ABSTRACT
Objective To study the effect of praziquantel on cells within sehistosomal ovum granuloma in the lung of mice.Methods Forty-eight mice were divided into 4 groups.Group A:first,the mice were injected with sehistosomal ova hypodermically in abdomen,and 10 days later,injected with schistosomal ova intravenously in the cauda;Group B:in addition to the injection of schistosomal ova as the same of Group A,the mice were administered with praziquantel[300 mg/(kg·d)]for 3 days,one day before the intravenous injection of the ova;Group C:in addition to the injection of schistosomal ova as the same of Group A,the mice were administered with praziquantel(75 mg/kg,B.i.d.) for 5 days weekly until the mice were sacrificed;Group D:the same as Group C but praziquantel was given to the mice from the 29th after the intravenous injection of the ova.Three mice of each group were sacrificed on the 7th,14th,28th,56th day after the intravenous injection of the ova and the lung tissues were fixed with formalin and the slices were HE stained.Twenty-five to thirty pieces of schistosomal ovum granuloma were examined and the neutrophilic granulocytes,eosinocytes,lymphocytes,fibroblasts and macrophages within the ovum granulomas were counted and the mean numbers of them of each group were calculated and compared.Results Compared with Group A,the mean numbers of neutrophilic granulocytes,eosinocytes and macrophages within the ovum granulomas were decreased significantly,and the extend of the increase of fibroblasts reduced significantly in the three groups administered with praziquantel,and especially in Group C.On the 56th day after the intravenous injection of the ova,the mean numbers of neutrophilic granulocytes,eosinocytes and macrophages decreased by 54.4%、87.0% and 23.1%,and the extend of the increase of fibroblasts reduce by 59.4%,respectively in Group C,compared with Group A.The numbers of lymphocytes did not change very much in 4 groups.Conclusion Praziquantel can restrain inflammatory cells and the hyperplasia of fibroblasts within schistosomal ovum granulomas.