Trypanosoma musculi in CBA mice: trypanocidal mechanism eliminating dividing forms.

Large, inocula of dividing form-enriched Trypanosoma musculi parasites, harvested from the peritoneal cavity of infected CBA mice, were given intravenously to mice at various times during the infection. Mice infected for 10 or 15 days (including T cell-deprived, infected mice) eliminated dividing parasites from the blood within a few min, whereas those at earlier stages (1 or 5 days) were less efficient. The initial control of T. musculi parasitaemia thus appears to be due to a trypanocidal mechanism rather than reproduction-inhibiting factor (ablastin).