连续低剂量X线照射对孕鼠子代海马CA1区锥体细胞增殖的影响  

The effect of continuous low doses X-ray on the proliferation of pyramidal cell in hippocampus CA1 in prenatal rats

作　　者：张炜[1] 王培军[1] 姜文霞[2] 董宁欣[1] 李铭华[1] 张静[1] 江虹[1] 陈双庆[1] 高晓龙[1] 

机构地区：[1]同济大学附属同济医院医学影像科,上海200065 [2]同济大学医学院病理教研室

出　　处：《中华预防医学杂志》2010年第7期596-601,共6页Chinese Journal of Preventive Medicine

摘　　要：目的探讨孕期连续受低剂量X线照射对子代Sprague-Dawley大鼠海马回1区（CA1）锥体细胞增殖的影响，并揭示造成影响的相关机制。方法确定受孕SD大鼠25只，抽签法随机分为4个实验组（H组、M组、LI组及12组，分别接受0．09mGy／d、0．06mGy／d、0．03mGy／d、0．015mGy／d剂量的X线照射，照射18d，无间隔）及对照组（C组，接受假照射），每组5只，仔鼠分组同孕鼠。通过HE染色、Envision免疫组织化学法及图像处理系统对大鼠海马CA1区锥体细胞形态学进行观测（锥体细胞层次宽度及细胞密度变化）及胞质内细胞外信号反应激酶（ERK）1和（或）ERK2蛋白表达的检测。结果（1）孕期连续受到低剂量X线照射可以促进子代海马CA1区锥体层次宽度的增加，H组、M组、L1组及L2组的锥体层次宽度（像素）分别为129．620±38．491、116．217±1．161、118．343±20．916、122．066±13．036，高于C组（89．797±3．919），差异有统计学意义（F值分别为8．475、33．42、14．395、44．955；p值分别为0．002、0．048、0．030、0．012）；但H组锥体细胞排列稀疏、松散，单位面积锥体细胞密度低于其他各组（0．1249±0．0246），差异有统计学意义（F值为4．466，P值为0．017）。（2）L1组、L2组大鼠海马CAl区ERK1和（或）ERK2阳性细胞平均吸光度值（A值）（0．3082±0．0240、0．3125±0．0412）高于C组（0．2457-t-O．0694），差异有统计学意义（F值分别为4．561、4．103，P值分别为0．044、0．035）；M组及H组阳性细胞A值分别为0．2287±0．0228和0．2326±0．0331，与对照组相比较差异无统计学意义（F值分别为0．326、0．174，P值分别为0．888、0．951）。结论孕期连续受到低剂量X线照射可以促进子代海马CAl区锥体细胞发生增殖性改变，这一作用可能是通过促进细胞内ERK1和（或）ERK2蛋白表达增加来实现的，达到一定剂量时�Objective To explore the effect of low doses X-ray on proliferation of hippocampal pyramidal cell in the area of CA1 in prenatal rat and its relevant mechanism Methods A total of 25 pregnant rats were randomly divided into four experimental groups and one control group. The experimental groups,in a duration of consistent 18 days, respectively received different doses as follows： 0. 015 mGy/d, 0. 03 mGy/d, 0. 06 mGy/d and 0. 09 mGy/d. The control group received sham radiation. To observe the density and width of hippocampal pyramidal cell in the aera of CA1 by HE stained and observe the expression of the ERK1/2 by IHM. Results （ 1 ） Except C group, all other groups presented increment in width of the level of hippocampal pyramidal cell, compared with C group ; H group, M group, L1 group and L2 group were higher than that （ F value respectively were 8.475,33.42, 14. 395,44. 955 ; P value respectively were 0. 002,0. 048,0. 030,0. 012）. But the phenomenon of inhomogeneity in width in H group was observed, at the same time,the density of cell in H group became looser（ F =4. 466,P =0. 017）. （2） The expression of ERK1/2 in the hippocampus CA1 was seen in cytoplasm of every group, the average optical density of positive ERK1/2 protein significantly increased in L1 group and L2 group, compared with control group respectively （ F value respectively were 4. 561,4. 103,P value respectively were 0. 044,0. 035）. Conclusion Low doses X-ray could promote proliferation of hippocampus CA1 cell in prenatal. The reason could be the increment of the ERK1/2 protein induced by X-ray. When the doses reached 0. 09 mGy/d, the excessed proliferation phynomenon was observed.

关 键 词：辐射 电离 大鼠 SPRAGUE-DAWLEY 海马 锥体细胞 

分 类 号：R714.2[医药卫生—妇产科学]