Multitracer screening for in vivo element-element interrelations

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.