Endosulfan: lack of cytogenetic effects in male rats.

Cytogenetic effects of endosulfan (Thiodan) a member of the chlorinated hydrocarbon insecticide was tested in male albino rats. The insecticide was administered orally to rats at 0, 11.00, 22.00, 36.60 and 55.00 mg/kg daily for 5 days. The highest doses were associated with clinical signs of insecticide poisoning and death. Cytogenetic analysis of bone marrow cells and spermatogenial cells did not reveal any significant effect of the insecticides on chromosomes. The ratio of mitotic index and frequency of chromatid break in the two cell types had no correlation with the doses tested and was not very different from those of the control group.