Assessment of the ability of endosulfan to induce micronuclei in vitro in cultured sheep lymphocytes

The organochlorine insecticide, endosulfan, was investigated for its abilit y to induce micronuclei in vitro in sheep peripheral lymphocytes. Lymphocyt es from two donors were exposed to four different concentrations of insecti cide (4 x 10(-3), 4 x 10(-4), 4 x 10(-5) and 4 x 10(-7) M) for 48 h. The lo west concentrations used (4 x 10(-5) and 4 x 10(-7) M) did not change signi ficantly the micronucleus frequency (24/1000 at both concentrations versus 23/1000 in the DMSO control, p < 0.05). Higher concentrations of insecticid e (4 x 10(-3) and 4 x 10(-4) M) caused a significant dose dependent increas e in the number of micronuclei (64/1000 and 50/1000, respectively, p < 0.05 ). Many of the treated cells also possessed multiple micronuclei. Endosulfa n thus has a weak genotoxic effect in sheep peripheral lymphocytes in vitro .