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 ≤ 0.001, ANOVA followed by Tukey test), respectively.

The effect of chronic lead acetate trihydrate intoxication in Wistar rats on experimental Ascaris suum infestation and immunity

SPF male Wistar rats were exposed for four months to lead acetate trihydrate present in drinking water (100 mg/l) and subsequently infested with 1000 ± 100 infective A. suum eggs. Metabolic activity of phagocytes and proliferative activity of T-lymphocytes were investigated on Day 4 and 8 after A. suum eggs infestation (Day 130 and 134 of lead acetate trihydrate exposition). The results demonstrated that treatment with lead acetate trihydrate led to increased susceptibility to infestation, manifested by increased average number of A. suum larvae in the lungs of exposed rats compared to unexposed ones. Moreover, migration of A. suum larvae on Day 8 was associated with significant increase in index of metabolic activity of phagocytes in unexposed rats in comparison with controls. In contrast, in rats exposed to the lead and infested by A. suum eggs a non-significant increase in the studied immunological parameters was recorded. Significant differences in immunological parameters were observed between unexposed, infested and infested and exposed groups of rats. In the unexposed group of animals Ascaris suum infestation caused a significant increase in the index of metabolic activity of phagocytes and stimulation index of lymphocytes in comparison with lead exposed rats.