实验性癫痫磁共振波谱与病理学对照研究

Comparative study of MRS and pathology in epilepsy model of rat

目的 观察氢质子磁共振波谱 (1HMRS)检测的致癫痫灶中某些异常代谢产物及其产生的病理学基础。方法 选取 2 1只Wistar大鼠 ,用 10 %毛果芸香碱 35 0mg/kg经腹腔注射 ,诱发反复、全面的强直阵挛发作 ,并制成癫痫持续状态 (statusepileptics ,SE) ,按发作持续时间不同分 4组 ,其中 6只为对照组 ,15只为实验组。光学显微镜下观察颞叶、海马区病理学变化 ,并用 9 4T磁共振波谱仪检测离体状态脑代谢产物N 乙酰天门冬氨酸 (NAA)、胆碱 (Cho)、乳酸 (Lac)、γ 氨基丁酸 (GABA)相对含量的变化。用方差分析和等级相关进行统计学分析。结果 SE 0 5h内 ,光镜观察到颞叶、海马区神经元变性、少许丢失 ,与对照组相比 ,1HMRS检测到NAA轻度降低 (0 80± 0 0 6 ,P <0 0 5 ) ,Cho、Lac、GABA值无变化 ;SE 3h ,神经元坏死、丢失明显 ,少许胶质增生 ,除NAA降低外 ,Lac值开始升高 (3 84± 0 98,P <0 0 5 ) ,SE 6～ 6 0h ,神经元坏死、丢失及胶质增生严重 ,除NAA、Lac值变化外 ,还观察到Cho值升高 (1 13± 0 0 3,P <0 0 5 )和GABA值降低 (1 0 1± 0 2 3,P <0 0 5 )。NAA值与癫痫持续时间呈显著负相关 (γs=- 0 78,P <0 0 1) ,与海马CA1区和CA3区神经元数量呈显著正相关 (γs=0 79,P <0 0 1)。结论 1HMRS检?

Objective To study abnormalities of metabolites with 1H MRS and their pathological basis in epileptic rats Methods Fifteen Wistar rats were injected with 10% pilocarpine intraperitoneal to induce generalized tonic clonic seizure(GTCS)and status epileptics(SE) Six rats were used as control According to the duration of GTCS, the epileptic rats were divided into 4 groups At different times of GTCS, the temporal lobes and hippocampus were taken out for histological study with light microscopy(HE staining) and 1H MRS(9 4 T) examination was done in vitro to measure the concentrations of N acetylaspartate (NAA), lactate (Lac), choline (Cho), and γ aminobutanoic acid (GABA) Variance analysis and rank correlation were used for statistical analysis Results After 0 5 hour of SE, neuronal degeneration and some neuronal loss were detected with light microscopy NAA concentration decreased slightly(0 80±0 06, P <0 05), Lac, Cho, and GABA remained unchanged compared with the control After 3 hours of SE, neuronal necrosis and slight gliosis were found Besides the decrease of NAA , increase of Lac was also found on 1H MRS (3 84± 0 98) From 6 to 60 hours of SE ,severe neuronal necrosis and gliosis were detected Besides the change of NAA and Lac, increased Cho (1 13± 0 03, P <0 05) and decreased GABA (1 01± 0 23, P <0 05) were also detected NAA was correlated with SE lasting time negatively(γ s =-0 78, P <0 01),and with number of neurons of CA1 and CA3 positively(γ s=0 79, P <0 01) Conclusion NAA is the most sensitive marker of early brain damage decreased NAA correlate with prolongation of seizure time and loss of neurons; the change of Lac reflected moderate to severe injury of neurons; Increase in Cho may represent gliosis;decreased GABA can be detected when neuronal damage becomes severe