Transforming activity of ethylene dibromide in BALB/c 3T3 cells

Ethylene dibromide was capable of inducing in vitro transformation of BALB/c 3T3 cells either in the presence or in the absence of exogenous metabolic activation (S9-mix). This transforming effect was evidenced by the induction of a higher number of transformed foci as compared to the controls performed with untreated cells or solvent vehicle-treated cells. In the absence of exogenous activation, all assayed doses (ranging from 23.4 micrograms/ml to 187.9 micrograms/ml) exerted transforming activity. Number of foci obtained in EDB-treated plates antransformation frequency of the target cells were higher than those detected in the transformation test performed in the presence of S9-mix.