低剂量率裂变中子长期照射对大鼠外周血细胞的影响

Effects of Long-term,Low Dose Rate Fission Neutron Irradiation on the Peripheral Hematological Cells in Rats.

目的探讨低剂量率裂变中子长期照射对大鼠外周血细胞的影响。方法96只雄性大鼠均分成对照组和照射组，照射组每天用低剂量率裂变中子（252Cf，吸收剂量率为0．35mGy/h）照射20．5h，在照射的第14d，28d，42d，56d，70d及停止照射后35d各取8只大鼠，用血细胞计数仪测定大鼠外周血WBC、RBC、PLT、HGB、MCV及HCT。结果低剂量率中子累积照射可使大鼠外周血WBC明显下降，在累积剂量为0．3Gy和0．4Gy时白细胞数明显低于对照组（P〈0．05），在累积剂量0．5Gy及停止照射后35d，照射组的WBC非常显著低于对照组（P〈0．01）；低剂量率中子照射在累积剂量为0．2Gy时，RBC反而显著高于对照组（P〈0．01），同时红细胞压积（HCT）、血红蛋白（HGB）含量明显高于对照组，提示有血液浓缩现象。在其他剂量处，RBC则表现为下降趋势，但仅0．5Gy时RBC下降有统计差异（P〈0．05）；累积剂量为0．3Gy，0．4Gy及0．5Gy时，照射组HGB低于对照组（P〈0．05）；在停止照射后35d，照射组MCV明显高于对照组。仅发现在累积剂量为0．2Gy时，照射组PLT显著低于对照组（PLT）。结论累积剂量0～0．5Gy的低剂量率裂变中子照射对大鼠外周血RBC及PLT的影响相对较少，但可造成太鼠外周血WBC减少，且在停止照射后一段时间。白细胞总数仍难以恢复至正常水平。

Objective To evaluate the effects of long - term, low dose rate fission neutron irradiation on the peripheral hematological cells in rats. Methods 96 rats were randomly divided into the control group and the irradiation group with low dose rate fission neutron（ 2S2Cf,0. 35mGy/h） irradiation 20.5h every day. 8 rats of each group were killed at 14d,28d,42d, 56d,70d after irradiation and 35d after the irradiation, and their peripheral hematological cells were tested respectively. Resuits Compared with the control group,peripheral blood WBC was reduced significantly at the dose of 0. 3Gy and 0. 4Gy （P 〈 0. 05 ）, and was reduced remarkably at dose of 0. 5Gy（ P 〈 0.01 ） and 35d after stopping irradiation（ P 〈 0. 01 ）. At dose of 0. 2Gy, Peripheral blood RBC was abnormally higher comparing with the control group （P 〈 0. 01 ）, accompanying with higher HCT and HGB, which suggests condensed blood. At the other point, RBC tend to become lower, but only at dose O. 5Gy, and the difference is significant comparing with control group（P 〈0.05）. At dose of0. 3Gy, 0. 4Gy and 0. 5Gy, HCT were significantly lower comparing with control group. Comparing with control group, MCV was higher at 35d after stopping irradiation, and PLT was significantly lower in dose of 0. 2Gy. Conclusion Long - term irradiation with low dose rate fission neutron could significantly reduce peripheral blood WBC, with less effects on RBC and PLT. The reduced WBC could not recover at 35d after stopping irradiation.