The utilization of in vitro mutagenesis techniques to explain strain,age and sex related differences in dimethylnitrosamine tumor susceptibilities in mice

The carcinogen dimethylnitrosamine (DMNA) is known to exhibit a high degree of strain, organ, age, and sex related tumor specificity in mice. Using microbial mutagenesis assays coupled with mouse tissue microsomal enzyme activation systems, evidence has been obtained that demonstrated a close relationship between the level of in vitro DMNA activation to a mutagen and in vivo tumor susceptibility. DMNA activation by liver, lung, and kidney microsomes from several mouse strains was compared by measuring the rate of mutagenic metabolites formed during incubation of the carcinogen in mutation assays using Salmonella typhimurium G-46 as the indicator microorganism.