中华放射医学与防护杂志
中華放射醫學與防護雜誌
중화방사의학여방호잡지
Chinese Journal of Radiological Medicine and Protection
2014年
3期
164-167
,共4页
刘兵%孔博玉%马淑梅%刘晓冬
劉兵%孔博玉%馬淑梅%劉曉鼕
류병%공박옥%마숙매%류효동
CT扫描%低剂量电离辐射%健康效应%DNA损伤
CT掃描%低劑量電離輻射%健康效應%DNA損傷
CT소묘%저제량전리복사%건강효응%DNA손상
Computed tomography%Low dose vadiation%Health effects%DNA damage
目的 研究CT多次扫描对小鼠外周血淋巴细胞和骨髓细胞的影响,探索CT扫描对机体的损伤效应机制.方法 BALB/c小鼠60只,按随机数字表法,分为对照组、1、2、4、6和8次CT扫描组共6组,每组10只.对照组不扫描,扫描组用64排螺旋CT以骨盆模式对小鼠进行全身扫描,采用热释光技术检测小鼠局部吸收剂量.采用流式细胞术,在照后lh检测小鼠外周血淋巴细胞和骨髓细胞DNA损伤形成的γ-H2AX焦点,在照后24 h检测细胞凋亡、自噬、细胞周期和外周血CD4+、CD8+水平变化.结果 6组小鼠相应的辐射剂量分别约为0、63.09、124.14、174.48、232.99和504.72 mGy.扫描2次以上的小鼠外周血淋巴细胞和扫描4次以上的骨髓细胞中,y-H2AX均显著增加(P＜0.05),4次以上扫描使外周血淋巴细胞凋亡增加(P＜0.05),但使骨髓细胞凋亡降低(P＜0.05),体现出淋巴细胞更为敏感而骨髓细胞成分复杂且具有不同的辐射敏感性及反应时相性.CT扫描对外周血淋巴细胞自噬水平无影响,但单次扫描使骨髓细胞自噬增加(F=81.104,P＜0.05).扫描8次后骨髓细胞Go/G1期和G2/M百分率增加(x2 =11.29、28.57,P＜0.05).外周血CD4+、CD8+细胞亚群百分率在CT扫描后下降(P＜0.05),但CD4 +/CD8+比值未见明显变化.结论 CT多次扫描对造血系统和免疫系统产生了损伤效应,机体进而启动凋亡、自噬和细胞周期阻滞来维持基因组稳定性,而机体的免疫平衡未受影响.
目的 研究CT多次掃描對小鼠外週血淋巴細胞和骨髓細胞的影響,探索CT掃描對機體的損傷效應機製.方法 BALB/c小鼠60隻,按隨機數字錶法,分為對照組、1、2、4、6和8次CT掃描組共6組,每組10隻.對照組不掃描,掃描組用64排螺鏇CT以骨盆模式對小鼠進行全身掃描,採用熱釋光技術檢測小鼠跼部吸收劑量.採用流式細胞術,在照後lh檢測小鼠外週血淋巴細胞和骨髓細胞DNA損傷形成的γ-H2AX焦點,在照後24 h檢測細胞凋亡、自噬、細胞週期和外週血CD4+、CD8+水平變化.結果 6組小鼠相應的輻射劑量分彆約為0、63.09、124.14、174.48、232.99和504.72 mGy.掃描2次以上的小鼠外週血淋巴細胞和掃描4次以上的骨髓細胞中,y-H2AX均顯著增加(P＜0.05),4次以上掃描使外週血淋巴細胞凋亡增加(P＜0.05),但使骨髓細胞凋亡降低(P＜0.05),體現齣淋巴細胞更為敏感而骨髓細胞成分複雜且具有不同的輻射敏感性及反應時相性.CT掃描對外週血淋巴細胞自噬水平無影響,但單次掃描使骨髓細胞自噬增加(F=81.104,P＜0.05).掃描8次後骨髓細胞Go/G1期和G2/M百分率增加(x2 =11.29、28.57,P＜0.05).外週血CD4+、CD8+細胞亞群百分率在CT掃描後下降(P＜0.05),但CD4 +/CD8+比值未見明顯變化.結論 CT多次掃描對造血繫統和免疫繫統產生瞭損傷效應,機體進而啟動凋亡、自噬和細胞週期阻滯來維持基因組穩定性,而機體的免疫平衡未受影響.
