p53 protein expression in peripheral lymphocytes from atrazine chronically intoxicated rats

The p53 expression in peripheral lymphocytes of rats chronically exposed to atrazine was investigated. The experiment was performed in female Wistar rats. Atrazine was administrated in different doses (2.7 and 5.4 mg/kg body weight), each dose once a day, 5 days per week, for 6 and 12 months. The percentage of rats peripheral lymphocytes expressing p53 protein was evaluated by immunocytochemical technique, using a monoclonal antibody (clone PAb 122) against a common epitope, both fbr the wild type and the mutant p53 protein. The results indicate that in the atrazine long-term administration, the serum level of atrazine is associated with: (i) Significantly increased percentage of lymphocytes expressing p53 protein for all treated animals; (ii) different p53 intracellular compartmentalization (nucleus and cytoplasm), depending on dose and time of atrazine administration. The present study suggests that atrazine modifies the p53 expression, which could confirm the clastogenicity of this herbicide, and that the detection of the p53 protein may serve as a biomarker for the long-term exposure to atrazine. (C) 1997 Elsevier Science Ireland Ltd.