Reliable quantitative studies of iron metabolism by the use of earmarked radioactive isotopes of natural iron were recently undertaken by Whipple and his co-workers1 of the University of Rochester. The radio iron used by these investigators was prepared in the University of California by bombardment of ordinary iron atoms (Fe58) with deuterons. The Fe59 thus formed decays slowly with the emission of beta rays, the half life of the isotope being forty-seven days, a sufficiently long time for metabolic studies. The amount of the isotope present in a given sample of tissue or body fluid is readily determined by measurement of its radioactivity (Geiger counter).
In their earlier experiments the Rochester physiologists2 found that in normal dogs the rate of absorption of ingested radioactive iron is practically nil, the iron being given in the form of neutral salts (e. g., ferric ammonium citrate). In a typical
METABOLISM OF RADIOACTIVE IRON. JAMA. 1942;120(17):1399–1400. doi:10.1001/jama.1942.02830520049013