Induction of sister chromatid exchanges by styrene and its presumed metabolite styrene oxide in the presence of rat liver homogenate

Styrene and its metabolite styrene oxide were tested for their ability to induce sister chromatid exchanges (SCE) in CHO cells. Styrene oxide appeared to be a potent inducer of SCE. Styrene itself did not increase the number of SCE per metaphase, even in the presence of a metabolic activation system. The metabolic activation system decreased the SCE induction caused by styrene oxide. Induction of SCE by styrene in the presence of metabolic activation occurred when cyclohexene oxide was used as an inhibitor of the enzyme epoxide hydrase.