低剂量辐射减轻化疗对小鼠免疫功能的抑制作用

Low dose radiation reduces the immunosuppressive effect of cytotoxic agents on tumor-bearing mice

采用Lewis肺癌荷瘤C57BL／6，小鼠做为实验动物模型，研究低剂量X射线全身照射并用丝裂毒素C（MMC）全身化疗对荷瘤小鼠免疫功能的影响。结果显示：在Lewis肺癌接种10d给予3.0mg／kgMMC腹腔注射后12h，小鼠的胸腺细胞自发增殖力、脾细胞对ConA反应性、自然杀伤细胞（NK）、淋巴因子激活的杀伤细胞（LAK）功能及脾细胞白细胞介素Ⅱ（IL—2）产量均较单纯荷瘤组显著下降（P＜0．05～0．01）；在化疗前6h给予75mGyX射线全身照射，上述免疫学指标均有显著提高（P＜0．05～0．01）。提示：大剂量化疗前预先给予低剂量X射线全身照射，可部分减轻化疗所致的免疫抑制。

In order to study the effect of whole body irradiation (WBI) with low dose X-rays incombination with mytomycin C (MMC) on the immune functions of tumor-bearing mice,we usedC57BL/6 mice implanted with Lewis lung carcinoma as an experimental animal model. The resultshowed that 12 hours after 3. 0 mg/kg MMC I. P. administration,the spontaneous incorporation of3H-TdR into thymocytes, the reaction of splenocytes to ConA, the splenic production of IL-2 aswell as the cytotoxic activities of natural killer cells (NK) and lymphokine activated killer cells(LAK) were markedly decreased. When WBI with 75 mGy X-rays was given 6 hours before MMCtreatment,the above immune parameters significantly increased, compared with those in mice withMMC treatment alone. The rasults implicated that WBI with low dose X-rays before chemotherapycould partly antagonize the immunosuppressive effect of MMC.