Sister chromatid exchanges [sces] in mice exposed to benzene

ABSTRACT

The study aimed to evaluate the cytotoxic and cytogenetic effects of benzene exposure on mice. Swiss Webster and BDFI mice were subjected to intraperitoneal [ip] injections of benzene at the concentrations of 2.6, 3.2, 4.6, 12.8 and 25.6 m.mol/kg. The effect of increasing benzene concentrations on cell division and sister chromatied exchanges [SCEs] induction in bone marrow and alveolar macrophages of intact mice and regenerating liver cells of hepatectomized mice were studied. The results showed clear dose response relationships in all cell types. No significant differences in SCEs frequencies were observed either among the three cell types or between Swiss Webster and BDFI mice. The hepatectomized Swiss Webster mice showed higher frequencies of SCEs than the intact mice however, the difference was statistically significant only at the concentration of 25.6 m.mol/kg. no significant increase in SCEs frequencies and benzene exposure at the beginning of the first cell cycle. Exposure of the mice to benzene for 4 successive days at the concentrations of 3.2 and 6.4 m.mol/kg respectively did not show significant increase in SCEs frequencies than that induced following single benzene exposure at the same concentrations. The average percentage of the second division metaphases showed appreciable reduction only at the concentration of 25.6 m.mol/kg. Hepatectomy failed to alter the cytotoxicity of benzene as evidenced by lack of reduction of second division cells of the exposed mice relative to the controls