Effects of multiple doses of T-2 toxin on the erythroid response capacity of mice following an extensive experimental bleeding.

Total nucleated cellularity and total erythroid cell populations were measured in spleen and bone marrow of mice at different times after treatment with 3 daily doses of T-2 toxin (2.0 mg/kg). It was found that the initial depletion of hematopoietic cells produced by the toxin was rapidly reverted in spleen, giving way after 48 hr to a significant hypercellularity which after 10 days was 2.5 times the normal levels, but this effect was not observed in bone marrow, which slowly recovered normal cellularity after 5 days. The cytological analysis revealed that there was a highly significant shift in the ratio of erythroid to non-erythroid cells, since erythroid cell populations increased by about 8-fold in spleen and nearly 2-fold in bone marrow between 10 and 35 days after intoxication. In order to test the integrity of the hematopoietic reserve capacity, a hemorrhagic stress was produced in intoxicated animals at 10-50 days after toxin exposure. It was found that the erythroid response capacity was significantly higher in the intoxicated animals compared to anemic controls. The results suggest that the initial cytotoxic damage produced by T-2 toxin in the hematopoietic system is followed by a significant erythroid hypercellularity, which can confer an increased capacity for response to a hemorrhagic emergency.