摘要
目的研究γ射线心脏局部照射对大鼠心脏血流灌注及功能的影响,为放射性心脏损伤的防治提供实验依据。方法12只Wistar雌性大鼠随机分为未照射组、照射组,每组6只,照射组行60Coγ射线20Gy单剂量照射,每日观察大鼠饮食、行为活动等变化,定期记录大鼠体重变化。照射后120天用超声心肌造影检测大鼠心肌血流灌注变化。照射后180天分离大鼠心脏,采用Langendorff离体心脏灌流法测定左室收缩压(LVSP)和左室内压力变化速率(dp/dtmax、dp/dtmin),并取大鼠心脏进行病理检查,用HE染色观察心肌组织病理变化。结果照射后180天大鼠的饮食、行为、精神状态无可评价的异常变化,组间动物体重增加无明显差异。照射组大鼠心肌微循环灌注较未照射组明显减低。大鼠离体心脏功能检测示照射组大鼠LVSP、dp/dtmax、dp/dtmin均较未照射组明显减低。心肌组织HE染色显示照射组心肌细胞变性坏死、心肌纤维化。结论γ射线心脏局部照射可致心肌血流灌注降低,导致心脏功能下降。
Objective To investigate the pathophysiological changes in irradiation-induced heart injury in rats in order to provide preventive and therapeutic strategies for irradiation-induced heart disease （RIHD）. Methods Experiments were performed using female Wistar rats with body weight of approximately 220g. 12 female Wistar rats were randomly assigned to two groups （sham-irradiated group and irradiated group）. Heart of rats was locally irradiated with ^60Coγ-ray at a dosage of 20 Gy. During the post-radiation period, the intake of food and activities of the animals were observed daily and the body weight was recorded monthly. On the 120th day after irradiation, myocardial perfusion was tested using real time myocardial contrast echocardiography （RTMCE）. On the 180th day after irradiation, the hearts were isolated from the rats of the both groups, and they were perfused with a Langendorff apparatus. Hemodynamic measurements, including peak systolic LV pressure （LVSP）, maximal rate of LV pressure rise （LV dp/dtmax） and fall （LV dp/dtmin） were studled. Then the hearts were examined pathologically with HE staining. Results Animals irradiated with single dose of 20Gy locally were apparently in a good condition during the observation period of 180 days. No differences in food intake, physical activities and body weight were observed between irradiated and control animals. However, myocardial blood velocity （beta） of irradiated rats was significantly lower than that of sham irradiated group （P〈20. 05）. Cardiac dysfunction was found in the hearts isolated from the irradiated rats, and there was significant difference in LVSP, LV dp/dtmax, LV dp/dtmin （P〈20. 01） between sham-irradiated and irradiated group. HE staining of irradiated hearts showed myocardial degeneration and necrosis, accompanied by varying degrees of interstitial fibrosis and/or perivaseular fibrosis in the ventricle. Conclusion Local heart irradiation with γ-my may damage myocardial perfusion and induce cardiac dysfun
出处
《解放军医学杂志》
CAS
CSCD
北大核心
2007年第6期571-573,共3页
Medical Journal of Chinese People's Liberation Army
基金
国际原子能机构(IAEA)资助项目(13305/R1)
关键词
Γ射线
辐射损伤
心肌血流灌注
心室功能
gamma rays
radiation injuries
myocardial perfusion
ventricular function
