手术创伤及多次丙泊酚麻醉对发育期大鼠神经发育和认知功能的影响

目的：探讨手术创伤及多次丙泊酚麻醉对发育期大鼠神经发育和认知功能的影响及相关机制。方法：104只13日龄SD大鼠随机分为4组：空白对照组、丙泊酚组、手术组、丙泊酚+手术组，每组26只。空白对照组连续5?d腹腔注射等渗氯化钠溶液7.5?mL·kg^–1·d^–1，丙泊酚组连续5?d腹腔注射丙泊酚75?mg·kg^–1·d^–1，手术组行罗哌卡因局麻下剖腹探查术，后续4?d腹腔注射等渗氯化钠溶液7.5?mL·kg^–1·d^–1，丙泊酚+手术组大鼠接受腹腔丙泊酚注射75?mg/kg后，罗哌卡因局麻下行剖腹探查术，随后4?d连续腹腔注射丙泊酚75?mg·kg^–1·d^–1。术后各组随机分为两个亚组。其中一个亚组造模完成后1?d检测海马组织中肿瘤坏死因子α（TNF-α）的浓度以及caspase-3、c-fos的表达，TUNEL检测观察新生鼠海马组织中神经元凋亡情况。另一亚组饲养至第60天时行莫里斯水迷宫实验评估大鼠认知功能，然后检测大鼠海马组织中TNF-α的浓度及caspase-3、c-fos的表达水平，TUNEL检测观察大鼠海马组织中神经元凋亡情况。结果：造模完成后1?d结果显示，与空白对照组比较，其他三组海马组织中TNF-α含量显著升高，caspase-3、c-fos表达增加，海马组织神经元凋亡数量增多（均P<0.05）；与手术组比较，丙泊酚组和丙泊酚+手术组海马组织TNF-α含量增加，caspase-3、c-fos表达增加，海马神经元凋亡数量增加（均P<0.05），但丙泊酚组及丙泊酚+手术组两组间差异无统计学意义（均P>0.05）。莫里斯水迷宫实验结果表明，各组间游泳速度、登台潜伏期、目标象限停留时间和穿台次数差异无统计学意义（均P>0.05）。水迷宫实验后测定海马组织TNF-α浓度、caspase-3、c-fos的表达及海马神经元凋亡数量结果发现各组大鼠间差异无统计学意义（均P>0.05）。结论：新生大鼠接受局麻腹部手术和多次丙泊酚麻醉可引起中枢炎症介质释放增多，海马神经元凋亡增加，但该损伤对大鼠远期神经发育及认知功能无明显影响。

Effect of operative trauma and multiple propofol anesthesia on neurodevelopment and cognitive function in developmental rats

Objective: To investigate the effect of multiple propofol anesthesia and operative trauma on neuroinflammation and cognitive function in development rats and its mechanism. Methods:A total of 104 13-day-old neonatal Sprague-Dawley rats were randomly divided into 4 groups with 26 rats in each group: control group was treated with7.5?mL/kg saline q.d for 5?d, propofol group was treated with 75?mg/kg propofol q.d for 5?d,surgery group received abdominal surgery under local anesthesia and then treated with7.5?mL/kg saline q.d for 4?d, surgery with propofol group received 75?mg/kg propofol anesthesia plus abdominal surgery under local anesthesia with ropivacaine at d1, then treated with 75?mg/kg propofol q.d for 4?d. At d2 of experiment, 13 rats from each group were sacrificed and brain tissue samples were taken, the concentration of TNF-α in hippocampus was detected with ELISA, the expression of caspase-3 and c-fos in hippocampal tissue was determined with immunohistochemical method, the number of apoptotic neurons in hippocampus was examined with TUNEL assay. Morris water maze test was used to examine the cognitive function of the rest rats at the age of 60?d, and the TNF-α concentration, caspase-3, c-fos expressions and the number of apoptotic neurons in hippocampus were also detected. Results: Compared with control group, TNF-α concentration, caspase-3, c-fos expression and the neuroapoptosis in hippocampus increased significantly in other three groups (all P<0.05). Compared with surgery group, propofol group and surgery with propofol group showed increased TNF-α level, caspase-3 and c-fos expressions and apoptotic cell numbers (allP<0.05), but there was no significant difference between last two groups (allP>0.05). Morris water maze test showed that there were no significant differences in swimming speed, escape latency, target quadrant residence time and crossing times among groups (allP>0.05). TNF-α level, expressions of caspase-3 and c-fos and apoptotic cell numbers in hippocampus had no significant differences among the 4 adult rats groups (allP>0.05).Conclusion: Abdominal surgery and multiple propofol treatment can induce neuroinflammation and neuroapoptosis in hippocampus of neonatal rats, however, which may not cause adverse effects on neurodevelopment and cognitive function when they grown up.