间断低剂量电离辐射对慢性脑缺血大鼠认知功能影响的研究

Effects of intermittent low dose radiation on cognition of chronic cerebral hypoperfusion rat

目的观察间断低剂量电离辐射对慢性脑缺血(CCH)大鼠认知功能的影响。方法SD大鼠随机分为2组:缺血组和缺血+X线组。两组均采用双颈总动脉结扎建立模型,缺血+X线组大鼠于模型建立1w后接受间断X线全身照射,0.5Gy.w^-1×3w。Moms水迷宫评估2组大鼠空间学习能力;取2组大鼠海马组织,免疫组化比较Caspase-3的含量,Western blot比较IL-6和TNF-α的含量,ELESA比较丙二醛(MAD)含量和超氧化物歧化酶(SOD)的活性。结果3次间断0.5Gy的X线照后,2组大鼠平均逃避潜伏期和平均通过平台次数无差异,但缺血+X线组大鼠海马组织Caspase-3、IL-6和TNF-α的含量较慢性缺血组减少,两组间MAD含量和SOD活性无显著性差异。结论3次间断低剂量的电离辐射并不影响CCH大鼠的认知功能,但能降低大鼠海马组织凋亡蛋白和炎性因子的含量,需要观察更多次低剂量电离辐射对CCH大鼠认知功能影响的研究。

Objective To investigate the effects of intermittent low dose radiation on cognition of chronic cerebral hypoperfusion(CCH)rat.Methods SD rats were randomly divided into 2 groups:CCH group and CCH+X radiation group.CCH model was made by permanent ligation of bilateral carotid artery.1 week later,Rats of CCH+X group were exposed to whole-body X radiation,0.5Gy each time,once a week,for 3 weeks.Then spatial learning and memory was measured in the Morris water maze test.Hippocampal of two groups were extracted.Caspase-3 level were measured by immunohistochemical staining,IL-6 and TNF-α levels were measured by western blotting analysis,MAD and SOD levels were measured by enzyme-linked immunosorbent assay.Result After 3 times X radiation,there were no difference between two groups in escape latency and the frequencies of crossing the original platform.But there are significant decrease of Caspase-3,IL-6 and TNF-α levels in CCH+X radiation group hippocampal,compared with CCH group.MAD and SOD levels have no difference between two groups.Conclusion 3 times inteimittent low dose X irradiation doesn,t affect the cognition of CCH rat,But can decrease the levels of apoptosis protein and inflammation factors.The effects of more times intermittent low dose radiation on cognition of CCH rats is warrant.