三碘甲腺原氨酸对新生小鼠兴奋毒性脑损伤病理改变及Caspase-3和髓鞘碱性蛋白表达的影响  

Effect of Triiodothyronine on Brain Pathological Lesion and Expressions of Caspase-3 and Myelin Basic Protein after Excitotoxic Brain Injury in Neonatal Mice

作　　者：许小艳[1] 贺湘英[1] 段江[1] 莫亚雄[1] 李琪[1] 肖群文[1] 梁琨[1] 

机构地区：[1]昆明医学院第一附属医院儿科,昆明650032

出　　处：《实用儿科临床杂志》2011年第13期1015-1018,共4页Journal of Applied Clinical Pediatrics

基　　金：云南省自然科学基金(2004C0019R)

摘　　要：目的探讨腹腔注射不同剂量三碘甲腺原氨酸(T3)对新生小鼠兴奋毒性脑损伤脑组织病理改变和Caspase-3、髓鞘碱性蛋白(MBP)表达的影响。方法 72只新生5日龄(P5)ICR小鼠随机分为PBS对照组(PBS组)、兴奋毒性脑损伤模型组(IA组)、T3低剂量治疗组(LT组)、T3中剂量治疗组(MT组)和T3高剂量治疗组(HT组)。模型组及T3各剂量治疗组脑内注射鹅膏蕈氨酸建立兴奋毒性脑损伤模型,模型建立后腹腔注射3种不同剂量(2μg.kg-1、5μg.kg-1、10μg.kg-1)T3共5 d干预治疗。于脑内注射后120 h(P10)、30 d(P35)各取6只小鼠处死,HE染色观察其脑组织病理改变。免疫组织化学法检测小鼠脑组织损伤区Caspase-3及MBP的表达。结果 P10时,MT组脑白质及皮质损伤较IA组均明显减轻(Pa<0.01),HT组脑皮质损伤较IA组减轻(P<0.05);IA组Caspase-3表达较PBS组明显增强(P<0.001),MT组和HT组Caspase-3表达与IA组比较明显减低(P<0.01);P10和P35时,IA组MBP表达较PBS组均明显减弱(P<0.001),MT组和HT组MBP表达较IA组均明显增强(P<0.05)。LT组脑组织病理损伤程度及Caspase-3、MBP表达与IA组比较差异均无统计学意义(Pa>0.05)。结论腹腔注射中剂量及高剂量T3可减轻小鼠兴奋毒性脑损伤病理损伤程度,减少细胞凋亡,促进髓鞘的形成;低剂量T3对新生小鼠兴奋毒性脑损伤程度、细胞凋亡及髓鞘形成均无影响。Objective To determine the changes in pathological lesion of the brain and the expressions of Caspase-3 and myelinbasicprotein（MBP）,explore the neuroprotective function of different dose triiodothyronine（T3） on excitotoxic brain injury in neonatal mice.Methods Seventy-two 5 day-old institute of cancer research（ICR）-type neonatal mice were randomly divided into 5 groups： PBS control group（PBS group）,model group with excitotoxic brain injury（IA group）,low-dose T3 treated group（LT group）,middle-dose T3-treated group（MT group）,and high-dose T3 treated group（HT group）.The models of excitotoxic brain injury were established by injecting ibotenic acid into the right hemisphere（intracranially）,and the excitotoxic model received intracerebral injection,and the T3 treated groups were given intraperitoneal injections at 1 h,24 h,48 h,72 h and 96 h with different doses（2 μg·kg-1,5 μg·kg-1,10 μg·kg-1） T3 after intracerebral injection respectively.Six mice in each group were sacrificed at 120 h（P10） and 30 d（P35） after intracerebral injection,their brains tissues were removed,the extent of the brain lesion in each group were calculated through the numbers of the pathological slides with brain injury,and immunohistochemical technique was applied to detect the changes in expressions of Caspase-3 and MBP.Results The size of brain pathological lesion in MT group was significantly smaller（Pa0.01）;the size of cortical plate lesion in HT group was also significantly smaller（Pa0.05）,but the expression of Caspase-3 in IA group was significantly enhanced compared with that in PBS group（P0.001）;The expression of Caspase-3 in the MT group and the HT group were greatly decreased compared with that in the IA group（P0.01）.At P10 and P35,the MBP expressions in IA group decreased significantly compared with that in PBS group（P0.001）;the MBP expressions in the MT group and the HT group were greatly increased compared with that in the IA group（P0.05）.There were no st

关 键 词：三碘甲状腺原氨酸 兴奋毒性 脑损伤 半胱氨酸天冬酶-3 髓鞘碱性蛋白 

分 类 号：R722.6[医药卫生—儿科]