中文摘要：

目的观察SD大鼠心脏放射损伤时血清内皮素1（ET-1）和心肌肌钙蛋白Ⅰ（cTn-Ⅰ）表达水平的变化,以及将ET-1和cTnⅠ作为放射性心肌损伤诊断指标的可行性。方法采用随机数字表法,将健康雌性SD大鼠30只分为对照组和照射组。照射组大鼠采用直线加速器心前区照射,单次剂量25 Gy。照射后第5、15、30、60天经下腔静脉取血5 ml,离心后取血清,采用ELISA试剂盒,分别测定血清ET-1和cTnⅠ含量。结果照射组大鼠血清ET-1含量均高于对照组,但只有在照射第5天和第15天时与对照组的差异有统计学意义（分别P〈0.01和0.05）。cTnⅠ的含量在照射后30 d内均高于对照组,而后下降,但只有照射后第15天（P〈0.05）和第30天（P〈0.01）时与对照组间的差异有统计学意义。结论大鼠心脏放射损伤的早期血清ET-1和cTnⅠ含量即明显升高,可将血清ET-1和cTnⅠ作为诊断早期放射性心肌损伤的敏感性与特异性指标。

英文摘要：

Objective To investigate the the effect of radiation-induced heart injury（RIHD） on cardiac endothelin-1（ET-1） and cardiac troponin Ⅰ（cTnⅠ） in SD rats,and the possibility regarding ET-1 and cTnI as biomarker of RIHD was also explored.Methods Healthy female SD rats were randomly divided into two groups： the control group（C） and irradiation group（R）.The rats in R group were irradiated with linear accelerator at a single dose of 25Gy.Five milliliters blood was collected from the inferior vena cava on the 5th,15th,30th,60th day after radiation.Blood was centrifuged and serum was collected.Content of ET-1 and cTnⅠ in blood serum were detected by ELISA kits.Results The content of ET-1 in the R group was always higher than that in the C group（P0.01） during the whole process,and the difference between two groups had statistical significance only on the 5th day（P0.01） and 15th day（P0.05） after radiation.However,the content of cTnⅠ in R group was higher than that in the C group withtin 30 days after radiation,then decreased,and only on the 15th day（P0.05） and the 30th day（P0.01） after radiation,there was statistical difference between two groups.Conclusion The content of ET-1 and cTnⅠ in blood serum increase obviously after receiving RIHD,so these two indicators can be used as markers to diagnose early RIHD sensitively and specifically.