Mahmoud Sherif S, El-Sakhawy Eman, Abdel-Fatah Eman S, Kelany Adel M, Rizk Rizk M
Biophysics and Laser Science Unit, Research Institute of Ophthalmology, P.O. Box: 90, Giza, Egypt.
Radiat Environ Biophys. 2011 Mar;50(1):189-98. doi: 10.1007/s00411-010-0333-x. Epub 2010 Sep 24.
It is believed that any dose of ionizing radiation may damage cells and that the mutated cells could develop into cancer cells. Additionally, results of research performed over the past century on the effects of low doses of ionizing radiation on biological organisms show beneficial health effects, called hormesis. Much less is known about the cellular response to low doses of ionizing radiation, such as those typical for medical diagnostic procedures, normal occupational exposures or cosmic-ray exposures at flight altitudes. Extrapolating from the effects observed at higher doses to predict changes in cells after low-dose exposure is problematic. We examined the biological effects of low doses (0.01-0.3 Gy) of γ-radiation on the membrane characteristics of erythrocytes of albino rats and carried out osmotic fragility tests and Fourier transform infrared spectroscopy (FTIR). Our results indicate that the lowest three doses in the investigated radiation range, i.e., 0.01, 0.025 and 0.05 Gy, resulted in positive effects on the erythrocyte membranes, while a dose of 0.1 Gy appeared to represent the limiting threshold dose of those positive effects. Doses higher than 0.1 Gy were associated with the denaturation of erythrocyte proteins.
人们认为，任何剂量的电离辐射都可能损害细胞，而且突变细胞可能发展成癌细胞。此外，过去一个世纪对低剂量电离辐射对生物机体影响的研究结果显示出有益的健康效应，即兴奋效应。对于低剂量电离辐射（如医学诊断程序、正常职业暴露或飞行高度的宇宙射线暴露中常见的剂量）的细胞反应，人们了解得要少得多。从高剂量观察到的效应推断低剂量暴露后细胞的变化是有问题的。我们研究了低剂量（0.01 - 0.3 Gy）γ辐射对白化大鼠红细胞膜特性的生物学效应，并进行了渗透脆性试验和傅里叶变换红外光谱（FTIR）分析。我们的结果表明，在所研究的辐射范围内，最低的三个剂量，即0.01、0.025和0.05 Gy，对红细胞膜产生了积极影响，而0.1 Gy的剂量似乎是这些积极效应的极限阈值剂量。高于0.1 Gy的剂量与红细胞蛋白质的变性有关。
