Radioactive Iron and Its Excretion in Urine, Bile, and Feces

Hahn, P. F.; Bale, William F.; Hettig, Robert A.; Kamen, Martin D.; Whipple, G. H.

doi:10.1084/jem.70.5.443

Cited by 103 publications

(19 citation statements)

References 7 publications

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“…Cumulative urine collections in three subjects contained less than 1 per cent of the administered dose. This confirmed in humans the previous ohservations in animals that significant quantities of radioactive iron are not excreted in the urine (13,14 …”

Section: Resultssupporting

confidence: 81%

Iron Absorption. Measurement of Ingested Iron59 by a Human Whole-Body Liquid Scintillation Counter

Hoek¹,

Conrad²

1961

J. Clin. Invest.

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The availability of radioactive isotopes of iron led to the development of reliable methods of studying iron kinetics (1), but the absorption of iron by the gastrointestinal tract was still determined indirectly by the amount of unabsorbed iron excreted in the stools or by quantification of isotopic iron incorporated into hemoglobin (2-7). The availability of a whole-body counter in a clinical facility has made possible the direct assay of iron59 retention in human subjects and has eliminated sample collecting and preparation. The purpose of this paper is to describe this method and demonstrate some of the findings. METHODS AND MATERIALSThirty-five volunteers, 25 normal and 10 iron-deficient adults, were the subj ects of the study. The iron-deficient subjects met one or more of the following criteria: 1) virtual absence of iron in bone marrow smears stained by the Prussian-blue reaction (8) ; 2) serum iron less than 70 Ag per 100 ml with total iron-binding capacity in excess of 350 jig (9, 10) ; 3) recent loss of blood without replacement by iron or transfusion. Five subjects (Tables IV and V, numbers 1, 3, 4, 7 and 9) had been purposely phlebotomized to induce iron deficiency. They were in various stages of recovery following the loss of 4 or 5 units (2.0 to 2.5 L) of blood in a period of 1 month. In Subjects 4 and 9 the peripheral parameters had become normal at a time when one could be sure from the history, amount of blood loss and the lack of iron in the marrow, that the body iron stores had not been replenished.The normal iron-replete subj ects met none of these criteria. Serum iron was in excess of 80 ,ug per 100 ml; there was no evidence of bleeding or history of recent blood loss. Red cell indices were established in all subjects. None of the subjects was known to have neoplastic, infectious or inflammatory disease.Iron absorption studies were performed in each subject with radioactive iron' and a whole-body liquid scintillation counter. The instrument was a 47r liquid scintillation counter simliar in design to the Los Alamos counter (11). The major differences were an increase in diameter of the sample well to 20 inches and the substitution of thirty 5-inch photocathode tubes. This instrument was operated as a two-channel analyzer, specifically to detect body cesium.. and potassium' with maximal efficiency. The two ranges of -y-energy discrimination were wide (0.3 to 0.8 and 0.8 to 2.0 Mev) and useful for detecting a large number of y-emitting nuclides with good efficiency.The standards used were a 2.5 L water-filled plastic bottle to which iron" was added in amounts equal to half the dose given the subject. A 250 ml plastic bottle similarly prepared was used as a standard for measurement of radioactivity in feces.Prior to administration of the radionuclide, the volunteers were assayed in the body counter. They lay supine on a canvas sling within the sample chamber (Figure 1).

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Section: Resultssupporting

confidence: 81%

Iron Absorption. Measurement of Ingested Iron59 by a Human Whole-Body Liquid Scintillation Counter

Hoek¹,

Conrad²

1961

J. Clin. Invest.

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“…With further reference to the fate of plasma iron diverted in the presence of inflammation, it may be pointed out that Hahn et al (12) showed that the urine and bile contain negligible quantities of iron injected intravenously in doses even larger than those used in the present study. In balance studies, Schaefer (13) found no evidence of increased excretion of iron in children with infection.…”

Section: Discussionmentioning

confidence: 65%

The Anemia of Infection. V. Fate of Injected Radioactive Iron in the Presence of Inflammation 1

Greenberg¹,

Ashenbrucker²,

Lauritsen³

et al. 1947

J. Clin. Invest.

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Since hypoferremia is so consistently associated with the anemia of infection (1), and since injected iron appears to be diverted from the plasma in infection (1, 2), it seemed desirable to determine the fate of the diverted iron.In this study, radioactive iron was injected intravenously into normal rats and in rats with acute inflammation. The blood and tissues were then analyzed after a period of time for radioactivity. Preliminary studies were made in which only the blood and liver were analyzed in order to determine the appropriate amount of iron to employ. Radioactive iron was also injected intravenously into dogs, and analyses were carried out on a number of tissues, including the exudates. METHODSThe radioactive iron used in these studies was injected as ferric chloride in physiological saline. For the rats, the concentration was adjusted so that about 0.2 ml. was injected for each 100 grams body weight. In all the rats the same tuberculin syringe was employed for this purpose. In order to be certain that the solution did not enter subcutaneously, the vein on the lateral aspect of the tail was exposed under nembutal anesthesia and the solution was injected intravenously. In one experiment Fe was injected intraperitoneally.Inflammation was produced by the intramuscular injection of 0.5 ml. of turpentine. Robscheit-Robbins and Wlhipple (3) have shown that the resulting sterile abscess can be compared with a bacterial abscess. In some animals, 0.5 ml. of a mixed culture of S. aureus and E. coli was injected intramuscularly. Injections of bacteria or turpentine were made about 2 hours before Fe was administered.The methods for preparing and electroplating the Fe from the biological samples have been described elsewhere (4). Blood volume was estimated by assuming that the normal mammal possesses 80 ml. blood per kgm. body weight. Hemoglobin was determined in a representative sample of the tissue to be analyzed for radio-

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“…Iron loss arises from epithelial cell sloughing and minor bleeding and totals less than 2 mg per day on average (8). Because regulated iron excretion systems do not exist in humans, total body iron homeostasis is regulated at the level of dietary absorption (9,10). Dietary nonheme iron is ferric and must be reduced to the ferrous state for membrane transport.…”

Section: Iron Homeostasis In Humansmentioning

confidence: 99%

Sequestration and Scavenging of Iron in Infection

2013

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The proliferative capability of many invasive pathogens is limited by the bioavailability of iron. Pathogens have thus developed strategies to obtain iron from their host organisms. In turn, host defense strategies have evolved to sequester iron from invasive pathogens. This review explores the mechanisms employed by bacterial pathogens to gain access to host iron sources, the role of iron in bacterial virulence, and iron-related genes required for the establishment or maintenance of infection. Host defenses to limit iron availability for bacterial growth during the acute-phase response and the consequences of iron overload conditions on susceptibility to bacterial infection are also examined. The evidence summarized herein demonstrates the importance of iron bioavailability in influencing the risk of infection and the ability of the host to clear the pathogen.

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Radioactive Iron and Its Excretion in Urine, Bile, and Feces

Cited by 103 publications

References 7 publications

Iron Absorption. Measurement of Ingested Iron59 by a Human Whole-Body Liquid Scintillation Counter

Iron Absorption. Measurement of Ingested Iron59 by a Human Whole-Body Liquid Scintillation Counter

The Anemia of Infection. V. Fate of Injected Radioactive Iron in the Presence of Inflammation 1

Sequestration and Scavenging of Iron in Infection

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