Pandey B N, Mishra K P
Cellular and Free Radiation Biology Section, Radiation Biology Division, Bhabha Atomic Research Center, Mumbai, India.
J Biochem Mol Biol Biophys. 2002 Aug;6(4):267-72. doi: 10.1080/10258140290030870.
Ionizing radiation induced chemical/structural modification in liposomes and related changes in fluorescence intensity of incorporated 1,6-diphenyl 1,3,5-hexatriene (DPH) was investigated in egg lecithin unilamellar vesicles. A correlation was found to exist between the magnitude of malondialdehyde (MDA) formation and the fluorescence decay of incorporated DPH in liposomal membrane after gamma-radiation. The reduction of DPH fluorescence and formation of MDA following radiation were significantly affected when alpha-tocopherol was incorporated into the liposomes. The observed effects of alpha-tocopherol were found to be dependent on its concentration in the liposome. A marked difference in emission spectra of DPH was found on radiation of liposomes prepared with the probe compared with that obtained from the labeling of liposomes after radiation depending on the applied radiation dose. The observed reduction in quantum yield of DPH in radiated liposomes is interpreted in terms of its environmental changes to a greater polarity. These results suggest that DPH fluorescence may provide an index of radiation induced lipid peroxidation caused by free radical reaction in unilamellar lecithin liposomes.
在卵磷脂单层囊泡中研究了电离辐射诱导脂质体的化学/结构修饰以及包封的1,6 - 二苯基 - 1,3,5 - 己三烯（DPH）荧光强度的相关变化。发现γ辐射后脂质体膜中丙二醛（MDA）形成的量与包封的DPH荧光衰减之间存在相关性。当将α - 生育酚包封到脂质体中时，辐射后DPH荧光的降低和MDA的形成受到显著影响。观察到α - 生育酚的作用取决于其在脂质体中的浓度。根据所施加的辐射剂量，与辐射后用探针制备的脂质体相比，发现辐射后标记的脂质体的DPH发射光谱存在明显差异。辐射脂质体中观察到的DPH量子产率降低是根据其环境向更大极性的变化来解释的。这些结果表明，DPH荧光可能提供单层卵磷脂脂质体中由自由基反应引起的辐射诱导脂质过氧化的指标。
