4.5 Gy γ射线照射后比格犬凝血机制的改变

Clotting mechanism in beagles irradiated by 4.5 Gy γ-rays

目的 比格犬4.5 Gy γ射线照射后,经综合对症和细胞因子2种治疗,观察其凝血机制的改变.方法 血小板体外聚集实验、血栓弹力图（TEG）描记分法、出凝血时间检测.结果 照后7 d照射对照组、综合对症组血小板聚集率明显降低,TEG凝固时间（K）值升高,而细胞因子治疗组则变化不明显.照射后14 d照射对照组TEG各项参数变化最为明显,表现为凝血反应时间（r）、凝固时间（k）、r＋k和血栓最大凝固时间（M）值大幅度升高,凝血时间、血栓最大凝固时间延迟,血栓最大弹力度（Ma）值大幅度下降,血栓最大弹力幅度减小.细胞因子治疗组各项参数均好于综合对症组.照射对照组照射后14 d凝血酶时间明显延长,综合对症和细胞因子组于照后2-3周凝血酶时间最长,两组间差异无统计学意义.照后42 d,血小板体外聚集实验综合对症组75%动物血小板聚集功能处于极低水平（正常值的20%以下）,而细胞因子对症组仅有33%动物血小板聚集功能处于极低水平.结论 细胞因子新组合治疗可明显改善急性放射病比格犬血小板聚集和凝血功能.

Objective To explore the clotting mechanism in beagles irradiated by 4.5 Gy γ-rays after treatment with supportive care,or supportive care and combined cytokines.Methods Sixteen beagles were divided into irradiation control group,Supportive care group and combined cytokines treatment group.Platelet aggregation test,thrombelagtography （TEG） and the time measurement were analyzed in vitro.Results In irradiation group and supportive care group,the platelet aggregation rates in beagles were decreased markedly and the k value of TEG was increased 7 d post-irradiation,while those indexes in combined cytokines treatment group changed little.At 14 d post-irradiation,each parameter of TEG in irradiated group changed obviously.The values of r,k,r＋k and M were elevated significantly,clotting time and the maximum coagulation time of thrombus delayed,the Ma value was decreased markedly,and the maximum elasticity amplitude of thrombus was diminished.All parameters in combined cytokines treatment group were better than those in supportive care group.The thrombin time was prolonged obviously in irradiated group 14 d post-irradiation,while the thrombin time was the longest at 2-3 weeks post irradiation in supportive care group and combined cytokines treatment group（P〉0.05）.Conclusions Cytokines could improve the platelet aggregation and the blood clotting functions of beagles suffering from acute radiation sickness.