异氟烷预处理对电磁脉冲辐射所致脑损伤的保护作用研究

Effect of Isoflurane Preconditioning on EMP induced Brain Injury

目的:探讨异氟烷预处理对电磁脉冲辐射所致脑损伤的保护作用。方法:选取成年雄性SD大鼠48只,采用随机数字表法,将其随机分为4组(n=12),分别为:假辐照组(CON组)、电磁辐照组(EMP组)、异氟烷预处理组(IP组)和异氟烷预处理+电磁辐照组(IP+EMP组)。EMP组场强为400 KV/m,脉冲为200次,连续辐照3天;IP组吸入2.0%异氟醚2h;IP+EMP组吸入2.0%异氟醚2 h,24 h后制备EMP损伤模型。于辐照后24 h处死大鼠,每组随机抽取3只大鼠,取脑组织,采用ELISA法检测大鼠海马IL-6和TNF-α的表达变化;尼氏染色法观察大鼠海马区神经元的凋亡;采用Western blot法检测大鼠海马区BDNF蛋白的表达情况;采用免疫荧光法检测大鼠海马区BDNF细胞水平的表达。结果:与CON组比较,EMP组、IP组、IP+EMP组的IL-6和TNF-α的表达增高,尼氏小体减少,BDNF蛋白及细胞水平的表达均下调(P<0.05);与EMP组比较,IP组和IP+EMP组IL-6和TNF-α的表达降低,尼氏小体增多,BDNF蛋白及细胞水平的表达上调(P<0.05)。结论:异氟烷预处理可减轻电磁脉冲辐射所致脑损伤,其机制可能与减轻大鼠炎症反应有关。

Objective： To investigate the effect of isoflurane preconditioning on EMP induced cognitive impairment. Methods：Forty-eight healthy male SD rats, aged 3 months, weighing 250-280 g, were randomly divided into four groups（ n=12）： CON group,EMP group, isoflurane preconditioning group（ IP group） and IP＋EMP group. In groups EMP and IP＋EMP, the animals were exposed or not to 200 pulses of EMP at 400 k V/m and continuous for 3 days. In group IP＋EMP, the animals in haled 2.0% isoflurane for 2 h, and electromagnetic radiation was performed at 24 h after the end of preconditioning. The rats were sacrificed at 24 h after irradiation. Three rats in each group were randomly selected to take the brain tissue, and the expression of IL-6 and TNF-α were detected by ELISA method; Nissl staining method was used to observe the nissl body of hippocampal in rats. The hippocampal was removed for detection of the expression of BDNF protein by Western blot analysis.BDNF was detected in the hippocampal using immunofluorescence. Results：Compared with CON group, the expression of IL-6 and TNF-α in the EMP group, IP group and IP＋EMP group were increased, the Nissl bodies were reduced, the expression of BDNF protein and cell level were down regulated（P〈0.05）. Isoflurane preconditioning significantly reduced the expression of IL-6 and TNF-α and increased the Nissl bodies, and up-regulated the expression of BDNF protein and cell level（P〈0.05）. Conclusion： Isoflurane preconditioning can reduce cognitive impairment induced by EMP, and its mechanism may be related to the reduction of inflammatory response in rats.