Effect of 2-fluorohistidine upon leukocytopoiesis in mice.

Administrationof L-2-fluorohistidine to mice produces a dose and time dependent leukopenia, hypocellularity with reduction in hematopoiesis in the spleen and bone marrow, and depletion of lymphocytes in the spleen, lymph nodes and cortex of the thymus. The LD50 is 250 mg/kg at five days. The effect on hematopoetic tissue is nearly as great at non-leathal "therapeutic" doses. Effects on circulating erythrocyte and reticulocyte levels and the deposition of hemosiderin in the spleen are minimal. At non-leathal doses the effects of this amino acid analog appear to be completely reversible after 6 to 10 days.A description of the toxicity, histopathology and a discussion of the possible mechanisms of action are presented.