血二胺氧化酶在放射性肠道损伤中的变化及意义

摘要

目的 探讨血二胺氧化酶(DAO)在放射性肠道损伤中的变化及意义.方法 将41只健康比格犬,按照随机数字表法分为11个不同剂量辐射组(8、10、12、14、16、18、20、22、24、26、30 Gy,每组3只)及正常对照组(8只).对辐射组动物采用单次X线剂量照射肠道,检测8、10、12、14、16 Gy辐射组照射后第1、3、5、7天,18、20、22 Gy辐射组照射后第1、3、5天,24、26、30 Gy辐射组照射后第1、2、3天血DAO水平;照射后第3天对肠黏膜进行活检,评估损伤程度,比较各组差异.结果 除20 Gy辐射组呈持续升高趋势外,余辐射组照射后血DAO水平均随时间延长呈先高后低的趋势,8、10、12、14、16 Gy辐射组于照射后第3或第5天,18、22、24、26、30 Gy辐射组于照射后第1或第2天即达峰值,且总体呈辐射剂量越大,峰值越高趋势.辐射致肠黏膜损伤程度呈剂量依赖性,8 ～ 30 Gy辐射组病理损伤总分依次为(3.0±0.0)、(4.3±0.6)、(5.7±0.6)、(6.7±0.6)、(8.7±0.6)、(9.3±1.6)、(10.7±0.6)、(10.7±0.6)、(11.3±0.6)、(11.7±0.6)、(11.7±0.6)分.肠黏膜病理损伤评分与辐射剂量呈正相关(r=0.971,P＜0.05).照射后第3天,8 Gy辐射组轻度黏膜改变;10～ 14 Gy辐射组部分黏膜损伤,腺体扩张,炎性细胞浸润,血管充血、出血;16 ～30 Gy辐射组弥漫性肠坏死、糜烂、剥脱.结论 血DAO水平能反映辐射诱导的肠黏膜屏障功能受损情况,可作为放射性肠道损伤早期诊断的参考指标.%Objective To explore change and significance of diamine oxidase (DAO) in plasma in radiation induced intestinal injury.Methods Totally 41 heatthy Beagle dogs were randomly divided into control group (8 dogs) and 11 radiation groups (8,10,12,14,16,18,20,22,24,26,30 Gy,n=3 each group) receiving single irradiation.The DAO levels in plasma in 8,10,12,14,16 Gy radiation group 1,3,5 and 7 days after irradiation,in 18,20,22 Gy radiation group 1,3,5 days after irradiation,in 24,26,30 Gy radiation group 1,2,3 days after irradiation were measured.The pathological changes of intestinal mucosa 3 days after irradiation were observed and the damage score was assessed.Results The serum DAO showed trend of high-low along with the time except for 20 Gy radiation group (rising trend);the DAO reached the peak 3 or 5 days after irradiation in 8,10,12,14 and 16 Gy radiation group,1 or 2 days after irradiation in 18,22,24,26,30 Gy radiation group.The radiation induced intestinal mucosal injury was dose-dependently aggravated;the pathological damage scores in 8-30 Gy radiation groups were (3.0 ± 0.0),(4.3 ± 0.6),(5.7 ± 0.6),(6.7 ±0.6),(8.7±0.6),(9.3±1.6),(10.7±0.6),(10.7±0.6),(11.3±0.6),(11.7±0.6),(11.7±0.6) scores,respectively;the pathological damage score was positively correlated with radiation dose (r =0.971,P ＜ 0.05).Three days after radiation,8 Gy radiation group presented mild mucosal changes;10-14 Gy radiation group presented partial mucosal changes,glands expansion,inflammatory cell infiltration,congestion of vessels,and hemorrhage;16-30 Gy radiation group presented diffuse intestinal necrosis,erosion and denudation.Conclusion The concentration of DAO in plasma can reflect the radioactive injury of intestinal mucosal barrier and can be used as an early index for diagnosis of intestinal injury after radiation.