Whole-body retention

Inaba, J. and LenGEMAnn, F. W. (1972). Intestinal uptake and whole-body retention of 144Ce by suckling rats, Health Phys. 22,169. 

The retention of selected isotopes by amphibians and reptiles is quite variable. For example, whole-body retention of after intraperitoneal injection in the rough-skinned newt showed two distinct loss components with biological half-lives of 2 and 210 days. The slower component accounted for 26% of the administered activity thyroid contained 78% of the total and clearly accounted for the long-term component (Willis and Valett 1971). However, similar studies with 1 and the leopard frog showed three distinct loss components (0.1 day 1.4 to 2.9 days 44.3 to 69.4 days) loss of each component was greater at 25°C than at 10°C. Also, the fast component probably represented plasma clearance through urinary excretion (Willis and Valett 1971). 

Whole body retention studies in mice, rats, monkeys, and dogs following intravenous injection of radiolabeled silver nitrate indicate that silver excretion in these species follows a triexponential profile (Furchner et al. 1968). For mice and monkeys, this differs from the biexponential profile seen following oral exposure. Whole body clearance following intravenous exposure was slower than clearance following oral exposure in each of the four species observed. In addition, the difference in clearance rate between species was more dramatic. Clearance at 2 days post-exposure ranged from 15% in the dog to 82% in the mouse (see Table 2-5) (Furchner et al. 1968). 

Following intravenous administration of radium-224 to elderly human subjects (63 to 83 years), the excretion of radium was primarily via the feces, with fecal to urinary ratios of about 30-to-1 usually observed (Maletskos et al. 1966, 1969). Although these observations suggest that biliary excretion is involved, no data are available to verify that assumption. The whole body retention was about 15% after 20 days. 

Cuddihy RG, Griffith WC. 1972. A biological model describing tissue distribution and whole-body retention of barium and lanthanum in beagle dogs after inhalation and gavage. Health Phys 23 621-633. 

Whole Body Retention of 52inc from Defatted Soy Flour, Acid... 

The meals were extrinsically labelled by added 65 Zn. The rationale for this method is that a complete isotope exchange takes place between the added radioactive zinc isotope and the zinc present in the meal. Measurements of the uptake of radioactive iron isotopes in blood or in the whole body have been used for many years in studies of iron absorption. (12, 13, 14). The absorption in the present study is determined from measurement of the whole body retention of the radioisotope. However, this can not be done until the non-absorbed fraction of the isotope has left the body. During this periode of time some of the initially absorbed has been extrected. A correction of retention data... 

Different forms of lanthanide differ in their toxicity. There are three forms of lanthanides soluble (chlorides, nitrates, acetates), insoluble (oxides, carbonates), and chelated compounds (DTPA). Most of the available information on lanthanide absorption and toxicity comes from the soluble lanthanide salts. In one study, rats given DTPA (chelating agent) 1 or 2 days after oral administration of cerium chloride were found to have significantly reduced whole body retention of soluble cerium (from 40% to 2%). 

Nielsen JB, Andersen O. 1991b. Methyl mercuric chloride toxicokinetics in mice II. Sexual differences in whole-body retention and deposition in blood, hair, skin, muscles and fat. Pharmacol Toxicol 68(3) 208-211. 

Possibly induced by bile acid ... . I selenohomocholyltaurme. .. whole body retention or . serum 7a-hydroxy-4- V. cholestcn -3 one . 

Brydon WG, Nyhiin H, Eastwood MA, Merrick MV. Serum 7a-hydroxy-4-cholesten-3-one and selenoho-mocholyltaurine (SeHCAT) whole body retention in the assessment of bile acid induced diarrhoea. Eur J Gastroenterol Hepatol i996 8 117-23. 

Two studies indicated that the addition of milk to rodent diets increases the total body burden of Hg as well as Hg concentrations in the brain (Landry et al. 1979 Rowland et al. 1984). Landiy et al. (1979) showed a 56% increase in the whole-body retention of Hg in female BALB/c mice fed liquid diets of evaporated whole milk as compared with their standard diet. That increase was attributed to the binding of heavy metals to the milk triglycerides, enhancing gut absorption. Those findings of an increased retention of MeHg with a diet containing evaporated milk were confirmed by Rowland et al. (1984). 

In humans, whole body retention studies following oral administration of sodium selenite have indicated that selenium elimination is triphasic (Thomson and Stewart 1974). During the initial phase, which lasted about 1 week, elimination of selenium was rapid, with a half-life of approximately 1 day (Thomson and Stewart 1974). In the second phase, which also lasted approximately 1 week, selenium elimination was slower, with a half-life of 8-9 days. In the third phase, selenium elimination was much slower, with a half-life estimated to be 115-116 days. The first two elimination phases correspond to the fecal elimination of nonabsorbed selenium and the urinary excretion of absorbed but unutilized selenium (Thomson and Stewart 1974). Selenomethionine elimination is also triphasic however, its terminal half-life is longer than that of sodium selenite. The average half-lives of selenomethionine for the three phases were measured to be approximately 0.4-2, 5-19, and 207-290 days, respectively (Griffiths et al. 1976). 

Burk RF, Brown DG, Seely RJ, et al. 1972. Influence of dietary and injected selenium on whole-body retention, route of excretion, and tissue retention of (75Se03)-2 in the rat. J Nutr 102 1049-1055. 

Chmielnicka J, Hajdukiewica Z, Komstra-Szumska E, et al. 1978. Whole-body retention of mercury and selenium and histopathological and morphological studies of kidneys and liver of rats exposed repeatedly to mercuric chloride and sodium selenite. Arch Toxicol 40 189-199. 

Tracer in milk Adults (5) 11 Healthy subjects. Dose administered in milk, daily for 21-32 days. Absorption estimated from whole body retention kinetics. Rundo and Lilligraven 1966... 

Flavones. In rats given doses of flavone (Ipriflavone, 7-isopropyl-isoflavone, or Morin, 2, 2,4, 5,7-pentahydroxy-flavone) for 3 weeks prior to acute oral exposure to radiostrontium, the whole body retention of radiostrontium was reduced by 50 and 30%, respectively after 1 month (Gachalyi et al. 1988). Similar experiments on pregnant rats demonstrated that both flavones reduced fetal uptake of radiostrontium administered to dams on gestational days 17/18 and 19/20. No studies were located that demonstrated the usefulness of flavones for emergency situations, rather than as pretreatments. 

Anderson JJB. 1972. Whole-body retention of single injections of 85Sr in swine and dogs as a function of age A review. In International Conference on Strontium Metabolism, ed. Second international conference on strontium metabolism, Glasgow and Strontian, 16-19 August, 1972. TID 4500 59th ed. Health and Safety Laboratory / U.S. Atomic Energy Commission, 31-38. 

Anderson JJB, Balk MW, Crackel WC, et al. 1971a. Effects of calcitonin on 85Sr whole body retention in the dog. Nature (London) New Biol 232 93-94. 

Keslev D, Van Puymbroeck S, Van Der Borght O. 1972. Effect of aluminum phosphate gel on whole-body retention of simultaneously administered 226Ra, 85Sr and 47Ca in mice. Experientia 28(5) 524-525. 

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