Geyer J R, Taylor E M, Milstein J M, Shaw C M, Hubbard B A, Geraci J P, Thornquist M, Bleyer W A
Jennifer Sacco International Research Laboratories, Children's Hospital and Medical Center, Seattle, WA 98105.
Int J Radiat Oncol Biol Phys. 1988 Aug;15(2):373-5. doi: 10.1016/s0360-3016(98)90018-9.
To investigate the interactions between methotrexate (MTX) and irradiation of the central nervous system, adult rats were infused with MTX via the lateral cerebral ventricle either before, during, or following single fraction irradiation to the cervical spine. Single doses ranging from 1600 cGy to 3200 cGy were administered and the dose-response curve for forelimb paralysis was compared with that seen in irradiated animals which did not receive MTX. There was no effect on the dose-response curve when MTX was administered simultaneously with or following irradiation compared to radiation alone. When MTX was given prior to irradiation, however, the entire dose-response curve shifted in the direction of radioprotection by approximately 225 cGy. Histopathologic examinations were consistent with this observation, with animals pretreated with methotrexate demonstrating significantly less white matter necrosis than observed in untreated controls. Protection of normal CNS tissue from radionecrosis, and from the associated paralysis, may be achieved with preradiation methotrexate.
为研究甲氨蝶呤（MTX）与中枢神经系统照射之间的相互作用，成年大鼠在单次颈椎照射前、照射期间或照射后，通过侧脑室注入MTX。给予1600 cGy至3200 cGy的单剂量照射，并将前肢麻痹的剂量反应曲线与未接受MTX的照射动物的曲线进行比较。与单纯放疗相比，MTX在照射同时或照射后给予时，对剂量反应曲线没有影响。然而，当MTX在照射前给予时，整个剂量反应曲线向放射保护方向移动了约225 cGy。组织病理学检查与该观察结果一致，甲氨蝶呤预处理的动物白质坏死明显少于未处理的对照组。放疗前给予甲氨蝶呤可保护正常中枢神经系统组织免受放射性坏死及相关麻痹的影响。
