RESUMO
The ability of the two organophosphorous insecticides "Dursban" and "Dichlorvos" to induce chromosomal abnormalities in mouse spermatocytes was investigated. Male swiss mice were intraperitoneally [i.p] injected with the doses 2, 4, 10 mg/kg[-1] body wt. of "Dursban" [dissolved in 0.1 DMSO] and 2.8, 3.5, 7 mg/kg[-1] body wt. of "Dichlorvos" and samples were taken 6. 24 and 48 hrs after the treatment. The percentage of chromosomal aberrations in diakinesis - metaphase I cells increased by increasing the concentration of both insecticides and reached its maximum 24 hrs following i.p. injection, its highest value was 19.3 +/- 1.61 [P < 0.01] and 16.5 +/- 0.63 [P < 0.01] 24 hrs after treatment with the highest dose of "Dursban" and "Dichlorvos" respectively. Compared with 25.5 +/- 0.97 [P < 0.01], 24 hrs after i.p. injection with mitomycin C" at 1 mg/kg[-1] body wt. The two insecticides induced abnormal chromosomal associations including univalents [autosomal and x-y univalents] and chains, as well as structural and numerical chromosome aberrations. Dursban and Dichlorvos induced a dose-dependent increase in the percentage of abnormal sperm heads. Its highest value was 15.48 +/- 0.73 [P < 0.01] and 10.8 +/- 0.89 [P < 0.01] after oral treatment with Dursban and Dichlorvos respectively, compared with 18.3 +/- 1.10 [P < 0.01] after treatment with "Mitomycin C"