Repair of O6-methylguanine damage in normal human tissues.
Repair of O6-methylguanine damage in normal human tissues.
复制标题
修复O6-甲基鸟嘌呤对正常人体组织的损伤。
DOI：
10.1007/978-1-4613-0637-5_31
复制
发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Wani,AA
中科院分区：
文献类型：
--
作者：
D'Ambrosio,SM;Wani,G;Samuel,M;Gibson-D'Ambrosio,R;Wani,AA
Humans are exposed to a variety of natural and man-made environmental agents. It has been estimated by Hemminiki and Vainio (1984) that humans ingest approximately 1 μg dimethylnitrosamine (DMNA) per day. Lawley (1989) estimates that the fraction of DNA guanine methylated at the O6position by DMNA is about 3 × 10-9or 10 O6-methylguanine (MeGua) molecules per genome containing 1.2 × 1010DNA nucleotides. A study by Umbenhauer et al., (1985) directly measured the amounts of O6-MeGua in the DNA of a non-exposed population and one exposed to DMNA in their diet. The level of O6-MeGua in the tissue samples obtained from half of the non-exposed and the majority of exposed individuals assayed were below the detection limit (100 O6-MeGua in molecules per genome) of the assay. The remaining non-exposed individuals exhibited 116 to 176 molecules per genome, while the exposed population exhibited significantly higher values between 236 and 664 O6-MeGuae molecules per genome. Although it is very difficult to relate the actual daily ingestion of the DMNA with daily adduct formation, these and other (Poirier, 1984; Perera et al., 1987; Manchester et al., 1988) data demonstrate that human exposure to chemical agents can cause the formation of detectable levels of DNA damage. One characteristic of all of these studies is the large inter-individual variation in the levels of DNA adduct detected.
