STUDIES ON CHEMICAL BASIS OF CELLULAR RADIOSENSITIZATION BY 5-BROMOURACIL SUBSTITUTION IN DNA .2. PULSE- AND STEADYSTATE RADIOLYSIS OF BROMOURACIL-SUBSTITUTED AND UNSUBSTITUTED DNA

被引:81
作者
ZIMBRICK, JD
WARD, JF
MYERS, LS
机构
[1] Laboratory of Nuclear Medicine and Radiation Biology, UCLA School of Medicine, University of California, Los Angeles, CA, 90024
[2] Department of Radiology, UCLA School of Medicine, University of California, Los Angeles, CA, 90024
[3] Department of Radiation Biophysics, University of Kansas, Nuclear Reactor Center, Lawrence, Kansas, 66044
来源
INTERNATIONAL JOURNAL OF RADIATION BIOLOGY AND RELATED STUDIES IN PHYSICS CHEMISTRY AND MEDICINE | 1969年 / 16卷 / 06期
关键词
D O I
10.1080/09553006914551581
中图分类号
Q6 [生物物理学];
学科分类号
071011 ;
摘要
Pulse- and steady-state radiolysis studies show two major differences in the radiation chemistry of aqueous solutions of E. coli DNA (DNA) and bromouracil substituted DNA (BU-DNA): on exposure of N2-saturated solutions to low doses of radiation the absorbance of BU-DNA increases while that of DNA decreases; the free radicals formed by OH· attack on BU-DNA decay more rapidly than those on DNA. The differences are explained with the help of results from the accompanying paper by a mechanism involving conversion of the BU moiety of BU-DNA to a uracil (U) moiety by reaction of BU-DNA with organic free radicals. Uracil-5-yl radicals are formed which may abstract H· from neighbouring deoxyribose moieties to give uracil and a radical which may lead to a single-strand break. A hypothesis for BU radiosensitization, based on these and earlier results, account for (a) more DNA base damage and (b) more single-strand breaks in BU-DNA than in DNA; and (c) formation of U in BU-DNA. © 1969 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.
引用
收藏
页码:525 / &
相关论文
共 14 条