Ogawa Kazuma, Aoki Miho, Fukuda Tadahisa, Kadono Sumi, Kiwada Tatsuto, Odani Akira
Graduate School of Medical Sciences, Kanazawa University.
Chem Pharm Bull (Tokyo). 2017;65(3):261-267. doi: 10.1248/cpb.c16-00792.
Radioactive nuclides leak into the surrounding environment after nuclear power plant disasters, such as the Chernobyl accident and the Fukushima Daiichi Nuclear Power Plant disaster. Cesium-137 (Cs) (t=30.1 year), a water-soluble radionuclide with a long physical half-life, contaminates aquatic ecosystems and food products. In humans, Cs concentrates in muscle tissue and has a long biological half-life, indicating it may be harmful. myo-Inositol-hexakisphosphate (IP6) is a compound found in grain, beans, and oil seeds. IP6 has the ability to form insoluble complexes with metals, including lanthanum (La) and zinc (Zn). We hypothesized that La-IP6 and Zn-IP6 may promote the elimination of Cs from the body through the adsorption of La-IP6 and Zn-IP6 to Cs in the gastrointestinal tract. Therefore, in this study, we evaluated the adsorptive capacity of La-IP6 and Zn-IP6 complexes with Cs in vitro and in vivo. La-IP6 and Zn-IP6 complexes were stable in acidic solution (pH 1.2) at 37°C. In vitro binding assays indicated that La-IP6 and Zn-IP6 complexes adsorbed Cs, with the adsorption capacity of Zn-IP6 to Cs greater than that of La-IP6. To evaluate the usefulness of La-IP6 and Zn-IP6 in vivo, La-IP6 or Zn-IP6 was administrated to mice after intravenous injection of Cs. However, the biodistribution of Cs in the La-IP6 treated group and the Zn-IP6 treated group was nearly identical to the non-treated control group, indicating that La-IP6 and Zn-IP6 were not effective at promoting the elimination of Cs in vivo.
核电站灾难（如切尔诺贝利事故和福岛第一核电站灾难）发生后，放射性核素会泄漏到周围环境中。铯-137（Cs）（半衰期t = 30.1年）是一种具有较长物理半衰期的水溶性放射性核素，会污染水生生态系统和食品。在人体中，Cs会在肌肉组织中蓄积，且具有较长的生物半衰期，表明其可能有害。肌醇六磷酸（IP6）是一种存在于谷物、豆类和油籽中的化合物。IP6能够与包括镧（La）和锌（Zn）在内的金属形成不溶性络合物。我们推测，镧-IP6和锌-IP6可能通过在胃肠道中使镧-IP6和锌-IP6吸附Cs，从而促进Cs从体内排出。因此，在本研究中，我们评估了镧-IP6和锌-IP6络合物在体外和体内对Cs的吸附能力。镧-IP6和锌-IP6络合物在37°C的酸性溶液（pH 1.2）中稳定。体外结合试验表明，镧-IP6和锌-IP6络合物能吸附Cs，锌-IP6对Cs的吸附能力大于镧-IP6。为了评估镧-IP6和锌-IP6在体内的效用，在给小鼠静脉注射Cs后给予镧-IP6或锌-IP6。然而，镧-IP6处理组和锌-IP6处理组中Cs的生物分布与未处理的对照组几乎相同，这表明镧-IP6和锌-IP6在促进体内Cs排出方面无效。
