金属硫蛋白对胸腺嘧啶的辐射保护作用  

RADIOPROTECTIVE EFFECT OF METALLOTHIONEIN ON THYMINE

作　　者：方兴旺[1] 吴季兰[1] 魏根栓[1] 

机构地区：[1]北京大学技术物理系

出　　处：《辐射研究与辐射工艺学报》1994年第1期1-6,共6页Journal of Radiation Research and Radiation Processing

基　　金：国家自然科学基金

摘　　要：用竞争动力学方法测定了金属硫蛋白清除ＯＨ自由基的速率常数，研究了在Ｎ２Ｏ饱和的水溶液中金属硫蛋白对胸腺嘧啶的辐射保护作用。结果表明金属硫蛋白能有效地清除ＯＨ，对胸腺嘧啶有良好的保护作用。对胸腺嘧啶的氧饱和甲酸钠水溶液γ辐解产物分析表明，Ｏ２－和Ｈ２Ｏ２不会直接造成胸腺嘧啶的损伤。The reaction rate Of metallothionein (MT) with hydroxyl radicalwas. determined to be ca. 1012mol-1.L.s-1 by studying the kinetic competition OfMT With ferrocyanide for OH which was generated in situ by irradiation. Radioprotective effect of MT on thyinine was studied in N2O--saturated phbsphate buffer solutions at pH 7. 0.Both isoforms of rabbit MT can protect thymine against radiation damage effectively, and their effectiveness is in the order of ZnMT--1 >ZnMT--2> (Cd,Zn) MT--1 > (Cd, Zn)MT--2. However,the dose reducing factor wasless than expected. Which was possibly due to the secondary reactions of RS withthymine or T(OH) radicals With MT. Radiation effect on thymine in O,--saturated0. 1 mol'L-l HCOONa:Sblution wad also studied, and the results showed that O2and H2O2 didn't cause direct damage to thymine.

关 键 词：金属硫蛋白 胸腺嘧啶 放射保护作用 

分 类 号：Q691[生物学—生物物理学]