Department of Radiation Medicine, Radiation Research Laboratories, Divisions of Microbiology & Biochemistry, Loma Linda University and Medical Center, Loma Linda, California 92354, USA.
Int J Radiat Biol. 2011 Jan;87(1):8-23. doi: 10.3109/09553002.2010.518203. Epub 2010 Nov 10.
Particle radiations could significantly impact astronaut health during space missions. This study quantified the effects of iron ion radiation on lymphocytes in two strains of mice differing in susceptibility to radiation-induced acute myeloid leukemia (AML) and thymic lymphoma (TL): C57BL/6 (AML resistant, TL sensitive) and CBA/Ca (AML sensitive, TL resistant).
The animals (n = 60/strain) were irradiated with ⁵⁶Fe(26+) (1 GeV) to total doses of 0, 0.5, 2 and 3 Gray (Gy) at an average dose rate of 1 Gy/min and euthanised on days 4 and 30 thereafter; blood, spleen, and bone marrow were collected for flow cytometry analyses. Cells expressing the following molecules were quantified: Cluster of differentiation (CD) 4, CD8, CD25, CD34, CD71, B220 (isoform of CD45 on B cells), NK1.1 (marker on natural killer or NK cells, C57B mice), panNK (marker on NK cells, CBA mice), and Sca1 (stem cell antigen 1).
Exposure to radiation resulted in different distribution patterns in lymphocyte populations and leukocytes expressing activation and progenitor markers in the two mouse strains. Significant main effects were dependent upon strain, as well as radiation dose, body compartment, and time of assessment. Especially striking differences were noted on day 4 after 3 Gy irradiation, including in the CD4:CD8 ratio [blood, C57 (2.83 ± 0.25) vs. CBA (6.19 ± 0.24); spleen, C57 (2.29 ± 0.12) vs. CBA (4.98 ± 0.22)], %CD25(+) mononuclear cells in bone marrow [C57 (5.62 ± 1.19) vs. CBA (12.45 ± 0.93)] and %CD34(+)Sca1(+) cells in bone marrow [CD45¹° gate, C57 (2.72 ± 0.74) vs. CBA (21.44 ± 0.73)].
The results show that genetic background, as well as radiation dose and time post-exposure, had a profound impact on lymphocyte populations, as well as other leukocytes, after exposure to iron ion radiation.
在太空任务中，粒子辐射可能会对宇航员的健康产生重大影响。本研究通过比较两种对辐射诱导的急性髓性白血病（AML）和胸腺淋巴瘤（TL）敏感性不同的小鼠品系（AML 抗性、TL 敏感的 C57BL/6 和 AML 敏感、TL 抗性的 CBA/Ca），定量评估铁离子辐射对淋巴细胞的影响。
动物（n=60/品系）以 0.5、2 和 3Gy（平均剂量率为 1Gy/min）的总剂量接受 ⁵⁶Fe（26+）（1GeV）照射，并在照射后第 4 和 30 天处死；采集血液、脾脏和骨髓，进行流式细胞术分析。定量分析表达以下分子的细胞：分化群（CD）4、CD8、CD25、CD34、CD71、B 细胞上的 B220（CD45 同工型）、NK1.1（自然杀伤或 NK 细胞标志物，C57B 小鼠）、panNK（NK 细胞标志物，CBA 小鼠）和 Sca1（干细胞抗原 1）。
暴露于辐射会导致两种小鼠品系的淋巴细胞群和表达激活和祖细胞标志物的白细胞出现不同的分布模式。辐射剂量、机体部位和评估时间的品系依赖性以及主要效应均具有显著影响。在 3Gy 照射后第 4 天，差异尤为明显，包括血液中 CD4:CD8 比值[C57（2.83±0.25）比 CBA（6.19±0.24）；脾脏中 C57（2.29±0.12）比 CBA（4.98±0.22）]、骨髓中 CD25（+）单核细胞的百分比[C57（5.62±1.19）比 CBA（12.45±0.93）]和骨髓中 CD34（+）Sca1（+）细胞的百分比[CD45¹°门，C57（2.72±0.74）比 CBA（21.44±0.73）]。
结果表明，遗传背景以及辐射剂量和暴露后时间对铁离子辐射后淋巴细胞群以及其他白细胞有深远影响。
