[Histochemical demonstration of tetrahydrofolate dehydrogenase in human bone marrow: apparent enzymatic induction after administration of folic acid antagonists].

Folate antagonists interfere to a varying extent with the histochemical demonstration of tetrahydrofolate dehydrogenase. Some aspects of this interaction are investigated in normal hemopoietic cells of patients following antitumor treatment with methotrexate. In this situation the histochemically detectable activity of tetrahydrofolate dehydrogenase exceeds the control levels (apparent enzymatic induction). A protection of the enzyme-metabolite complex from degradation and diffusion might be effective for the changes in reaction intensity.