Induction of micronuclei in rat bone marrow after chronic exposure to lead acetate trihydrate

Lead increasingly contributes to pollution of the environment and may play a role in the development of adverse effects in the human and animal body. Data concerning its mutagenic, clastogenic, and carcinogenic properties have been conflicting. In this study, we evaluated the frequency of micronuclei in bone marrow erythrocytes of rats treated with lead acetate trihydrate. Outbred Wistar rats were exposed to a daily dose of 100 mg/L drinking water for 125 days. The mean value of the total number of micronuclei observed in polychromatic erythrocytes of female rats was significantly higher than that found in the control group (13.375 +/- 2.722 against 9.625 +/- 3.204 micronuclei/1000 cells; P = 0.024 in ANOVA). In exposed female animals, no significant reduction of the ratio of polychromatic to normochromatic erythrocytes was observed (0.990 +/- 0.228 against 1.208 +/- 0.195; P = 0.060 in ANOVA). The effects of lead acetate trihydrate in male rats are both cytotoxic and genotoxic because of a decrease in ratio of polychromatic to normochromatic erythrocytes (0.715 +/- 0.431 against 1.343 +/- 0.306; P = 0.023, ANOVA followed by Tukey test) and an increase in frequency of micronucleated polychromatic erythrocytes (24.167 +/- 7.859 against 4.0 +/- 4.528 micronuclei/1000 cells; P < or = 0.001, ANOVA followed by Tukey test), respectively.