低剂量辐射对放射性肠损伤小鼠肠上皮自由基的影响

目的观察低剂量辐射（LDR）对小鼠肠上皮自由基的影响,探讨低剂量辐射预处理在急性放射性肠损伤中的保护作用。方法根据照射剂量将40只小鼠分为三组,分别为：空白对照组（0 cGy）、单纯攻击照射组（800cGy）、低剂量联合攻击剂量照射组（7.5 cGy＋800 cGy）,联合组内又分为间隔6 h预照射组、间隔24 h预照射组、间隔48 h预照射组。攻击性照射后72 h,肠组织匀浆检测LDR预照射对超氧化物歧化酶（SOD）、丙二醛（MDA）含量。结果与单纯攻击照射组相比,联合照射组在8 Gy照射后72 h可提高照射后肠组织SOD活力、减少MDA含量,且24 h预照射组SOD及MDA变化与6 h预照射组和48 h预照射组比较有统计学差异（P〈0.05）。结论在一定时间范围内,低剂量辐射预处理可促使肠内SOD升高和MDA下降,可能对小鼠急性早期放射性肠损伤有一定的保护作用。

Effects of low dose radiation pretreatment on radiation injuried intestine free radicle

Objective To observe the effect of low dose radiation on juried intestine free radicle.Methods Experiment rats were divided into the three goups randomly according to does,group one as the blank control group（0 cGy） ： group two as simple irradiated group without exposing to preirradiation（800 cGy）;group three as irradiated group with exposing to preirradiation（7.5 cGy＋800 cGy）.The group three were also divided into the three groups randomly according to does irradiated with LDR pretreament,and the intervals were respectively 6 hours,24 houes,48 hours.72 hours after challenge dose,the activity of the superoxide dismutase（SOD） and thecontent of malondialdehyde（MDA） were detected.Results Compared with the simple irradiated group,the group with LDR pretreatment showed increasing of SOD and decreasing of MDA at the 24-hour after 8 Gy irradiation.In addition,there were differences among the 12-hour group,the 72-hour group and the 24-hour group.Conclusions LDR pretreatment can increase SOD and decrease MDA in some period.The suitable LDR pretreatment could play a protective role in the acute intestinradiation injury.