谷氨酸氧化毒性在脑外伤后继发性脑损伤中作用的实验研究

目的 用大鼠脑外伤模型研究谷氨酸氧化毒性在脑外伤后继发性脑损伤中的作用.方法 用自由落体致伤的方法制作大鼠重型颅脑外伤模型,D609为治疗药物;SD大鼠按随机数字表法分为对照组、外伤组和治疗组,各组内均分为三组,分别检测实验性外伤后24h的脑皮质谷胱苷肽(GSH)含量、脑组织含水量、神经元凋亡情况.结果 治疗组伤侧皮质GSH含量显著高于外伤组(P<0.01),但显著低于对照组(P<0.01);治疗组脑水肿显著低于外伤组(P<0.01),但显著高于对照组(P<0.01);脑组织TUNEL染色显示,外伤组伤侧海马见大量凋亡细胞,治疗组伤侧海马凋亡细胞明显减少,显著低于外伤组(P<0.01),外伤组及治疗组对侧海马和对照组海马均未见凋亡细胞.结论 谷氨酸氧化毒性是引起大鼠颅脑外伤后继发性脑损伤的重要机制.

Role of oxidative glutamate toxicity in secondary brain injury following brain trauma

Objective To study the contribution of oxidative glutamate toxicity in rat brain after experimental traumatic brain injury. Methods The brain injury of the rats was induced with a free dropping impact. Seventy-two male SD rats were randomly divided into three groups: control group, traumatic group and D609 treatment group. D609 was administered via intracerebroventricular infusion 30min before brain trauma. 24h post-injury, water content and glutathione (GSH) concentration were evaluated, and histopathological changes were observed. Results GSH levels in D609 treatment group were significantly lower than that of control group (P<0.01), but significantly higher than that of traumatic group (P<0.01). Compared with traumatic group, brain water content in D609 treated rats was decreased obviously (P<0.01), but was remained higher than that of control group (P<0.01). TUNEL staining showed that most neurons were TUNEL-positive in the injured hippocampus in traumatic group, but less were observed in D609 treatment group, and few were found in control group. Conclusion Oxidative glutamate toxicity is one of the important mechanisms involved in secondary brain injury following brain trauma, and contributes a lot to the injury.