低氧对小鼠骨髓有核细胞微核形成的放射防护效应

RADIOPROTECTIVE EFFECT OF HYPOXIC IRRADIATION ON MICRONUCLEUS FORMATION OF THE NUCLEATED CELLS IN THE MICE BONE MARROW

氧不仅是放射增敏剂,同时亦可视为一种有应用价值的放射防护剂。在呼吸低氧分混合气造成机体暂时低氧状态条件下照射,可使肿瘤周围正常组织氧分压迅速下降,得到一定防护,从而允许给予较常规更高的肿瘤治疗剂量,以期提高治疗比。本文报告实验小鼠在呼吸10.5％低氧混合气条件下照射,以骨髓有核细胞微核形成率为指标所取得的放射防护效应。

Comprehensive investigations have suggested that attempts to improve the efficacy of tumor radiotherapy are directed towards the control of hypoxic cells. In many cases the use of enormous radical dose may be necessary which is sometimes limited by tolerance of the surrounding normal tissues. In the present experiment, using a transient systemic hypoxia induced by breathing a gas mixture with 10.5% oxygen, mice were irradiated. Taking the micronu-cleus cell frequency (MCF) of hematopoietic cells in the mice bone marrow as criterion of the radiation effect, a radioprotective factor (RPF) of 1.45 was obtained. Hypoxic inhalation during irradiation has demonstrated a positive radi'oprotective effect on the normal tissues in our experiment. There will be a possibility to permit the administration of an increased tumor dose in clinic trials.