Role of macrophages in host defense against hepatic amoebiasis in hamsters

The role of macrophages in hepatic amoebiasis in hamsters has been investigated by means of antimacrophage serum prepared in rabbits. Animals treated with normal rabbit serum or antimacrophage serum, as well as untreated controls, were inoculated intrahepatically with 10(5) axenic trophozoites of Entamoeba histolytica. In hamsters treated with antimacrophage serum before intrahepatic inoculation of amoebae, the mean weight of the metastatic foci was significantly greater than in normal rabbit serum-treated or untreated controls. Treatment of hamsters with antimacrophage serum both before and after administration of amoebae not only increased significantly the size of the abscess in the liver but also allowed dissemination of metastatic foci to other organs.