Tissue-mediated mutagenicity of vinylidene chloride in Salmonella typhimurium TA1535

Vinylidene chloride is weakly positive in the Salmonella typhimurium TA1535 test, mediated by kidney and liver post-mitochondrial supernatant (S-9 mix) from normal mice, but strongly positive with the S-9 mix from the induced animals. In the case of mediation by rat tissue, only liver S-9 mix from induced animals affords a significant positive response. These findings agree with the greater availability in treated mice than in rats of reactive vinylidene chloride metabolites, 1,1-dichloroethylene oxide and chloroacetyl chloride [5], and with the vinylidene carcinogeneicity found in mice but not in rats [9]. Exploratory tissue-mediated testing of vinylidene chloride involving liver S-9 mix from marmosets and man suggests a trend in the generation of alkylating metabolites and their reactions with bacterial DNA for these primates which resembles rats more than mice.