许多致癌物、致突变物是以前致癌物、前致突变物形式存在,经体内代谢活化之后,才具有致癌、致突变作用。这些物质的代谢活化,有赖于哺乳动物微粒体内所含的各种酶的参与。目前,较多作者采用哺乳动物肝匀浆9,000g 上清液(即肝 S-9)对前致癌物进行体外代谢活化,研究化学致癌物的代谢过程、致癌原理和筛测环境 Many carcinogens, mutagens are former carcinogens, mutagens exist in the form of the body after metabolic activation, only carcinogenic and mutagenic effect. The metabolic activation of these substances depends on the involvement of various enzymes contained in the mammalian microsomal body. Currently, more authors use 9,000 g supernatant of mammalian liver homogenate (ie, liver S-9) to perform in vitro metabolic activation of pre-carcinogens and to study the metabolic processes, carcinogenesis and screening of carcinogens