목적 연구CT다차소묘대소서외주혈림파세포화골수세포적영향,탐색CT소묘대궤체적손상효응궤제.방법 BALB/c소서60지,안수궤수자표법,분위대조조、1、2、4、6화8차CT소묘조공6조,매조10지.대조조불소묘,소묘조용64배라선CT이골분모식대소서진행전신소묘,채용열석광기술검측소서국부흡수제량.채용류식세포술,재조후lh검측소서외주혈림파세포화골수세포DNA손상형성적γ-H2AX초점,재조후24 h검측세포조망、자서、세포주기화외주혈CD4+、CD8+수평변화.결과 6조소서상응적복사제량분별약위0、63.09、124.14、174.48、232.99화504.72 mGy.소묘2차이상적소서외주혈림파세포화소묘4차이상적골수세포중,y-H2AX균현저증가(P＜0.05),4차이상소묘사외주혈림파세포조망증가(P＜0.05),단사골수세포조망강저(P＜0.05),체현출림파세포경위민감이골수세포성분복잡차구유불동적복사민감성급반응시상성.CT소묘대외주혈림파세포자서수평무영향,단단차소묘사골수세포자서증가(F=81.104,P＜0.05).소묘8차후골수세포Go/G1기화G2/M백분솔증가(x2 =11.29、28.57,P＜0.05).외주혈CD4+、CD8+세포아군백분솔재CT소묘후하강(P＜0.05),단CD4 +/CD8+비치미견명현변화.결론 CT다차소묘대조혈계통화면역계통산생료손상효응,궤체진이계동조망、자서화세포주기조체래유지기인조은정성,이궤체적면역평형미수영향.
Objective To investigate the effects of repeated computed tomography (CT) scan on hematological and immunological index in mice,and to explore the related mechanism.Methods A total of 60 BALB/c mice were randomly divided into six groups as control,once,twice,4,6 and 8 times of CT scans,and administered with whole-body scan by 64-slice spiral CT with the pelvis scan mode.Thermoluminescence dosimeter was used to detect the absorbed doses of CT scan,while DNA damage (γ-H2AX),apoptosis,autophagy,cell cycle and percentages of CD4/CD8 in peripheral lymphocytes and bone marrow cells were analyzed by flow cytometry.γ-H2AX was detected 1 h after the last CT scan,and the other indexes were detected 24 h after the last CT scan.Results γ-H2AX increased after more than twice CT scans in peripheral lymphocytes and after than 4 times of CT scan in bone marrow cells (P ＜ 0.05).Apoptosis increased in peripheral blood lymphocytes and decreased in bone marrow cells after more than 4 times of CT scan (P ＜ 0.05),suggesting that lymphocytes were more sensitive while different cell subpopulation in bone marrow showed different sensitivity and response phase.No obvious changes of autophagy level were observed in peripheral blood lymphocytes,while autophagy increased in bone marrow cells after single CT scan (F =81.10,P ＜ 0.05).8 times of CT scan significantly increased the percentages of cells at G0/G1 phase and G2/M phase(x2 =11.29,28.57,P ＜0.05).The percentage of CD4 + T,CD8 + T cells decreased after CT scan,but no effects on the ratio of CD4 +/CD8 +.Conclusions Repeated CT scans could induce injury effects on hematopoietic system and immune system,and then the apoptosis.Apoptosis,autophagy and cell cycle arrest might be initiated to maintain genome stability but there is no influence on immune balance.
