小鼠腮腺分割小剂量放射损伤的模型研究

A Model Study of Fractional Low-Dose Radiation Injury of the Parotid Gland in Mice

目的模拟头颈部肿瘤直接照射,探讨小剂量分割照射对小鼠腮腺的放射损伤。方法随机将30只小鼠分为两组:放射组(25只)和对照组(5只)。放射组模拟头颈部肿瘤放射方式对小鼠头颈部进行局部照射,1次/d,2Gy/次,每周连续照射5d,休息2d,累计照射30Gy,而对照组仅模拟放射组,照射剂量为0Gy。照射后第8、15、22d分别对放射组和对照组进行腮腺唾液流量的测定。各时间点采集完唾液后处死小鼠,取腮腺组织,切片HE染色,镜下观察小鼠腮腺组织形态学改变及Western blot实验检测水通道蛋白1(AQP1)表达情况。结果第8d、15d唾液流量与两组无明显差异,而放射第22d对照组的唾液流量为(76.60±1.27)nL/30min,放射组为(31.32±1.48)nL/30min,两组比较有明显差异(P<0.05)。放射组腮腺组织腺泡数量变少、萎缩且腺泡形状不规则。在放射组中第22d的腮腺组织AQP1表达降低(P<0.05)。结论模拟头颈部肿瘤直接照射,分割小剂量的间接照射能引起小鼠腮腺损伤,为临床中放射治疗技术的改进提供了一定的理论基础。

Objective To simulate the direct irradiation of head and neck tumors,the radiation damage to the parotid glands of mice by low-dose fractional irradiation was investigated.Methods Thirty mice were randomly divided into two groups:radiation group(25)and control group(5).The mice in the radiation group were irradiated locally on the head and neck of the mice by simulating head and neck tumor radiation,1 time/d,2 Gy/time,continuously irradiated for 5 days a week,rested for 2 days,and the cumulative irradiation was 30 Gy,while the control group only had the simulated radiation group,irradiated the dose is 0 Gy.On the 8th,15th and 22nd days after irradiation,the salivary flow of the parotid gland was measured for the radiation group and the control group,respectively.After collecting saliva at each time point,the mice were sacrificed,and the parotid gland tissue was collected and sliced for HE staining.The histomorphological changes of mouse parotid glands were observed under microscope and the expression of aquaporin 1(AQP1)was detected by Western blot.Results On the 8th and 15th days,there was no significant difference in the salivary flow between the two groups.On the 22nd day of radiation,the salivary flow of the control group was(76.60±1.27)nL/30 min and that of the radiation group was(31.32±1.48)nL/30 min.There was a significant difference between the two groups(P<0.05).The number of acinus in the parotid gland tissue of the radiation group was reduced,atrophied and the shape of the acinus was irregular.In the radiation group,the expression of AQP1 in the parotid gland tissue decreased on the 22nd day(P<0.05).Conclusion Simulated direct irradiation of head and neck tumors,indirect irradiation with fractionated small doses can cause parotid gland damage in mice,which provides a certain theoretical basis for the improvement of clinical radiotherapy technology.