一、遗传毒物的性质遗传毒物包括化学致癌物和化学诱变物,可以将其分成二类: (1) 前遗传毒物(前致癌物,前诱变物) 这类遗传毒物包括很多分子结构不同的化学物质,其本身并不具有遗传毒性,而是在敏感机体中经代谢转变成终遗传毒物。如果在原来对这些化合物得到阴性结果的生物学测试系统中加入适当的酶,就可能获得阳性结果。(2) 终遗传毒物这类化合物由于具有与关键靶细胞(critical cellular targets)相互作用的内在特性而诱 I. THE NATURE OF GENETIC TOXICITY Genotoxic agents, including chemical carcinogens and chemical mutagens, can be grouped into two categories: (1) Pre-genotoxic agents (procarcinogens, pre-mutagens) These genotoxic agents include many different molecular structures The chemical itself, which is not genotoxic, is transformed into a terminal genotoxic agent in a sensitive organism by metabolism. Positive results may be obtained by adding the appropriate enzymes to the biological testing system that originally gave negative results for these compounds. (2) Terminal Genotoxic Agents Such compounds are induced by the intrinsic properties of their interaction with critical cellular targets