辐射对造血微环境损伤在放疗中的意义

本文观察了500～3000rad、局部照射后一年内骨髓中CFU-S数的变化动态,同时了解造血微环境支持造血的功能之演变过程。实验发现,500rad照射后局部骨髓中CFU-S含量明显减少,恢复不稳定,同时造血微环境支持造血的功能亦有相类似的波形起伏的损伤修复过程。1000rad局部照射的骨髓中CFU-S有更显著的降低,恢复缓慢而不稳定,造血微环境支持造血的功能早期明显受损,以后虽有修复但不能恢复到正常水平。2000rad以上的X线照射可导致局部骨髓长期再生不良,造血微环境亦见剧烈而持久的功能缺陷,这一结果表明:局部照射后,屏蔽区正常造血干细胞不能在照射部位骨髓中正常种植增殖,其原因与局部造血微环境的功能障碍密切相关。

THE INFLUENCE OF HEMOPOIETIC MICROENVIRONMENT DAMAGE RESULTED FROM IRRADIATION AND ITS EFFECT ON RADIOTHERAPY

The number of hematopoietic stem cells was studied in the marow of locally-irradiated mice for investigating the kinetics of hemopoiesis. Separate analyses were carried out at 3, 7, 15 days and 1, 2, 3,4, 6, 9, 12 months after X-ray local irradiation. It was shown that ;500 rad X-irradiation led to a significant reduction of the number of CFU-S in , local-marrow, and the recovery of hemopoietic function was unstable, . In the femurs of mice irradiated with 1000 rads, the complete recovery of CFU-S content did not occur until the 4th post-irradiatioit month, and then, a 2nd even 3rd reduction of CFU-S number could be observed. 2000 and 3000 -rad local irradiation led to long-term marrow hypop-lasia sustained at least for 1 year.The hemopoiesis-supporting function of microenvironment was investigated using double irradiation method, the results showed that it was impaired in the similar pattern.It seems reasonable to postulate that the radiationinduced damage of hematopoietic microenvironment might serve as a deteriorating factor for hemopoietic failure and a retarding factor for the recovery of hemopoiesisi after irradiatidn.