射频电磁辐射对大鼠脑组织胆碱能标志物的影响

Effects of radiation-frequency electromagnetic radiation on cholinergic neuronal markers of SD rat brain

将24只成年雄性SD大鼠按体重随机分成1组假辐照组和3组辐照组。辐照组给予全身射频电磁辐射,频率1.84 GHz、脑组织比吸收率(Specific absorption rate,SAR)分别为0.2、0.5、1.5 W/kg,连续辐照2周(5 d/周,30 min/d),照后立取SD大鼠大脑皮层和海马组织制备组织匀浆,采用化学比色法检测其胆碱能标志物水平、抗氧化物酶活性和氧化应激产物含量。结果显示:与假辐照组相比,1.5 W/kg辐照组大鼠大脑皮层内乙酰胆碱(ACh)含量和乙酰胆碱转移酶(Ch AT)活性明显降低(p<0.05),各辐照组胆碱酯酶(ACh E)的活性没有差异;各辐照组大鼠大脑皮层内超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GPX)、过氧化氢酶(CAT)的活性及丙二醛(MDA)的含量也没有明显差异;各辐照组大鼠海马组织内胆碱能标志物水平、抗氧化物酶活性和氧化应激产物均没有明显差异。结果提示,在本研究照射条件下的射频电磁辐射没有对雄性SD大鼠脑组织造成明显的氧化应激损伤,但是当SAR为1.5 W/kg时辐照能引起大鼠大脑皮层内部分胆碱能标志物水平降低。

Twenty-four male SD rats were randomly assigned to 4 groups： sham-exposure group, 0.2 W/kg exposure group, 0.5 W/kg exposure group, and 1.5 W/kg exposure group. The exposure groups were exposed to 1.84 GHz, with SAR（Specific absorption rate） of 0.2, 0.5, 1.5 W/kg for 2 weeks of 5 d/week and 30 min/d. Immediately after the last exposure, SD rats were anesthetized and executed, and then cerebral cortex and hippocampus were collected. Chemical colorimetry assay was used to detect the levels of cholinergic neuronal markers, the activity of antioxidant enzymes and the products induced by oxidative stress in cerebral cortex and hippocampus. The results showed that compared with that in the sham-exposure group, the ACh and Ch AT level of rat cerebral cortex decreased significantly in 1.5 W/kg exposure group（p〈0.05）; the ACh E level of rat cerebral cortex didn＇t show any obvious difference in exposure groups; the activity of SOD, GPX, CAT and MDA contents didn＇t change significantly in exposure groups; the level of cholinergic neuronal markers, the activity of antioxidant enzymes and the products induced by oxidative stress in hippocampus didn＇t have any significant difference in the exposure groups. The results indicate that under the present experimental setting, radiation does not cause brain damage induced by oxidative stress, and some cholinergic neuronal markers level in the cerebral cortex of SD rat decrease in 1.5 W/kg exposure group.