Studies on the Relation of Manganese to the Nutrition of the Mouse*

There are a number of minor inorganic elements constantly found in animal tissues whose function, or even necessity, is still in question. Among such elements are manganese, zinc, cobalt, and nickel. In the last few years the necessity for copper as a supplement to iron in hemoglobin building has been firmly established (1). After this relationship had been demonstrated a number of investigators reported results indicating that manganese could also function like copper in hemoglobin building. Our own work (2), as well as the work of Krauss (3), Lewis et al. (4), and others, has not confirmed these claims. In fact, Titus, Cave, and Hughes (5), who first announced this possible relation of manganese to hemoglobin synthesis, have been unable to confirm their earlier results (3). While it may be admitted, therefore, that manganese has no relation in the mammal to hemoglobin building, yet its constancy in animal tissues (6) makes it very probable that it does perform some essential function. Recent work by Richards (7) indicates a wide distribution of manganese in both plant and animal materials with a special accumulation of this element in the reproductive organs. While Richards makes no claims to the indispensability of manganese for normal growth and development, yet she considers it very possible that manganese may have a significant physiological action, particularly in relation to the normal performance of the reproductive organs. In order to supply direct experimental evidence that manganese