The effects of ethanol and anticonvulsants on erythroid delta-aminolaevulinic acid synthase.

The activity of delta-aminolaevulinic acid (ALA) synthase was measured in bone marrow from 13 control subjects, 12 chronic alcoholic patients and 9 patients on long term anticonvulsant therapy. The majority of patients in both groups had macrocytic red cells in the absence of megaloblastic changes in the marrow. There was a significant increase in ALA synthase activity in the alcoholic patients but no significant increase in enzyme activity in the patients on anticonvulsants and overall there was no correlation of activity with MCV. The macrocytosis associated with these drugs does not therefore appear to result from accelerated erythroid haem synthesis.