Felkner I C, Hoffman K M, Wells B C
Mutat Res. 1979 Sep;68(1):31-40. doi: 10.1016/0165-1218(79)90075-2.
Mutagenic, DNA-damaging, and in vivo alteration of DNA have been demonstrated for 1,2-dimethylhydrazine (DMH), a potent inducer of adenocarcinomas of the large intestine and colon of rats. These activities are pH-dependent, with 6.5 giving optimum response. There was no requirement for metabolic activation with rat-liver S9 mix when the appropriate Bacillus subtilis mutant strains were used. The Rec- strains recA8 and mc-1 were greater than 300-fold more sensitive to the DNA-damaging activity of DMH than was their isogenic wild-type parent. The DNA isolated from DMH-treated mc-1 had altered spectroscopic characteristics, and gave a greatly reduced transformation efficiency. Treatment of B. subtilis strain TKJ6321 with DMH at pH 6.5 induced His+, Met+ mutations in substantial numbers at low concentrations of this chemical. The use of B. subtilis mutants in these studies has therefore made it possible to demonstrate mutagenic and DNA-damaging activity in bacteria for this potent carcinogenic chemical.
1,2 - 二甲基肼（DMH）是大鼠大肠和结肠癌的强效诱导剂，已证实其具有致突变性、DNA损伤性以及能在体内改变DNA。这些活性依赖于pH值，pH为6.5时反应最佳。当使用合适的枯草芽孢杆菌突变菌株时，无需大鼠肝脏S9混合液进行代谢活化。Rec - 菌株recA8和mc - 1对DMH的DNA损伤活性的敏感性比其同基因野生型亲本高300倍以上。从经DMH处理的mc - 1中分离出的DNA具有改变的光谱特征，且转化效率大幅降低。在pH为6.5的条件下，用DMH处理枯草芽孢杆菌菌株TKJ6321，在该化学物质低浓度时可诱导大量的His⁺、Met⁺突变。因此，在这些研究中使用枯草芽孢杆菌突变体能够证明这种强效致癌化学物质在细菌中具有致突变和DNA损伤活性。
