Fascioliasis: similarities of the anemia in rats to that produced by infused proline.

Fasciola hepatica releases large amounts of proline into the bile of its host. Significant increases in the levels of other amino acids in the bile also occur. The present investigation examines whether proline and these other amino acids may play a role in inducing the anemia that frequently accompanies fascioliasis. In experiments, rats were infused intra-abdominally for 2 weeks with 1 of 3 solutions: 20.0 mM proline in saline, a mixture of 8 amino acids (excluding proline) each at 2.0 mM in saline, or saline only. At the end of the experiments 2 cc of blood was removed from each rat, via cardiac puncture. The heparinized blood was used to count erythrocytes and reticulocytes, and to measure hematocrit and mean corpuscular volume (MCV). Analysis of variance disclosed highly significant differences in erythrocyte counts, MCV, and reticulocyte counts among the 5 groups. A Student-Newman-Keuls test indicated that the Proline and Infected groups were not different from each other (except for MCV, where proline's effect was more severe) and that both groups differed significantly from the Amino Acid group, the Saline group, and the Control group. Hence, it appears that infused proline can cause an anemia similar to that induced by Fasciola.