Chromosomal aberrations induced by the insecticide endosulfan in sheep peripheral lymphocytes in vitro

The chromosomal aberration assay is the most common and sensitive method for detecting the biological damage induced by a great variety of mutagenic, carcinogenic and environmental agents. In this study an organochlorine insecticide, endosulfan, was investigated for its ability to induce chromosomal aberrations in vitro using sheep peripheral lymphocytes. Lymphocyte cultures from two donors were exposed to four different concentrations of insecticide (4 x 10-3, 4 x 10-4, 4x10-5 and 4x10-7 M) for 48 h. At the lowest concentration (4 x 10-7 M) the percentage of aberrant cells was not significantly different (4.5 % versus 1.5 % in DMSO control, p<0.05). Higher concentrations of insecticide (4 x 10-3, 4x 10-4 and 4x 10-5 M) resulted in significant increases of the chromosome aberration frequency (11 %; 11 % and 9 % versus 1.5 % in DMSO control, p<0.05). The mitotic index was significantly decreased at the concentrations of 4 x 10-3; 4 x 10-4 M (p< 0.01) as well as 4x 10-5 M (p<0.05). In this species the insecticide tested induced a mutagenic effect at the higher concentrations which should not be attainable under agricultural conditions.