻醉4h组（E组）.麻醉结束后即刻,每组随机选3只,左心室取血进行血气分析.麻醉结束6h后,每组随机选6只幼鼠,分别取大脑皮层和海马组织,用Western blot方法检测PARP-1蛋白表达量.其余实验动物,分别在幼鼠成长至5周、8周、14周时,进行悬崖逃避实验和旷场实验. 结果 各组实验动物无缺氧和明显的CO2蓄积.与A组比较,E组海马PARP-1蛋白表达量明显增加,其他实验组无明显升高：A组（0.32±0.53）,B组（0.45±0.11）、C组（0.46±0.15）、D组（0.34±0.14）、E组（0.80±0.34）（P＜0.05）,各组皮层PARP-1蛋白表达量差异无统计学意义（P＞0.05）.A组（0.34±0.07）、B组（0.33±0.14）、C组（0.28±0.11）、D组（0.29±0.13）、E组（0.38±0.15） （P＞0.05）.5周时接受七氟烷麻醉的大鼠在旷场中平面活动及垂直活动均多于模拟麻醉幼鼠（平面活动时间/s）：A组（431±32）、B组（463±27）、C组（448±31）、D组（467±23）、E组（473±25）（P＞0.05）；垂直面进入时间/s：A组（112±37）、B组（169±46）、C组（152.3±44.3）、D组（150±26）、E组（129±36）（P＞0.05）；8周和14周时,各组动物旷场表现差异无统计学意义（P＞0.05）.5周、8周及14周时,各组动物悬崖逃避实验表现差异无统计学意义（P＞o.05）. 结论 2％七氟烷作用于发育期的幼鼠4h,可导致PARP-1表达增加,诱发海马神经元凋亡；使成长中幼鼠在陌生环境中活动增加,影响其空间探索认知能力.

Objective To investigate the effect of sevoflurane anesthesia on the expression of poly（ADP-ribose） polymerase1 （PARP-1） protein in various brain region of neonatal mice and it＇s learning ability as an adult.Methods 105 neonatal wistar rats （7 days postnatal,P7） were randomly divided into sham anesthesia group （group A）,1% sevoflurane anesthesia for 2 h group （group B）,1% sevoflurane anesthesia for 4 h group （group C）,2% sevoflurane anesthesia for 2 h group （group D） and 2%sevoflurane anesthesia for 4 h group （group E）.Arterial blood samples from left ventricular of 3 random rats of each group were obtained immediately at the end of anesthesia for blood analysis.The expression contents of PARP-1 protein in Cortex and hippocampus was measured by Western blot.Behavioral studies which include Hangklip-Escape Test and Open-Field Test were performed separately when the rats were 5-week-old,8-week-old and 14-week-old.Results No significant hypoxia and hypercarbon dioxide had been found in all the mice.The expression of PARP-1 protein in hippocampus area increased significantly in group E than those in group A （group A：0.32±0.53,group B：0.45±0.11,group C：0.46±0.15,group D：0.34±0.14,group E：0.80±0.34 ;P〈0.05）,while those in other brain areas had no significant differences among all groups （group A：0.34±0.07,group B：0.33±0.14,group C：0.28±0.11,group D：0.29±0.13,group E：0.38±0.15,P〉0.05）.Rats exposed to sevoflurane had longer travel distance and time than those exposed to sham anesthesia in Open-field when they were 5 weeks old （plane move time/s：group A：431±32,group B;463±27,group C：448±31,group D：467±23,group E：473±25; P〈0.05;Vertical entry time/s：group A：112±37,group B; 169±46,group C：152±44,Group D：150±26,group E：129±36;P〈0.05）,while the activity had no difference when they were 8 weeks and 14 weeks old.There was no significant difference in the Hangklip-escape test at any time.Conclusions Neonatal exposure to 2% sevoflurane for 4 h could increase the expression of PARP-1,and induce cells apoptosis in rats＇ hippocampus,therefore,it can be concluded that spatial cognition in brain was affected by sevoflurane.