The enzymic formation of haem by human and rat tissues

Abstract
An enzyme system that incorporates iron into protoporphyrin has been demonstrated in human and rat liver, kidney and spleen and in human bone marrow. Studies on the intracellular components of human and rat liver showed that whereas iron incorporation occurred with all fractions, those containing the mitochondria were most active. Ascorbic acid and reduced glutathione potentiated the iron-incorporating-enzyme activity of all tissues. Dialysis of tissue homogenates led to loss of activity which was restored by addition of ascorbic acid or glutathione. The results confirm the important role which these substances play in the incorporation of iron.