【摘要】 目的研究伽玛刀照射对癫痫大鼠的放射生物学作用,探讨伽玛刀治疗癫痫的作用机制。方法利用海人酸制备癫痫大鼠模型50只(癫痫组25只,伽玛刀照射组25只),对照组为正常大鼠25只(注射生理盐水),观察各组行为学改变;采集伽玛刀照射后1d、1w、2w、4w、8w后各组大鼠海马细胞外液,并测定Glu和GABA含量及观察海马超微结构变化。结果 1w后,照射组和癫痫组GABA含量均低于对照组;2w后,照射组和癫痫组Glu含量均高于对照组;4w后,照射组Glu含量低于癫痫组,GABA含量高于癫痫组;差异均具有统计学意义(P<0.05)。海马组织超微结构显示照射组早中期与癫痫组基本一致,其晚期部分结构恢复,线粒体修复较为明显。结论伽玛刀照射可调节海马中Glu与GABA以达到新的平衡,并在癫痫发作引起的病理性损伤修复中起到重要作用。更多还原

【Abstract】 Objective To analyze the radiobiological effect of gamma knife surgery(GKS) on epileptic rat and the treatment mechanism of GKS for epilepsy.Methods Kainic acid was used in 50 rats to develop epilepsy model which were randomly divided into two groups(1st group of epileptic model under observation,n=25;2nd group of epileptic model for GKS treatment,n=25) and another 25 rats were injected with physiological saline in hippocampus as a control group(3rd group) to study the behavior changes of the three groups.Extracellular fluid of rat hippocampus was extracted at 1 day,1 week,2 weeks,4 weeks and 8weeks after GKS by brain microdialysis.Reversed-phase high performance liquid chromatography analysis was performed to determine the changes of glutamic acid(Glu) and gamma-aminobutyric acid(GABA) in rat hippocampus of different groups.Ultramicrostructure changes of hippocampus were observed with electric microscopy.Results At 1 week,GABA content of rats’ hippocampus of 1st and 2nd groups was lower than that of 3rd group;at 2 weeks,Glu content of 1st and 2nd groups was higher than that of 3rd group;at 4 weeks,Glu and GABA content of 2nd group were lower and higher respectively than that of 1st group,and all the differences were statistically significant(P<0.05).Observation of ultramicrostructure of hippocampus showed that the changes of 1st and 2nd groups at early and mid stages were accordant,however,the ultramicrostructure of 2nd group recovered partially at later period with obvious repair of mitochondria.Conclusion GKS can regulate the content of Glu and GABA of hippocampus to achieve a new balance of the two transmitters and inhibition of epileptic episode,meanwhile,substantially contribute to the pathological repair of damage resulting from epileptic episode.更多还原