全脑常规照射开放血脑屏障动物模型的建立

目的 建立全脑常规照射开放血脑屏障（blood—brain barrier，BBB）的鼠动物模型。方法 100只SD大鼠随机分为5组，依次为假照射组、10、20、30和40Gy组，每组20只，^60Coγ射线全脑常规照射，2Gy，次，5次，周，每日观察大鼠饮食、自主活动、并记录照射区皮肤与毛发、体重及神经系统症状变化，照射后16h每组随机选取4例用镧示踪电镜化学技术观察大鼠BBB超微结构的变化。结果实验大鼠均未出现可评价的异常神经行为及体征；各组的饮食、自主活动、皮肤与毛发无可评价的异常改变；体重增加无统计学意义（P〉0．05）。透射电镜观察显示照射后随照射剂量的增加出现BBB功能的改变，且与照射剂量呈正相关。结论该模型能较好地模拟临床放射治疗过程，易于操作，成功率高，是全脑常规照射后从病理生理学及分子生物学等方面研究BBB功能变化规律的良好模型。

Establishment of rat model of opening blood-brain barrier with conventional whole-brain irradiation

Objective To establish a rat model of opening blood-brain barrier with conventional whole-brain irradiation. Methods According to different dosage of irradiation, a hundred Sprague-Dowley rats were randomly assigned into five groups, the control group (no irradiation), and four irradiated groups at 10 grays,20 grays, 30 grays and 40 grays. The rats were administered to conventional fraction irradiation (2 Gy/day and 5 days a week) with routine 60Co gamma-rays. The intake of feed and autonomic activities were observed every day. Changes in skin and hair in the irradiated field, body weight, and center nervous system symptoms and signs were examined and recorded every week during irradiation. The neurological status was ranked on a scale based on the Mickley's Scale. Ultrastructure changes of blood-brain barrier at 16 hours after the last irradiation were examined with electron microscope using lanthanum trace labeling. Results Neither abnormal nervous sign, nor change of feed intake, skin and hair was observed in all the rats. No statistically significant difference of body weight was observed among the five groups (P>0.05). The effect that radiation can directly damage the function and structure of blood-brain barrier was proportional to irradiation doses. Conclusion This rat model is a suitable for study on blood-brain barrier pathophysiology and molecular biology after conventional whole-brain irradiation. ;