Selective vulnerability to radiation in the hippocampal dentate granule cells
Selective vulnerability to radiation in the hippocampal dentate granule cells
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DOI：
10.1016/s0090-3019(00)00214-7
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发表时间：
2000-05-01
影响因子：
--
通讯作者：
Asada, H
中科院分区：
文献类型：
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作者：
Nagai, R;Tsunoda, S;Asada, H
背景放射治疗是治疗生殖细胞瘤等对辐射高度敏感的脑肿瘤的有效方法。然而，最近的研究报告了儿童时期接受全脑照射的患者的智力障碍。方法100只4周龄ICR小鼠接受18GyX射线全身照射(0.45Gy.min)，每组10只，分别于照射后1、3、6、9、12、18、24、48、72 h断头取脑。对照组为10只未受辐射的小鼠。结果琼脂糖凝胶电泳法检测到DNA梯状条带，9h达高峰。即使在峰值，谱带强度也几乎是未受照射的正常胸腺的两倍。根据TUNEL分析，辐射诱导的细胞凋亡增加，在照射后9h达到高峰，但在照射后24h有所下降。结论我们发现海马齿状回颗粒细胞对辐射具有易感性。接受全脑照射的患者的智力障碍可能是由海马体损伤引起的。(C)2000年，爱思唯尔科学公司。
BACKGROUND Radiation therapy is an effective approach in the treatment of highly radiosensitive brain tumors such as germinomas. However, recent studies have reported intellectual disturbances in patients who underwent whole-brain irradiation as children. We detected apoptosis in the infantile murine cerebrum after systemic X-ray irradiation.METHODS Subjects were 100 ICR mice 4 weeks old, of which 90 were systemically exposed to 18 Gy X-rays (0.45 Gy/min); 10 each were decapitated and the cerebrums were removed 1, 3, 6, 9, 12, 18, 24, 48, and 72 hours after irradiation. Controls were 10 unirradiated mice. DNA fragmentation analysis was carried out by agarose gel electrophoresis, and morphological analysis was by the TUNEL method.RESULTS According to agarose gel electrophoresis, the cerebral DNA ladders were detected only over 6 to 24 hr, peaking in 9 hr. Even at the peak, band intensity was nearly double that of the unirradiated normal thymus. According to the TUNEL analysis, radiation-induced apoptosis increased, with a peak at 9 hours, but decreased 24 hours after irradiation. Apoptotic cells were always localized exclusively in the hippocampal dentate granule cells.CONCLUSIONS We found that vulnerability to radiation existed in the hippocampal dentate granule cells. Intellectual disturbances in patients who have undergone whole-brain irradiation may be caused by injury to the hippocampus. (C) 2000 by Elsevier Science Inc.