Mutagenic effects of the organophosphate insecticide temephos on mice bone marrow cells ; Ação mutagênica do inseticida organofosforado temefós em células de medula óssea de camundongos

The mutagenic effects of organophosphorate temephos on mice bone marrow cells was investigated through the micronucleus formation test. Doses of temephos (27.75; 55.5 e 111.0 mg/kg) were orally administered to males and females Swiss Webster mice. Cyclophosphamide (CPA, 25 mg/kg) per via i.p. and water (10 mL/kg) were administered in mice as positive and negative control groups, respectively. Mutagenic effects were evaluated from 24h to 72h after giving a single dose, and after nine doses of 111.0 mg/kg weekly administered. Ten thousand bone marrow cells per experimental group were analyzed. In the positive controls, the percentages of polychromatic erythrocytes micronucleus (PCEMN) at 24h after a single dose were 1.63% in male and 2.77% in female mice. No PCEMN was observed in the negative controls group. Gradually increasing temephos doses induced PCEMN in 2.61, 3.50, and 3.69% males and 1.02, 1.37, and 1.33% females, respectively. After 72h, CPA caused 0.05% of PCEMN in both males and females; and the temephos caused 0.92% in males and 0.18% in females. In mice administered with nine doses of CPA, PCEMN was detected in 0.15% males and 0.8% females, although PCEMN values were significantly higher in temephos receiving mice group. The mutagenic effects of temephos on both male and female mice were evidenced by chromosome alterations inducing micronucleus formation. ; Foram investigados os efeitos mutagênicos do organofosforado temefós através da observação da formação de micronúcleos em eritrócitos policromáticos (PCEMN) da medula óssea de camundongos. Em camundongos Swiss Webster de ambos os sexos, foram administradas diferentes doses de temefós (27,75; 55,5 e 111,0 mg/kg) por via bucal-gástrica e água destilada (10 mL/kg) no grupo controle negativo; e ciclofosfamida (CPA) (25 mg/kg) foi administrada pela via i.p. no grupo controle positivo. Foram analisadas dez mil células da medula óssea por grupo experimental. Os efeitos mutagênicos foram avaliados nos períodos de 24, 48 e 72h após ministrar a dose única e ...