Benderitter M, Vincent-Genod L, Berroud A, Muller S, Donner M, Voisin P
Institut de Protection et de Sûreté Nucléaire, Département de Protection de la santé de l'Homme et de Dosimétrie, Fontenay-aux-Roses, France.
Int J Radiat Biol. 1999 Aug;75(8):1043-53. doi: 10.1080/095530099139818.
This study focused on radio-induced membrane alterations in order to assess some related parameters as potential biological indicators of ionizing radiation effects in cases of accidental overexposure.
Radio-induced membrane alterations were assessed after gamma-irradiation of human blood. Biophysical techniques based on fluorescent probe incorporation into isolated living lymphocytes and erythrocytes membranes were applied.
Using the technique of fluorescence polarization, the lipophilic phase of the membrane was shown to be more fluid whereas the lipid-protein interface of the membrane was shown to be more rigid after gamma-irradiation. Fluorescent anisotropy modifications showed dose-time effect relationships after radiation exposure. Ionizing radiation induced a decrease in steady-state anisotropy values but did not affect the probe's lifetime as assessed by fluorescence lifetime distribution technique. These data suggest that the anisotropy variations are representative of the local properties of the fluorescent probe's micro-environment. However, the distribution width showed a decrease pointing towards radiation-induced changes of membrane domain organization, probably due not only to membrane water penetration related to lipoperoxidation, but also to compositional changes and redistribution of membrane components. In contrast, the lack of radiation effect observed using the lateral diffusion index technique may be related to the integrated overview of the radio-induced modifications of the membrane provided by this technique, which pointed out radio-induced damage to the membrane in micro-domains.
These findings suggest the utility of structural membrane modification measurements as an early bio-indicator of ionizing radiation exposure.
本研究聚焦于辐射诱导的膜变化，以评估一些相关参数，作为意外过度暴露情况下电离辐射效应的潜在生物学指标。
在对人血进行γ射线照射后评估辐射诱导的膜变化。应用了基于将荧光探针掺入分离的活淋巴细胞和红细胞膜的生物物理技术。
使用荧光偏振技术，γ射线照射后膜的亲脂相显示出更高的流动性，而膜的脂 - 蛋白界面显示出更高的刚性。荧光各向异性修饰在辐射暴露后显示出剂量 - 时间效应关系。电离辐射导致稳态各向异性值降低，但通过荧光寿命分布技术评估，并未影响探针的寿命。这些数据表明各向异性变化代表了荧光探针微环境的局部特性。然而，分布宽度显示出降低，表明辐射诱导了膜结构域组织的变化，这可能不仅是由于与脂质过氧化相关的膜水渗透，还由于膜成分的变化和重新分布。相比之下，使用侧向扩散指数技术未观察到辐射效应可能与该技术提供的膜辐射诱导修饰的综合概述有关，该技术指出了微结构域中膜的辐射诱导损伤。
这些发现表明膜结构修饰测量作为电离辐射暴露早期生物指标的实用性。
