血清内皮素-1作为早期放射性肺损伤标志物的探讨

目的:探讨内皮素-1(ET-1)作为一种早期放射性肺损伤诊断及病情变化的血清学标志物的可能性。方法:将190只雌性SD大鼠随机分为正常对照组(C组)和实验组,即:放射组(R组)、氟代他汀(Flu)干预组(Flu组)、维甲酸干预组(Ra组)及地塞米松(Dex)干预组(Dex组)。实验组大鼠麻醉固定后,用直线加速器全胸照射15Gy1次,剂量率为2Gy/min,距离为1m。从照射后次日开始,Flu组经胃灌服Flu(20mg·kg-1·d-1),Ra组灌服Ra(20mg·kg-1·d-1),Dex组灌服Dex(3.33mg·kg-1·d-1),C及R组均灌服等量的生理盐水。各组分别于照射后5、15、30、60d,将大鼠分批断头或经心内穿刺取血,分离血清;同时切取肺组织,用放射测定法(RIA)分别测定ET1,层黏连蛋白(LN)及透明质酸(HA)的水平;同时观察肺部的病理变化。结果:与C组相比较,R组大鼠血清ET-1的水平于照射后第5天开始升高(P<0.05),尔后随着放射性肺损伤的加重逐渐升高,于照射后60d检测达高峰。R组大鼠血清LN的水平于照射后30d开始升高,HA于照射后60d开始升高。R组大鼠血清ET-1水平的升高明显早于其他各组,且同放射性肺损伤的病理变化的程度相关。结论:血清ET-1可作为放射性肺损伤早期诊断及动态监测病情变化的一种标志物。

Exploration of serum endothelin-1 as a marker of early radiation lung injury

AIM: To explore the possibility of endothelin-1(ET-1) as a serological marker of early diagnosis and progression of radiation induced lung injury. METHODS: One hundred and ninety female rats were randomly divided into control group (group C) and experimental groups, namely, radiation group (group R), fluvastatin treatment group (group Flu), retinoic acid treatment group (group Ra) and dexemethasone treatment group (group Dex). The chests of rats in experimental groups were exposed to radiation by linear accelerator after anesthesia. The radiation dose for each rat was 15Gy, 2Gy per minute, and radiation distance was 1 meter. The next day after radiation, fluvastatin (20 mg. kg(-1). d(-1) ) was administered orally in group Flu, retinoic acid (20 mg. kg(-1). d(-1)) in group Ra and dexemethasone (3.33 mg. kg(-1). d(-1)) in group Dex. The rats in group C and group R were medicated with the equal volume of normal saline. On the 5th, 15th, 30th, and 60th day after radiation, five rats were randomly chosen from each group respectively. The sera were harvested by decapitation or cardiopuncture and at the same time, lung tissues were cut off. The levels of serum ET-1 and LN were detected by radioimmunological assay(RIA). The pathologic changes of lung tissue were observed under light microscope. RESULTS: Compared to the control group, serum ET-1 level began to increase on the 5th day after exposure to radiation and reached the peak on the 60th day in group R. The levels of laminin and hyaluronic acid began to rise on the 30th day and the 60th day respectively. The elevation of serum ET-1 level in group R was obviously earlier than that in other groups and correlated to extent of lung injury. CONCLUSION: The serum ET-1 can be used as a marker of early diagnosis and dynamic changes of radiation lung injury.