Availability of Iron Sorbitol for Hemoglobin Formation

The availability of iron sorbitol for hemoglobin synthesis has been studied in six young, healthy male volunteers made anemic by repeated venesections. The rate of Hb production from iron sorbitol was compared to that after oral iron therapy and was found to be of the same order except for the first week of treatment, when iron sorbitol gave a slower response. This delay was thought to be due to processing of the iron sorbitol complex before iron could be delivered to the erythroid marrow. In another group of six male volunteers, made iron deficient by phlebotomy, iron stores were created by iron sorbitol of a size as encountered in normal men. The availability of these iron stores for Hb production was studied by means of quantitative phlebotomy. The amount of iron mobilized from the iron sorbitol stores averaged 94% of the calculated store of 727 mg. No significant residual iron deposits could be demonstrated after completed venesections. The urinary iron excretion after desferrioxamine (DF) in subjects treated with iron sorbitol was found to be significantly higher than in subjects with normal iron stores of corresponding size. It was suggested that this was due to localization of a fraction of iron sorbitol to tubular cells of the kidneys where DF reaches a high concentration.