三碘甲状腺原氨酸对兴奋毒性脑损伤模型小鼠学习记忆行为的影响  

Effects of triiodothyronine on the learning and memory behaviors in neonatal mice following excitotoxic brain damage

作　　者：伍根峰[1] 贺湘英[1] 李琪[1] 徐静[1] 肖群文[1] 齐志业[1] 梁琨[1] 

机构地区：[1]昆明医学院第一附属医院儿科,云南昆明650032

出　　处：《中国当代儿科杂志》2010年第4期284-286,共3页Chinese Journal of Contemporary Pediatrics

基　　金：云南省自然科学基金(2004C0019R)

摘　　要：目的有研究表明甲状腺功能减退大鼠学习、记忆功能的损伤与神经元局部三碘甲状腺原氨酸(triiodothyronine,T3)缺乏有关。该研究探讨左旋三碘甲状腺原氨酸(L-T3)对新生小鼠兴奋毒性脑损伤后学习、记忆行为的影响。方法5日龄ICR种小鼠71只,用鹅膏蕈氨酸(ibotenicacid,IA)建立兴奋毒性脑损伤模型,随机分为磷酸盐缓冲液(PBS)组(n=14,脑内及腹腔注射PBS10mL/kg)、IA组(n=14,脑内注射IA+腹腔注射PBS10mL/kg)、低剂量T3组(n=14,脑内注射IA+腹腔注射L-T30.2μg/kg)、中剂量T3组(n=15,脑内注射IA+腹腔注射L-T30.5μg/kg)、高剂量T3组(n=14,脑内注射IA+腹腔注射L-T31μg/kg)。腹腔注射时间为小鼠脑内注射后1、24、48、72、96h。小鼠于生后第33、34天进行Y-迷宫分辨学习实验。结果PBS组、IA组、低、中、高剂量L-T3组小鼠学会所需次数分别为15.0±4.7、21.3±6.3、20.5±6.0、21.0±6.5、15.8±4.5,高剂量L-T3组小鼠"学会"所需次数明显低于IA组和中、低剂量L-T3组(P<0.05);记忆正确率分别为(90.7±7.3)%、(79.3±10.0)%、(77.9±14.2)%、(80.7±12.2)%、(91.4±9.5)%,高剂量L-T3组小鼠记忆正确率明显高于IA组和中、低剂量L-T3(P<0.05)。结论高剂量L-T3(1μg/kg)能促进兴奋毒性脑损伤小鼠的学习记忆行为。Objective Some research has shown that learning and memory function impairments in rats with hypothyroidism are associated with triiodothyronine （T3） deficiency in neurons.This study aimed to investigate the effects of L-T3 administration on learning and memory behaviors in neonatal mice with excitotoxic brain damage.Methods Seventy-one 5-day-old ICR neonatal mice were randomly assigned to five groups：controls that received intracerebral and intraperitoneal injections of phosphate buffered saline （PBS） （n=14）;a group that received intracerebral injections of ibotenic acid （IA） and intraperitoneal injection of PBS （n=14）;3 groups that received intracerebral injections of IA and intraperitoneal injection of L-T3 at 0.2,0.5,and 1 μg/kg,respectively （n=14-15）.Intraperitoneal injections were done 1,24,48,72 and 96 hrs after intracerebral injections.Learning and memory functions were evaluated by the Y-maze discrimination learning test on postnatal days 33-34.Results The learning and memory functions in the highest L-T3 dose group were significantly better than those in the IA,and the lower L-T3 dose groups,presenting with decreased number of trials to criterion [15.8±4.5 vs 21.3±6.3 （IA group）,20.5±6.0 （0.2 μg/kg L-T3 group） or 21.0±6.5 （0.5 μg/kg L-T3 group）;P0.05],and achieving a higher correct percentage [91.4±9.5% vs 79.3±10.0% （IA group）,77.9±14.2% （0.2 μg/kg L-T3 group） or 80.7±12.2% （0.5 μg/kg L-T3 group）;P0.05].Conclusions High-dose L-T3 （1 μg/kg） may improve learning and memory functions in mice following excitotoxic brain damage.

关 键 词：三碘甲状腺原氨酸 鹅膏蕈氨酸 兴奋毒性 脑损伤 新生小鼠 

分 类 号：R722.6[医药卫生—儿科]