Studies in Iron Transportation and Metabolism. Ii. The Mechanism of Iron Transportation: Its Significance in Iron Utilization in Anemic States of Varied Etiology 1

The Anemia of Infection. Vii. The Significance of Free Erythrocyte Protoporphyrin, Together With Some Observations on the Meaning of the “Easily Split-Off” Iron 1

“…The variations in plasma iron observed in our studies correspond to those described by others (34). An increase in plasma iron may result from its release from hemoglobin during blood destruction; rapid blood formation, however, leads to an increased demand for iron which in turn tends to deplete the amount in the plasma.…”

Studies in Iron Transportation and Metabolism. Iv. Observations on the Absorption of Iron From the Gastro-Intestinal Tract 12

“…The [5][6]1937, and in part before the Sixteenth International Physiological Congress, Zurich, August [14][15][16][17][18][19][20][21]1938. 2 The authors wvish to express their appreciation to John T. Read the iron which may be absorbed and then excreted into the colon (18). McCance and Widdowson have, however, presented evidence which tends to show that such excretion is minimal (19).…”

“…This approach became possible only after it had been demonstrated that iron is transported as plasma or serum iron (2,4). Its use is dependent upon a knowledge of the forms and 553 relationships of iron in the blood.…”

“…Demonstration has already been made of the facts that: (1) under basal conditions of iron intake and utilization, hourly variations in the serum iron level are comparatively slight (3); and (2) following the oral administration of a single large dose of various of the iron salts, there is a prompt rise in the serum iron fraction (2). This increase is apparent within the first half hour, reaches its maximum in 21/2 to 5 hours, and then gradually falls to approximate the basal level by the end of 12 hours.…”

Studies in Iron Transportation and Metabolism. Iii. The Normal Fluctuations of Serum and “Easily Split-Off” Blood Iron in Individual Subjects

“…It has been demonstrated, in the first place, that plasma iron is of metabolic importance in that it serves as the medium for iron transportation in the mammalian organism (2,3,4,5). This concept has made possible a more direct approach to the analysis of the factors controlling iron absorption since an index of the amount of iron being absorbed from the intestinal tract under standard conditions can be gained by measuring increases in plasma iron (2,6,7).…”