多次床旁摄片对早产鼠肺组织的影响

Influence of multiple bedside radiation on the lung of preterm SD rats

目的探讨多次床旁X线摄片对早产鼠肺组织氧自由基的影响。方法取孕21dSD大鼠（因频繁运动出现早产）分娩的早产鼠为研究对象，按临床早产儿可能接受的x线次数分组进行照片，每天1次，同时设对照组，分别于第2、4、6、8、10次摄片后4h随机取实验组10只，对照组5～6只断头取肺组织，行形态学检查、脂质过氧化产物丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性的测定。结果连续10次（每天1次）摄片，对早产鼠体重、肺重以及肺的形态学无明显影响（P〉0．05）；MDA含量在第8次摄片后达到最高[（24．45±8．30）nmol／mg肺组织，SOD活性持续升高至本实验结束，最终达（16．26±3．84）nU／mg肺组织]，和对照组相比，6次以上摄片实验组肺MDA和SOD含量高于对照组，差异有统计学意义（P〈0．05）。结论连续摄片具有剂量累加效应，超过6次床旁X线摄片的电离辐射能使早产子鼠体内氧化和抗氧化系统处于亢奋状态。

Objective To investigate the effect of multiple bedside radiation on oxygen free radical in neonatal lung tissue. Methods SD rats, on the 21st day of pregnancy, were induced to preterm delivery by frequent movement. And the premature pups were randomly divided to experiment group, who received clinical X-ray once a day, and control group without. Four hours after receiving radiography for 2, 4, 6, 8 and 10 times, 10 rats from the experimental group and 5 to 6 rats from the control group were sacrificed. The morphological examination was performed, malondialdehyde （MDA） and the activity of superoxide dismutase （SOD） were detected in the lung tissue. Results The consecutive radiography did not affect the lung weight, body weight and lung morphology of premature rats. MDA peaked to （24.45 ± 8.30） nmol/mg after the 8th radiography, the activity of SOD increased to （16.26±3.84） nU/mg at the end of the experiment. Compared with the control group, more than six times radiography significantly increased MDA and SOD level （P〈0.05）. Conclusions Consecutive radiography may have dose cumulative effects on premature SD rats. More than six times bedside X-ray could stimulate the oxidation and antioxidant system of the body.