分子氢对雄性生殖细胞的辐射防护效应与机制

With increasing utilisation of nuclear technologies in the energy production, medical and industrial applications, the likelihood of radiation exposure to occupational workers, patients and public have been increasingly highlighted for special attention. Spermatogenesis is especially sensitive to ionizing radiation，less than half men will loss their fertility after the whole boby irradiation. Recently, our department demonstrated that hydrogen pretreatment could protect cultured cells, intestine and heart in mice from ionizing radiation, and improve the 30-day-survival rate in irradiated mice. Testis was chosen to study the underlying radioprotective mechanism and role of hydrogen, because of the availability of assays in the mouse to detect radiation damage and because testis is one of the most sensitive targets in man that is damaged during irradiation. The studies of effect include early apoptosis of spermatogenic cells，viability of spermatogenic cells and endocrine function.The studies of mechanism include Fenton reaction，radiolysis of water，antioxidant status，oxidative damage and gene expression. The project will also open up a randomized, double - blind, placebo controlled trial which tested the radioprotective role of hydrogen on irradiated germ cells in men.

随着核技术广泛应用于能源、医学和工业领域，职业性工人、病人和公众暴露于电离辐射的危险性倍受关注。生精干细胞分化形变为精子的过程对电离辐射极为敏感，在接受过全身照射的男性人群中，仅有不足一半的人在未来还具有生育能力。近年我们首次发现分子氢具有良好的辐射防护作用，可以保护培养的细胞、小鼠造血系统、小肠和心脏，降低照射死亡率。由于精子发生对电离辐射的敏感性及对男性生育的重要性，本项目选择雄性小鼠为实验对象，在前期实验的基础上，系统研究分子氢对雄性生殖细胞的辐射防护效应，包括分子氢对照射后生殖细胞凋亡和活力影响，对睾丸内分泌功能的影响，以及辐射防护机制，包括分子氢的体内分布、与羟自由基的相互作用、对氧化还原系统的影响和基因表达调控的变化。本项目另将在部分患者中展开随机双盲安慰剂对照试验，初步论证分子氢对人类睾丸生殖细胞是否存在辐射防护作用。

雄性睾丸对电离辐射极为敏感。本项目以雄性小鼠为研究对象，证明了分子氢的辐射防护效应，包括分子氢显著抑制精原细胞和精母细胞的凋亡，分子氢有效保护精子发生；本项目阐明了分子氢是通过在活体内清除羟自由基来实现其辐射防护效应，但本项目未发现分子氢的基因/蛋白作用靶点；本项目以盆腔放疗患者为研究对象，进行了一项队列研究，目前的数据提示分子氢可能保护放疗患者的精子DNA，但并不改善他们的精液质量。