EFFECTS OF GAMMA-IRRADIATION ON CELLS AND THEIR CONSTITUENTS

伽马射线对细胞及其成分的影响

• 批准号: 3963248
• 负责人: P RIESZ
• 金额: --
• 依托单位: DIVISION OF CANCER TREATMENT
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3963248
• 关键词: DNA; cells; cytotoxicity; daunorubicin; doxorubicin; electron spin resonance spectroscopy; erythrocytes; food additives; free radicals; gamma radiation; ionizing radiation; light adverse effect; metalloporphyrins; mitomycin C; neoplasm /cancer photoradiation therapy; nonvisual photosensitivity; photolysis; phthalocyanin; porphyrins; radiobiology; radiopharmacology; radiosensitizer; tissue /cell culture; ultrasound; ultraviolet radiation

The effects of ionizing and ultraviolet radiation, of visible light, and of ultrasound on cells and their constituents are being studied. Certain tetrasulfonated phthalocyanines with maximum absorption in the 600-700 nm region and cyanine dyes (700-800 nm) are efficient photosensitizers for killing mammalian cells and appear to be promising candidates to replace hematoporphyrin derivative (Hpd) in photodynamic therapy (PDT) of tumors. The photochemical quantum yields for singlet oxygen formation from several tetrasulfonated phthalocyanines were measured. Those containing paramagnetic metals (copper, iron, vanadyl) do not generate singlet oxygen in contrast to those with diamagnetic metals (aluminum, zinc). The latter are efficient photosensitizers, while the former have no photobiological activity in the killing of mammalian cells. Similar results were found for the Type I photochemical ability as measured by one electron transfer to methyl viologen (paraquat) dication. The menadione sensitized photooxidation of nucleic acids and protein constituents was studied by ESR and spin trapping. The observed radical intermediates and stable products can be explained in terms of electron transfer from the substrate to the triplet state of menadione to form the radical cation of the substrate and the anion radical of menadione. A new method of introducing singlet oxygen as the only damaging species into aqueous solutions or into monolayers of mammalian cells was developed. This approach avoids complications due to Type I processes (hydrogen and/or electron-transfer) between the triplet state of the photosensitizer and the substrate and makes it possible to study the photobiological effects of Type II processes (singlet oxygen) alone.

电离辐射和紫外线辐射、可见光和 超声波对细胞及其成分的作用正在研究中。一定的 最大吸收波长在600-700 nm的四磺化酞菁 区域染料和菁染料(700-800 nm)是有效的光敏剂 杀死哺乳动物细胞，似乎是很有希望的替代品 血卟啉衍生物(HPD)在肿瘤光动力治疗中的应用 几种化合物形成单线态氧的光化学量子产率 测定了四磺酸基酞菁类化合物。那些包含 顺磁性金属(铜、铁、钒)不产生单线态氧 与含抗磁性金属(铝、锌)的材料形成对比。后者 是高效的光敏剂，而前者没有光生物 在杀死哺乳动物细胞方面的活动。类似的结果也被发现在 I型光化学能力由一个电子转移到 甲基紫精(百草枯)喷雾。甲苯二酮致敏 用电子自旋共振研究了核酸和蛋白质组分的光氧化 和自旋陷阱。观察到的自由基中间体和稳定产物 可以用电子从衬底转移到 形成底物的自由基阳离子的甲奈二酮的三重态和 甲萘二酮的阴离子基团。一种引入单线态氧的新方法 作为唯一有害的物种进入水溶液或进入单层 哺乳动物细胞被开发出来。这种方法避免了由于以下原因引起的复杂情况 三重态之间的第一类过程(氢和/或电子转移) 光敏剂和衬底的状态，并使其能够 第二类过程(单线态氧)的光生物效应研究 独自一人。