The Action of Copper in Iron Metabolism*

The importance of copper as a supplement to iron for hemoglobin regeneration in anemic rats was first demonstrated 4 years ago by Hart, Steenbock, Waddell, and Elvehjem (1). This work showed definitely that in the presence of copper, soluble inorganic iron salts can be used directly for hemoglobin formation. Since that time a number of workers have studied factors affecting hemoglobin production in rats rendered anemic by whole milk diets. Most of this work has verified the original conclusions concerning the importance of copper, and today, although there are some who still feel that copper is not the only element in addition to iron which possesses hematopoietic properties, practically all workers agree that copper is an active agent in hemoglobin synthesis. In most of these studies the activity of copper has been measured by comparing the increase in the hemoglobin content of the blood of anemic rats when pure iron alone is fed. with the improvement obtained when the iron is accompanied by traces of copper. Aside from. the fact that the hemoglobin molecule does not contain copper (2), nothing is known about the action of this element. In other words, we know that copper is necessary for the production of the finished blood pigment, but we have no understanding of how it functions in this interesting synthesis. In this paper we wish to present the results obtained when special emphasis was placed on the action of copper on the storage and utilization of iron in the animal body. Since the liver and