Radioactive multitracer technique was applied to study the brain regional uptake of trace elements by the normal mice during aging. The brain regional radioactivities of 46Sc, 54Mn, 65Zn, 75Se, 83Rb and 88Zr were measured 48 hours after intraperitoneal injection of a solution in normal mice aged 6 to 52 weeks to evaluate the brain regional (corpus striatum, cerebellum, cerebral cortex, hippocampus, and pons and medulla) uptakes. The radioactive distributions of 46Sc, 54Mn and 88Zr tracers were variable and region-specific in the brain, while those of 65Zn, 75Se and 83Rb tracers were comparable among all regions of interest. The brain regional uptakes of all tracers slightly increased with age from 10 to 28 weeks, and then remained constant during aging after 28 weeks. These uptake variations may be involved in the functional degenerative process of the blood-brain barrier during aging.
Authors:T. Ozaki, S. Ambe, S. Enomoto, Y. Minai, and Y. Makide
The effect of ZnCl2 on the uptake of Be, Na, Mn, Co, Zn, Se, Rb, Sr, Rh, Cs and lanthanoids (Ce, Pm, Gd and Lu) by carrot (Daucas carota cv. U.S. harumakigosun) was investigated. Uptake was measured using a multitracer technique which enables to acquire information
about various elements under identical conditions. The amount of uptake of Rb, Cs, Sr, Mn and Co, into roots decreased with
increasing concentration of ZnCl2. On the other hand, little effect was observed for the uptake of Be, Se, Rh and lanthanoids. These results suggest that Rb,
Cs, Sr, Mn and Co competed antagonistically with Zn for the binding sites of carriers in the roots, while there was no influence
on the uptake of the other elements. Uptake of Se was not influenced by Cl added as ZnCl2. It is concluded, therefore, that carrot can distinguish Se from Cl based on the physicochemical differences between these
two anion species.
Authors:S. Oishi, R. Amano, A. Ando, S. Enomoto, and F. Ambe
The radioactive multitracer technique was applied to a study on the uptake of trace elements in normal C57BL/6N mice. Comparative
uptake behavior of46Sc,54Mn,59Fe,58Co,65Se,83Rb and88Zr tracers was examined among 11 organs (brain, cardiac muscle, lung, liver, spleen, pancreas, kidneys, bone, muscle, eyeballs
and testes) and blood, and evaluated in terms of the “tissue uptake rate (the radioactivity percentage of injected dose per
gram of tissue, %dose/g)”. The multitracer technique revealed reliable data demonstrating characteristic uptake of the 8 trace
elements, Sc, Mn, Fe, Co, Zn, Se, Rb and Zr by the brain and other organs, as well as the distinctive features of the accumulation
and retention of each element in the brain.
Authors:B. Liu, S. Ambe, S. Enomoto, R. Weginwar, and F. Ambe
Radioisotopes of 37 elements were isolated from a gold target irradiated with an energetic12C beam and were used as a multitracer to establish procedures for separating themselves into groups of carrier-, salt-and organic matter-free tracers. Solvent extraction with HDEHP and ethyl methyl ketone along with cation exchange yielded group tracers ready for application to chemical and biological studies.
Labeling of antibodies, immunoglobulin G (IgG), with a multitracer was investigated with the aim of its utilization in the preparation of radiopharmaceuticals. The labeling procedure consists of two steps: conjugation of diethylenetriaminepentaacetic acid (DTPA) cyclic dianhydride with IgG and subsequent labeling with the multitracer.
Authors:Y. Oura, S. Enomoto, H. Nakahara, H. Matsue, and C. Yonezawa
Prompt -ray analysis with the internal monostandard method was used to organs taken from rats. After B or Cd was administered, the B/H and Cd/H contents ratios were determined in the brain, kidney, and liver to study their distribution and metabolism. Boron was distributed in all organs but metabolized quickly. Cd was slowly accumulated in the liver and kidneys during the 65 hours studied but no Cd was detected in the brain.
