Résumé
Objective To explore the effect of phenol oxidase antigen on liver pathologic change in mice infected with Schistosoma japonicum. Methods 42d-aged adult worms were incubated in RPMI 1640 containing 0.05% sodium phenobarbital for 8 h. The worms were washed three times with PBS (pH 6.8) and homogenized with a Teflon pestle. The homogenate was then centrifuged at 3000 g for 20 min at 4 ℃. Supernatant fractions containing phenol oxidase (PO) were analyzed by means of polyacrylamide gel electrophoresis (PAGE). The rude antigen of PO was obtained by cutting the corresponding gel of PO activities. Three groups were set up to observe whether PO could induce protective immunity: experiment group, adjuvant control group and water control group. On day 42 post infection with (40?1) cercariae of Schistosoma japonicum, the mice were sacrificed to observe liver pathologic changes. Results The liver surface of PO immunized group was rather smooth and the liver color was slightly gray. A few pale nods were seen indistinctly but not clearly. Necrosis and inflammatory cell infiltration were not clear. There were many immature eggs without granuloma reaction. The mean diameter and area of the granuloma in the experiment group were less than those in the control group. There were significant differences among the 3 groups (P