X线照射对实验性癫痫大鼠脑皮层谷氨酸、c-fos和GS的影响

目的探讨癫痫大鼠放射治疗中兴奋性氨基酸递质谷氨酸的含量及其主要的代谢酶GS和c-fos蛋白的在抗痫中的作用机制及合理放射剂量。方法利用慢性点燃癫痫大鼠进行0、24、12、6 Gy的X线放射,用氨基酸分析仪测定不同照射剂量癫痫大鼠及照射后1 h、24 h、1周时癫痫大鼠额叶皮层内的谷氨酸含量变化,利用免疫组织化学的方法观察抗GS和c-fos蛋白阳性细胞率。结果12 Gy、24 Gy组较对照组Glu含量低,GS含量增高,而c-fos在6～24Gy放射后均有减少,但以12 Gy、24 Gy组明显,照射后1 h、24 h、1周后与对照组间有GS的进行性增高,Glu含量在照射后1 h和1周含量较对照对下降,c-fos的下降仅出现在1 h组。结论放射治疗癫痫主要是早期通过发生c-fos和Glu变化产生抗痫作用,长期作用可能与GS和Glu有关;癫痫大鼠接受12 Gy的放射治疗较为合理。

Effect of X-ray on Glutamate, c-fos and GS in Brain of Epileptic Rat

Objective To investigate the effective mechanism of glutamate, GS and c - fos in radiotherapy of epileptic rat, and find rational dose of radiotherapy of epilepsy. Methods To make rat model of epilepsy and give 0, 24,12 or 6 Gy X ray irradiation, and measure content of Glu , by amino acid analyzer, and GS and e-fos changes, by immunohistoehemieal, in frontal lobe of those rats in lhour, 24 hours or 1 week after radiotherapy. Results There were low glutamate and high GS in frontal lobe of rat, after 12 Gy or 24 Gy irradiation, and there were low c-fos after 6 - 24 Gy irradiation. C-fos protein decreased in 1 hour after irradiation and GS improved continually from 1 hour to 1 week, and glutamate decreased in 1 hour and 1 week. Conclusion Radiotherapy of epileptic rat give effect by c-fos and glutamate in early stage and glutamate and GS in last time 12 Gy may bethe rational radio dose for epileptic rat.