CAJ | 학술논문

目的观察植入不同活度放射性125Ⅰ粒子近距离照射后,大鼠后肢行为学和背根神经节(DRG)放射损伤的超微结构变化.方法 SD大鼠36只,采用随机数字表法随机分为3组:空白组(钛质空壳作为对照)和低、高活度放射性125Ⅰ粒子组.低、高活度组分别于L4～5、L5～6椎间孔植入1粒放射活度为14.8和29.6 MBq 125I粒子.3组分别于粒子植入术前24 h、术后48、168、336、720和1440 h,用vonFrey hair测量手术前后大鼠后肢50％的机械刺激撤足阈值(PWT),运用联合行为评分(CBS)对大鼠的后肢运动情况进行评估,于术后336和1440 h,每组取2只大鼠L5的DRG经电镜观察超微病理学变化.结果与术前进行比较,高活度组术后1440 h后肢50％的机械刺激撤足阈值明显升高(t=2.972,P＜0.05),CBS评分差异无统计学意义;低活度组术后336 h时DRG内大部分为正常形态的节细胞,少量异常细胞.低活度组术后1440 h和高活度组术后336 h背根神经节细胞核膜有皱褶,核仁边集,线粒体普遍肿胀,空泡变明显,溶酶体增多,部分内质网肿胀.高活度组术后1440 h时大量节细胞出现核膜皱缩,部分模糊,大部分空泡变,溶酶体明显增多,内质网肿胀扩张等细胞坏死表现.神经纤维的髓鞘皱缩,线粒体少,空泡样变化明显.未见细胞核固缩、凋亡小体等细胞凋亡迹象.结论放射性125Ⅰ粒子近距离照射可引起大鼠背根神经节超微结构损伤,引起后肢痛阈升高,对后肢运动无影响.
목적 관찰식입불동활도방사성125Ⅰ입자근거리조사후,대서후지행위학화배근신경절(DRG)방사손상적초미결구변화.방법 SD대서36지,채용수궤수자표법수궤분위3조:공백조(태질공각작위대조)화저、고활도방사성125Ⅰ입자조.저、고활도조분별우L4～5、L5～6추간공식입1립방사활도위14.8화29.6 MBq 125I입자.3조분별우입자식입술전24 h、술후48、168、336、720화1440 h,용vonFrey hair측량수술전후대서후지50％적궤계자격철족역치(PWT),운용연합행위평분(CBS)대대서적후지운동정황진행평고,우술후336화1440 h,매조취2지대서L5적DRG경전경관찰초미병이학변화.결과 여술전진행비교,고활도조술후1440 h후지50％적궤계자격철족역치명현승고(t=2.972,P＜0.05),CBS평분차이무통계학의의;저활도조술후336 h시DRG내대부분위정상형태적절세포,소량이상세포.저활도조술후1440 h화고활도조술후336 h배근신경절세포핵막유추습,핵인변집,선립체보편종창,공포변명현,용매체증다,부분내질망종창.고활도조술후1440 h시대량절세포출현핵막추축,부분모호,대부분공포변,용매체명현증다,내질망종창확장등세포배사표현.신경섬유적수초추축,선립체소,공포양변화명현.미견세포핵고축、조망소체등세포조망적상.결론 방사성125Ⅰ입자근거리조사가인기대서배근신경절초미결구손상,인기후지통역승고,대후지운동무영향.
Objective To observe the changes of the ultrastructure of dorsal root ganglion (DRG) and the behaviors of hind limb after implantation of radioactive 125Ⅰ seeds around the DRG in rats.Methods 36 adult male Sprague-Dawley rats were randomly divided into three groups with different radioactivity 125Ⅰ seeds implanted around DRG,named control group (no irradiation,n =12),low radioactivity group (14.8 MBq,n =12) and high radioactivity group (29.6 MBq,n =12).The paw withdrawal threshold and combined behavior score were observed 24 h prior to seed implantation and at 48,168,336,720 and 1440 h after the treatment.Two rats were killed at 336 h and 1440 h to observe the ultrastructure of L5 DRG.Results Compared to the control without operation,PWT of the high radioactivity group were significantly higher than that of other groups (t =2.972,P ＜ 0.05).The in most of DRG low radioactivity group at 336 h were normal with a few abnormal cells.The DRG at 1440 h in low radioactivity group and in at 336 h high radioactivity group showed nuclear membrane buckling,nucleolus-set,mitochondrial swelling,lysosome increase,endoplasmic reticulum dilation and vacuolization.At 1440 h in the high radioactivity group,most of nuclear membrane invaginated,part of nuclear membrane obscured and mitochondrial swelled,but nuclear pyknosis and apoptotic body were not observed.Conclusions DRG can be injured after implantation of radioactive 125Ⅰ around DRG,and the threshold of mechanical pain would be elevated after implanting radioactive 125Ⅰ seeds.