Developmental Immunotoxicity of Atrazine in Rodents

  There is a substantial literature reporting that the developing immune system is more sensitive to toxic insult and that the measurable phenotype resulting from prenatal/neonatal exposure often differs from that seen in adult exposure models (reviewed in Holladay and Steven, and Smialowicz et al.). Atrazine is a common herbicidal contaminant of groundwater in agricultural areas in the USA. The potential immunotoxicity of atrazine has been extensively studied using adult‐exposure models; however, few studies have explored its immunotoxicity in a prenatal and/or lactational exposure model. Prenatal/lactational atrazine exposure affects the function of young adult rodent immune systems in both sex‐ and age‐dependant manners. In our studies, the humoural and cell‐mediated immune responses of offspring from atrazine‐exposed dams were assessed at two ages, 3 and 6 months of age to test the hypothesis that prenatal/lactational atrazine exposure would cause greater health complications as the mice aged. Male offspring showed a significant immunopotentiation at three moa that was not apparent at 6 months. Three‐month‐old female offspring showed no significant difference in immune response from controls. However, at 6 months, female litter mates showed a significant depression in their immune function. These results indicate a decreasing trend in immune capacity. Rooney et al. showed a significant depression of the immune function of young male rat exposure prenatally and lactationally to atrazine. These results demonstrate a sex‐ and age‐dependant effect of prenatal exposure to atrazine on the immune system of the adult offspring using two rodent strains.