Calyculin A诱导早熟染色体与低剂量电离辐射剂量-效应关系

Dose-Effect Relationship between Premature Chromosome Induced by CalyculinA and Low-dose Ionizing Radiation

目的探讨CalyculinA诱导早熟染色体凝集技术作为低剂量电离辐射生物剂量计的可行性。方法取健康成年人的抗凝外周静脉血,用X射线分别以0、0.1、0.25、0.5、0.75和1.0Gy照射。照射后将血样接种于RP-MI1640培养基中,于37℃、5%CO2恒温培养箱内培养48h,当培养24h时加入秋水仙素,终止培养前2h加入Calyculi-nA诱导早熟凝集染色体,收获制片并用Giemsa染液染色,观察G1、G2/M-PCC细胞中总畸变率、断片率、双着丝粒体加着丝粒环率与辐射剂量的效应关系。结果用CalyculinA可成功诱导人外周血淋巴细胞产生PCC,且总畸变率、断片率、双着丝粒体加着丝粒环率随照射剂量的增加而增加,最佳拟合曲线为二次多项式模式。结论 CalyculinA诱导PCC技术可以作为一种方法来估算低剂量受照者的辐射剂量,但是需要更多的资料来完善。

Objective To explore the feasibility of CalyculinA induced premature chromosome condensation to be used as a biodosimetry of low - dose ionizing radiation. Methods Peripheral blood was drawn from healthy adults and Anticoagulated with Heparin. a set of tubes was irradiated by X -ray. The irradiation dose included 0, 0. 1,0.25,0.5,0.75,1.0 Gy. After irradiation, the whole blood was added to each RPMI1640 medium, All incubations were Cultured for up to 48b at 37℃ in an atmosphere of 5% CO2 in air. Colcemid was added 24hours after cultures start and Calyculin A was added for the last 2 hours to induce PCC. The chromosome spreads were prepared, stained with Giemsa and observed under a microscope. The dose -response relationship of the total aberration, fragment, dicentric ＋ centric ring（ dic ＋ r） in the irradiated lymphocytes was examined. Results The PCC was successfully induced in lymphocytes with Calyculin A. The yield of chromosome aberrations increased with the dose going up. An aquadratic polynomial dose response model was fitted. Conclusion Premature chromosome condensation induced by Calyculin A can be used as a technology to estimate the radiation dosage of low - dose ionizing radiation, but still need more data to improve.