Macrophage function during Trypanosoma musculi infection in mice.

Quantitative and functional changes in peritoneal macrophages from mice infected with Trypanosoma musculi were investigated. Increase in the number and size and in the protein content of peritoneal macrophages and the presence of parasites in the peritoneal activity were observed during the course of parasitemia. Induced releases of H2O2 by macrophages were increased during parasitemia, but H2O2 release returned to normal after infection. A correlation was also observed between parasitemia and 99mTc colloidal uptake by peritoneal macrophages. These changes in macrophage function may indicate an activation of these cells.