Prevention of Bone-Marrow Aplasia Induced by Aminopterin with Folacin and Folinic Acid

Abstract

Summary and Conclusions

1. The daily oral administration of 10 μg aminopterin to weanling rats induced a severe aplasia in the bone marrow within 5 days. 2. The simultaneous injection of 150 μg leucovorin completely prevented the aminopterin toxicity. 3. Simultaneous injection of folacin was also effective in preventing toxic effects of aminopterin. Folacin was about 1/50th as active as leucovorin. 4. Ascorbic acid and/or vit. B₁₂ did not influence the effect of folacin, i.e., no augmentation of submaximum amounts of folacin by either ascorbic acid and/or vit. B₁₂ was observed.