RESUMO
OBJECTIVE: To observe the impact of Toxoplasma gondii infection on the level of oxygen free radicals and antioxidant enzyme in serum and testes of mice. METHODS: 40 BALB/c male mice were randomly divided into four groups. Five mice from each group were injected intraperitoneally with 2.5 x 10(3) tachyzoites of T. gondii, the others received PBS. Mice were sacrificed on the 1st, 3rd, 5th, and 7th day after inoculation. Samples of serum and testes were collected to determine the content of oxygen free radicals and superoxide dismutase (SOD). RESULTS: The concentration of the oxygen free radicals (NO, *OH, O2-) in serum and testes of the mice increased along with the days of infection. The concentration of SOD reached a peak on the 3rd day after the injection and then decreased. Both of oxygen free radicals and SOD showed a statistical difference with the control (P < 0.01). CONCLUSION: Acute infection of T. gondii leads to n increase of oxygen free radicals and SOD in the serum and testes of mice.