Studies in arginine metabolism by schistosomes Arginine depletion in mammals and snails infected with S. mansoni or S. hematobium

Abstract

1. 1. Schistosoma mansoni and S. hematobium infections appear to exert a deleterious effect on arginine levels in the sera of some mammalian host and in hemolymph and protein hydrolyzates of some snail vectors. 2. 2. In several lots of heavily infected mice, serum arginine levels were shown to approach zero. The depression of arginine was related to the severity of exposure to cercariae and to the duration of parasitism. Considerable increases in concentration of proline, alanine, ornithine and ammonia accompany the loss in arginine. 3. 3. Surveys of limited numbers of infected Macaca and Cercopithecus monkeys, as well as Tanzanian baboons, have not demonstrated a striking relationship between parasite burden and changes in amino acids concentration. 4. 4. The predilection for certain amino acids may be dictated by the adaptation from invertebrate to vertebrate host which this parasite is forced to accomplish.