反复注射异丙酚对新生大鼠认知功能的影响

目的 探讨反复注射异丙酚对新生大鼠认知功能的影响.方法 清洁级SD大鼠24只,7 d龄,12～16 g,雌雄各半,随机分为3组(n=8):对照组(C组)腹腔注射生理盐水7.5 ml/kg,1次/d,连续7 d;单次注射异丙酚组(P1组)腹腔注射生理盐水7.5 ml/kg,1次/d,连续6 d,第7天腹腔注射异丙酚75 mg/kg;反复注射异丙酚组(P2组)腹腔注射异丙酚75 mg/kg,1次/d,连续7 d.异丙酚给药结束后2周时采用水迷宫实验测试学习记忆功能,然后断头处死大鼠,取脑组织,采用高效液相色谱法测定皮层和海马谷氨酸、天冬氨酸、甘氨酸和7.氨基丁酸的含量.结果 与C组和P1组比较,P2组认知功能下降,海马天冬氨酸含量降低,皮层和海马谷氨酸含量降低,谷氨酸/γ-氨基丁酸比值下降(P＜0.05),皮层和海马甘氨酸和γ-氨基丁酸含量差异无统计学意义(P＞0.05).结论 反复注射异丙酚可导致新生大鼠远期认知功能减退,可能与脑内兴奋性氨基酸递质含量的降低有关.

Effects of multiple doses of propofol on cognitive function in neonatal rats

Objective To investigate the effects of multiple doses of propefol on long-term cognitive function in neonatal rats.Methods Twenty-four 7-day old SD rats weighing 12-16 g were randomly divided into 3 groups(n=8 each):group Ⅰ control(C)received intraperitoneal(IP)normal saline(NS)7.5 ml/kg once a day × 7 days:groupⅡ propofol 1(P1)received NS 7.5 ml/kg IP once a day×6 days+propofol 75 mg/kg IP on the 7 th day and group Ⅲ propofol 2(P2)received propefol 75 mg/kg IP once a day × 7 days.Learning and memory function were assessed using Morris water maze when the rats were 4 weeks old.The animals were decapitated immediately after the tests.The cortex and hippocampus were isolated for determination of aspartate (Asp),glutamic acid(Glu),glycine(Gly)and γ-aminobutyric acid(GABA)contents using high performance liquid chromatography(HPLC).Results Long-term learning and memory function significantly declined in group P2 as compared with group C and P1.The content of Asp in hippocampus and the Glu content and Glu/GABA ratio in cortex and hippocampus were significantly lower in group P2 than in group C and P1.There was no significant difference in Gly and GABA content in cortex and hippocampus among the 3 groups.Conclusion Multiple doses of propefol decreases long-term cognitive function by decreasing the levels of excitatory amino acid transmitters in the brain in neonatal rats.