低剂量γ射线诱导丝裂霉素C损伤小鼠胸腺细胞的适应性反应

Adaptive Response of Murine Thymocytes Induced by Low Dose γ-rays before MMC Exposure

目的 :探讨低剂量辐射诱导小鼠拮抗丝裂霉素C(MitomycinC,MMC)损伤作用的机制。方法 :小鼠接受低剂量γ射线作用后6h ,再给予损伤剂量的MMC ,然后通过流式细胞术和 3H_TdR掺入法观察小鼠胸腺细胞周期和DNA含量的变化。结果 :50mGy和100mGy照射加MMC组小鼠胸腺细胞 3H_TdR自发掺入率、S期细胞百分率明显高于单纯MMC对照组 (P<0.01,P<0.05)。胸腺细胞G0/G1 期细胞百分率明显低于单纯MMC对照组 ,100mGy照射加MMC组小鼠胸腺细胞G2/M期细胞百分率明显低于单纯MMC对照组。结论 :低剂量γ射线对MMC损伤小鼠胸腺细胞自发掺入能力和细胞周期进程具有刺激作用。

Objective:To observe the mechanism against MMC damage induced by low dose γ-rays on thymocytes in mice.Methods: The cycle progression and DNA contents of thymocytes were detected with flow cytometry and 3H-TdR 6 h after low dose radiation in male Kunming mice.Results: Compared with the simple use of MMC, The rates of spontaneous proliferation of thymocytes and S phase cell percentage significantly increased at the dose of 50 and 100 mGy combined with MMC(P<0.01, P<0.05).The percentage of G0/G1 phase cells was significantly decreased in irradiated and MMC group compared with that in simple MMC group.The percentage of G2/M phase cells was significantly reduced at dose of 100 mGy on thymocytes in irradiated and MMC group compared with that in simple MMC group.Conclusions: Low dose γ-rays effectively stimulates the synthesis of DNA and accelerates cell cycle progression on thymocytes in mice.