Yamaoka K, Edamatsu R, Itoh T, Mori A
Radiation Safety Group, Central Research Institute of Electric Power Industry, Tokyo.
Free Radic Biol Med. 1994 Apr;16(4):529-34. doi: 10.1016/0891-5849(94)90132-5.
We previously found that low-dose X-ray irradiation or radon (weak alpha-ray) inhalation increases SOD activities and reduces lipid peroxide levels in various organs of 7-week-old rats or rabbits. In this study, we examined how the changes of SOD activity, lipid peroxide level, and membrane fluidity of the cerebral cortex in aged male Wistar rats (65 and 91 weeks old) were affected by low-dose X-ray irradiation (100 cGy or under) compared with those in 7-week-old rats, to elucidate the mechanism of aging inhibition. The following results were obtained: Although radiation sensitivity was observed to decreases with age, low-dose irradiation changed the Mn-SOD activity, lipid peroxide level, and membrane protein fluidity parameter of the cerebral cortex in the age rats to be closer to those in the youth. These findings suggest that the increased SOD activity induced by low-dose irradiation enhances biomembrane functions, and that the decrease of lipid peroxide level enhances the membrane protein fluidity.
我们之前发现，低剂量X射线照射或吸入氡气（弱α射线）可提高7周龄大鼠或兔子各器官中的超氧化物歧化酶（SOD）活性，并降低脂质过氧化物水平。在本研究中，我们研究了与7周龄大鼠相比，低剂量X射线照射（100 cGy及以下）如何影响老年雄性Wistar大鼠（65周龄和91周龄）大脑皮质中SOD活性、脂质过氧化物水平和膜流动性的变化，以阐明衰老抑制机制。获得了以下结果：虽然观察到辐射敏感性随年龄增长而降低，但低剂量照射使老年大鼠大脑皮质中的锰超氧化物歧化酶（Mn-SOD）活性、脂质过氧化物水平和膜蛋白流动性参数更接近青年大鼠。这些发现表明，低剂量照射诱导的SOD活性增加增强了生物膜功能，脂质过氧化物水平的降低增强了膜蛋白流动性。
