A total of 45 injections of guinea-pig kidney extract positive for Forssman antigen (0.1 mg nitrogen per injection) was administered to mice 21 days before infection and until 65 days after infection by Puerto Rico strain Schistosoma mansoni cercariae. Infected mice were killed on days 70 to 76 after infection, and parasitemia was determined. Pigment content, measured by total-iron determination, noted in pooled liver samples and adult worm pairs, increased significantly (p, <0.001) in mice receiving kidney extracts, as compared with normal and experimental control animals. Infected mice receiving extract showed similar increases in the percentage of nonviable eggs. The injection of extract alone into normal mice produced no apparent effects. The results suggest that guinea-pig kidney extract positive for Forssman antigen alters the metabolism of S. mansoni adults in mice.
Present address: Tropical Disease Center, St. Clare's Hospital, 415 West 51st Street, New York, N. Y. 10019.