Effect of atrazine on immunocompetence of red-eared slider turtle(Trachemys scripta)

The impact of agrichemicals on aquatic vertebrate species has been a matter of increasing concern to researchers and environmentalist. The present study aimed to evaluate the effect of atrazine (ATZ), a worldwide used herbicide, on some immune parameters of red-eared slider (Trachemys scripta). Twenty-four turtles (2 years old) were randomly distributed in four groups. Three groups were intraperitoneally injected once with one of three different doses of atrazine (0.01, 0.1 or 1.0 ng/g body mass), while one was maintained as control (saline injected). Blood samples were taken 1- and 2-week post-treatment. A positive correlation was found between atrazine (high dose) concentration and immunosuppressive effects as evidenced by lowered serum complement and lysozyme activities, reduced leucocyte number as well as their phagocytic activity and increased heterophil/lymphocyte ratio. These data demonstrate that turtles with elevated atrazine exposure exhibit immunomodulation.