Abstract: 　Objective To determine the level of five trace elements(Fe 2+ ?Cu 2+ ?Zn 2+ ?Ca 2+ ?Mg 2+ )in the spleen and changes of T lymphocyte and its subtype variations in peripheral blood from the rats infected with Toxoplasma gondii . Methods Twenty rats were randomly and equally divided into two groups: control group and experiment group. Each rat in the experiment group received an ip injection of 2 ml normal saline containing 1.5×10 6 tachyzoites of T. gondii . On the 64th day after injection of T.gondii , the changes in T lymphocytes (TL) and their subgroups, the helper T lymphocytes (Th) and the suppressor T lymphocytes(Ts) in the peripheral blood of the rats with T.gondii were determined by the assay of the lymphocytes labeled with intercellular acid α naphthyl acetate esterase. All the rats were killed and the atomic absorption method were used for detecting the level of trace elements in the spleen tissue. Results The number of TL and Th in experiment group was significantly lower than that of control ( P <0.01, P <0.01). The ratio of Th/Ts showed a significant difference between the two groups. The level of Fe 2+ ?Cu 2+ in experiment group was significantly reduced ( P <0.01). The amount of Mg 2+ in infected rats was higher than that of the control( P <0.01). No statistical difference in the content of Zn 2+ ?Ca 2+ was found between the two groups. Conclusion T.gondii infection might cause the changes in the TL and Th in peripheral blood and the changes in trace elements in spleen of the rats.

Key words: Toxoplasma gondii, trace element, rat, acid α-naphthyl acetate esterase, lymphocyte