Pathological Iron Metabolism 91 



are injected, the organism attempts to react against the 

 invasion of iron by eUminating it through the kidneys and 

 fixing it transitorily in deposit organs hke the hver or in 

 tissues such as skin and muscles, which yield it back gradually 

 as the blood level of iron falls. The liver is the principal 

 organ of iron storage. The spleen does not participate 

 notably in this function, but on the other hand takes up iron 

 after haemolysis. More than 20 per cent of the iron is circu- 

 lating in the blood Ij hours after injection. Skin, muscles, 

 and bone marrow retain iron, whilst kidneys and intestine 

 excrete a certain quantity of the metal. These observations 

 confirm the results reported in numerous papers by 

 American authors on iron metabolism (Hahn, Balfour, 

 Whipple, etc.). 



We then followed the distribution of iron in pathological 

 erythropoiesis, engendered by anaemia due to repeated bleed- 

 ings, by maintaining the animal in a state of oxygen tension 

 corresponding to an altitude of 18,000 ft., by hyperthyroidism, 

 or by septicaemia. 



Table I gives the percentage of radioactive iron determined 

 in different organs IJ hours after injection (500 />tg.). 



In acute ancemia, the quantity of circulating iron is slightly 

 increased, the liver and skin contain strikingly less iron, whilst 

 iron in the bone marrow increases four or fivefold. This 

 experiment emphasizes the intense avidity for iron of the 

 bone marrow when there is increased erythropoiesis. 



In altitude hypoxemia (18,000 ft.), values are encountered 

 which approach those obtained in acute anaemia. Circulating 

 iron is slightly higher than in normal subjects and a high 

 proportion of the iron is fixed in the bone marrow, and also 

 in muscles, myocardium and nervous system. Apart from 

 the intense erythropoietic stimulation due to hypoxaemia, we 

 find a certain degree of fixation of iron in organs possessing a 

 high respiratory activity. 



The same phenomenon is also observed in hyperthyroidism, 

 where erythropoietic organs and also heart muscle, and to 

 some extent the liver, fix a significant quantity of iron. 