Authors:K. Matsumoto, I. Ui, R. Hirunuma, S. Enomoto, and K. Endo
Time series of the distribution of bio-trace elements in the upper abdomen of living rats were examined using the in vivo multitracer analysis technique. The in vivo dynamics of the elements were estimated by comparison with the distribution of 74As. Vanadium, Mn, Fe, Co, Zn, Se, and Rb were distributed in tissues of the upper abdomen, i.e., mainly in the liver. Be, Sr, and Y might be in the blood or bone at a low level and in the excretion stage already. Dynamics of bio-trace elements were noninvasively obtained in a living rat within one hour after administration.
Authors:Y. Yabushita, Y. Kanayama, T. Tarohda, R. Amano, and S. Enomoto
Radioactive multitracer technique was applied to study the screening of in vivo interrelations between radioactive tracers (46Sc, 59Fe, 58Co, 65Zn, 75Se, 83Rb, 85Sr and 88Zr) and stable Mn species. Comparative uptake rates were examined in the blood, 9 organs (thymus, lung, cardiac muscle, spleen, pancreas, kidney, liver, testes and bone) and 8 brain regions (cerebral cortex, striatum, hippocampus, thalamus and hypothalamus, midbrain, cerebellum, pons and medulla, olfactory bulb) using the 3-weeks-old mice fed the Mn-deficient, -adequate or -excessive diets with Mn concentration from 0.4 to 300.4 ppm. Significant diet-related differences were found for 65Zn uptake in some organs. The dietary Mn-deficient state induced increase Zn absorption in thymus and lung in short-time span (during 48 hours after injection). On the other hand, no significant diet-related differences were observed in any brain regional uptake rates except for 54Mn uptake rate. The screening results are expected to give us new findings concerning the diet-related element-element interrelations in living bodies.
Authors:Y. Yabushita, Y. Kanayama, T. Tarohda, S. Enomoto, and R. Amano
Radioactive multitracer technique was applied to study the screening of in vivo interrelations between radioactive tracers (46Sc, 54Mn, 58Co, 65Zn, 75Se, 83Rb, 85Sr and 88Zr) and stable Zn species. Comparative uptake rates were examined in the blood, nine organs (thymus, lung, cardiac muscle, spleen, pancreas, kidney, liver, testes and bone) and eight brain regions (cerebral cortex, striatum, hippocampus, thalamus and hypothalamus, midbrain, cerebellum, pons and medulla, olfactory bulb) using 3-week-old mice fed by four kinds of Zn-deficient, -adequate and -excessive diets with Zn content from 0.7 to 3520 ppm. As a result, no significant difference between the dietary Zn-deficient state (Zn content: 3.6 ppm) and Zn-adequate state (Zn content: 36 ppm) was observed in the uptake rates of 65Zn and other 46Sc, 54Mn, 58Co and 75Se, except for 83Rb. In addition, significant differences among the organ and brain regional uptakes of 46Sc, 54Mn, 58Co, 75Se and 83Rb were found in the dietary Zn-excessive state (Zn content: 3520 ppm). These results indicate that the organ and brain regional uptakes of tracers in Zn-deficient and excessive mice are strongly correlated with the blood uptakes and retentions of the tracers. Furthermore, the multitracer screening gives us new findings concerning the diet-related element-element interrelations in living bodies.
Authors:T. Shinonaga, S. Ambe, S. Enomoto, H. Maeda, M. Iwamoto, T. Watanabe, and I. Yamaguchi
The direct absorption of atmospheric elements via soybean leaves has been studied using a radioactive multitra r technique. Soybean was cultivated until it bore seeds in a box under no-rain conditions and with introduction of multitracer-adsorbed cellulose powders. The radioactive nuclides of 40 elements were produced from Au target irradiated with14N, and the nuclides with relatively long half-life of the elements Sc, Mn, Co, As, Se, Rb, Sr, Y, Eu, Gd, Yb, Re, and Ir were dominantly observed in each part of soybean plant.