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

ABSTRACT

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.