电离辐射对大鼠脑皮质牛磺酸、谷氨酸及其谷氨酸阳性神经元的影响

目的 探讨电离辐射对大鼠脑皮质内谷氨酸(glutamate,Glu)、牛磺酸(taurine,Tau)水平和谷氨酸阳性神经元的影响。方法 雄性SD大鼠45只随机分为3组,头部分别给予0、10、20 Gy ⁶⁰Coγ射线照射。照射后12h测定脑皮质谷氨酸(Glu)、牛磺酸的含量以及神经细胞内游离Ca²⁺浓度([Ca²⁺]i),同时观察大鼠脑皮质Glu阳性神经元以及神经细胞凋亡情况。结果 随着照射剂量的增加,脑皮质内Glu含量升高,Tau含量减少,Glu/Tau比值逐渐上升,细胞内游离Ca²⁺浓度([Ca²⁺]i)升高,Glu阳性神经元数量增加,细胞凋亡数量上升,并与电离辐射呈一定的量效关系。结论 上述结果提示Glu产生的神经毒作用参与了电离辐射对中枢神经系统的损伤过程。

Changes of Tau , Glu and Glu-positive Neurons in Cerebral cortex of Rats after Ionizing Irradiation

Objective To study the alterations of Tau, Glu and Glu-positive neurons in cerebral cortex of rats after ionizing irradiation.Methods 45 SD rats were randomly divided into three groups, the rats were irradiated on the brain with 0, 10 and 20 Gy by ⁶⁰Coγ-ray respectively.After 12h, the levels of Tau and Glu were measured and the alterations of Glu-positive neurons and apoptosis were observed in rat cerebral cortex.Results After irradiated, the content of Tau was decreased and the content of Glu was increased in the rat cerebral cortex, and the ratio of Glu/Tau were went up significantly.The amount of Glu-positive neurons and apoptosis were augmented in the rat cerebral cortex in a dose-effect manner.Conclusion Under ionizing irradiation brain injury, the changes of Glu coincides with the apoptosis in cerebral cortex.Our study indicate that neuro-toxin of Glu might play an important role in mechanism of ionizing irradiation brain injury.