Abstract: Forty Wistar rats were randomly divided into 4 groups with 10 in each group. Group A served as normal control. The other 3 groups were injected intraperitoneally with Echinococcus granulosus protoscoleces 5×104 each. Six months later, group D was injected intraperitoneally with antibody against IL-10 2.0 μg/time, twice a day for 2 d. Two days later, rats in groups C and D were injected intraperitoneally with cyst fluid 5 ml each to induce allergic reaction. 30 min later， all the rats were sacrificed to observe the infection status and obtain peripheral blood. The level of IL-10, IgE and histamine in the sera was detected by ELISA. The results showed that 5, 6 and 5 rats in groups B, C and D were infected successfully, respectively, with 2 deaths in group A. The rats in groups C and D appeared nasal itching, sneezing and declined activity. 30 min later, the symptoms in group C got improved, but not for group D. The levels of IL-10 and IgE in groups C and D increased significantly compared to group B（P<0.05）. The levels of IL-10 and IgE in group D were （142.61±43.58） pg/ml and （20.67±1.58） μg/ml, respectively, lower than those in group C（P<0.05）. The level of histamine was（17.69±3.90） ng/ml, higher than that in groups B and C（P<0.05）. There was no significant difference in histamine level between B and C（P>0.05）.

Key words: Echinococcus granulosus, IL-10, Allergy, Rat