Comparison of potency of human carcinogens: vinyl chloride, chloromethylmethyl ether and bis(chloromethyl)ether.

The alpha-chloroether carcinogen chloromethylmethyl ether (CME) and its impurity bis(chloromethyl)ether (BCME) are direct-acting alkylating agents. Vinyl chloride (VC) is an indirect-acting carcinogen but its accepted carcinogenic intermediate, chloroethylene oxide, is also an alpha-chloroether. Both CME-BCME and VC have been in industrial use since about 1950.

Evidence for the covalent interaction of carbon tetrachloride with mouse liver chromatin DNA in vitro.

Whole chromatin was isolated from livers of 8-12 week-old male B6C3Fl hybrid mice and incubated with 14C-labelled carbon tetrachloride (14CCL4) in the presence of hepatic microsomes from the same animals and an NADPH-regenerating system. The experiments were carried out at various concentrations of 14CCl4 and incubation times. Under the conditions used, 14CCl4 metabolite(s) bind quantifiably to chromatin DNA (ch.

Distribution of carbon tetrachloride-metabolite(s) to DNase I-sensitive and -resistant chromatin.

The distribution of carbon tetrachloride (CCl4) metabolite(s) to DNase I-sensitive and -resistant regions of mouse hepatic chromatin was determined following incubation of whole chromatin with [14C]CCl4 in the presence of hepatic microsomes and an NADPH-regenerating system. At 2 h of incubation, [14C]CCl4 metabolite(s) bound essentially to the same extent to DNase I-sensitive and -resistant chromatin regions. Binding of [14C]CCl4 metabolite(s) to DNase I-resistant regions, however, increased significantly over the DNase I-sensitive regions when incubation was prolonged to 4 h.