Abstract: Objective: To detecet the effect of herbicide atrazine(ATR) on immunologic function of the rats, and to clarify the immunotoxicity of ATR.Methods: A total of 32 Wistar rats were randomly divided into control group, low, middle and high doses of ATR groups (n=8); the rats in various groups were given 0,5, 25, and 125 mg·kg^-1 ATR for 28 d, respectively. The body weights and spleen indexes of the rats in various groups were detected; HE staining was used to observe the morphology of spleen tissue of the rats in various groups;lymphocyte transformation assay was used to determine the lymphocyte transformation rates in spleen cells of the rats in various groups; the killing activities of NK cells in spleen cells of the rats in various groups were detected;flow cytometry was used to detect the percentages of CD3⁺ and CD8⁺ T cells in spleen cells of the rats in various groups; ELISA assay was used to detect the serum levels of interleukin-1 (IL-1) and interleukin-6(IL-6) of the rats in various groups.Results: Compared with control group, the body weights of the rats in different doses of ATR groups had no statistically significant differences(P>0.05).Compared with control group, the spleen indexes of the rats in low and middle doses of ATR groups had no statistically significant differences(P>0.05),and the spleen index of the rats in high dose of ATR group was decreased(P<0.05).The HE staining results showed that compared with control group, the morphology of spleen tissue of the rats in low dose of ATR group had no significant changes; the germinal centers of spleen tissue of the rats in middle dose of ATR group were slightly decreased; the morphology of spleen tissue of the rats in high dose of ATR group had obviously degenerative changes, which were characterized by disappearance of germinal centers, diminution of white pulp, and congestion of red pulp. The results of killing activity detection of NK cells showed that compared with control group, the killing activities of NK cells of the rats in different doses of ATR groups had no significant differences(P>0.05).The spleen lymphocyte transformation assay results showed that compared with control group, the lymphocyte transformation rates of spleen cells of the rats in low and middle doses of ATR groups had no significant differences(P>0.05);the lymphocyte transformation rate of spleen cells of the rats in high dose of ATR group was decreased(P<0.05).The flow cytometry results showed that compared with control group, the percentages of CD3⁺ and CD8⁺ T cells of the rats in low and middle doses of ATR groups had no significant differences(P>0.05),and the percentages of CD3⁺ and CD8⁺ T cells of the rats in high dose of ATR group were decreased(P<0.05).The cytokine detection results showed that compared with control group, the serum levels of IL-1 and IL-6 of the rats in low and middle doses of ATR groups had no signifiant differences(P>0.05),and the serum levels of IL-1 and IL-6 of the rats in high dose of ATR group were increased(P<0.05).Conclusion: High dose of ART can induce the obvious immunotoxicity.

Key words: atrazine, immune function, interleukin 1, interleukin 6, spleen