麻醉药物和手术对幼龄大鼠术后空间学习记忆功能的影响

Effect of Anesthesia and Surgery on Postoperative Spatial Working Memory

目的:评价七氟烷和丙泊酚单独麻醉和与外科手术联合应用对于幼龄大鼠术后空间与学习记忆功能的影响。方法:健康雄性幼龄SD大鼠46只,连续在Morris水迷宫中训练5 d,随机分为丙泊酚组(P组)、七氟烷组(S组)、丙泊酚加手术组(PS组)、七氟烷+手术组(SS组)、对照组(C组)。P组用15 mg/kg丙泊酚诱导,50 mg/(kg·h)维持麻醉2 h;S组用4%七氟烷诱导,2%七氟烷维持麻醉2 h;C组吸入含30%氧气的空氧混合气2 h;手术为剖腹探查术。苏醒24 h后采用Morris水迷宫评价空间学习记忆功能。结果:苏醒后第1 d,P组、S组、PS组、SS组、C组大鼠在目标象限停留时间百分比分别为27.88±9.00%、29.22±8.28%、28.33±5.27%、28.17±4.22%、24.79±3.43%,其中P组、S组、PS组、SS组与C组相比,差异无统计学意义(P>0.05),P组与PS组比较、S组与SS组比较均无统计学意义(P>0.05)。且苏醒后第7 d、第30 d,P组、S组、PS组、SS组与C组相比空间探索能力的差异无统计学意义(P>0.05),P组与PS组比较、S组与SS组比较均无统计学差异(P>0.05)。结论:全凭丙泊酚和全凭七氟烷麻醉及协同腹部小手术,不改变幼龄大鼠在麻醉手术后长期的空间学习记忆功能。

Objective To investigate the differences of postoperative spatial working memory following sevo-flurane or propofol anesthesia alone and their combination with surgeries respectively in young rats. Methods After 5-day training in Morris water maze, 46 healthy male SD rats were randomly assigned to 5 groups： propo-fol group（group P）, sevoflurane group（group S）, propofol plus surgery group（group PS）, sevoflurane plus surgery group（group SS）, control group（group C）. The rats of group P were induced by intravenous injection of 15 mg/kg propofol, and anesthesia was maintained with 50 mg/（kg·h） propofol for 2 hours. 4% sevoflurane was inhaled for inducing anesthesia, and then the inhaled concentration of sevoflurane was decreased to 2% and maintained for 2 hours in group S. The rats of group C inhaled the mixture of air/oxygen （fraction of inspired oxygen, 30%） for 2 hours. The surgery was exploratory laparotomy. The spatial working memory was assessed 24 h after regaining consciousness using Morris water maze. Results The percentage of target quadrant time was 27.88 ± 9.00%, 29.22 ± 8.28%, 28.33 ± 5.27%, 28.17 ± 4.22%, 24.79 ± 3.43% respectively in group P, group S, group PS, group SS and group C. Compared with group C, the percentages of target quadrant time were not significantly declined in group P, group S, group PS and group SS（P〉0.05）, and there were no significant differences neither between group P and group PS nor between group S and group SS in day1 after regaining consciousness（P〉0.05）. Com-pared with group C ,the spatial working memory was not significantly impaired in group P, group S, group PS, group SS respectively in day 7 and day30 after regaining consciousness（P〉0.05）, and there were no significant differences neither between group P and group PS nor between group S and group SS（P〉0.05）. Conclusion Anesthesia with propofol or sevoflurane alone and their combination with minor abdominal surgery respectively did not result in impaired long-term spatial working memory in the young rats assessed by Morris water maze.