Zucali J R
Department of Medicine, University of Florida, Gainesville 32610.
Leuk Lymphoma. 1994 Mar;13(1-2):27-32. doi: 10.3109/10428199409051648.
Current therapies for the treatment of malignancies are associated with significant limitations to the hematopoietic system since chemotherapy and radiation therapy do not discriminate between normal and malignant cells. Since bone marrow depression occurs at low to midlethal doses of irradiation, approaches to improving the therapeutic index of treatment must include measures to enhance the sensitivity of the tumor relative to normal hematopoietic tissue or, by reducing toxicity to normal hematopoietic tissues leaving tumor resistance unchanged. Radioprotective agents have been proposed to unravel the fundamental processes by which radiation itself damages hematopoietic tissue. In radiotherapy, the importance of these agents is derived from their potential use as selective protectors against radiation damage to normal hematopoietic tissue such that higher doses of radiation can be delivered to tumors to achieve a therapeutic advantage. A variety of agents have been and are being evaluated as possible protectants. These include aminothiols, synthetic polysaccharides, vitamins and cytokines. This review attempts to summarize the role both chemical and biological response modifiers play as hematopoietic radioprotectors. In addition, possible mechanisms of protection of hematopoietic stem cells from irradiation are discussed.
目前用于治疗恶性肿瘤的疗法对造血系统有显著限制，因为化疗和放疗无法区分正常细胞和恶性细胞。由于在低至中等致死剂量的辐射下会发生骨髓抑制，提高治疗指数的方法必须包括提高肿瘤相对于正常造血组织的敏感性的措施，或者通过降低对正常造血组织的毒性，同时保持肿瘤抗性不变。有人提出使用辐射防护剂来揭示辐射本身损害造血组织的基本过程。在放射治疗中，这些药物的重要性源于它们有可能作为选择性保护剂，防止正常造血组织受到辐射损伤，从而可以向肿瘤输送更高剂量的辐射以获得治疗优势。已经并正在评估多种药物作为可能的保护剂。这些包括氨基硫醇、合成多糖、维生素和细胞因子。本综述试图总结化学和生物反应调节剂作为造血辐射防护剂所起的作用。此外，还讨论了保护造血干细胞免受辐射的可能机制。
