UPTAKE OF STABLE ISOTOPES AS A METHOD OF LABELING HAIR (COPPER, IRON, ZINC).

摘要

Hair growth can be used to eliminate minerals from the body. Elements become metabolically inert when growing hair forms stabilizing bonds between protein chains. Consequently, hair reflects the metabolism, environmental history, and health of animals. Large variability in hair elemental concentrations occurs among animals and between similarly treated animals. That variation may be attributed to individual, physical, and external factors that cannot be controlled easily.;Copper-65 in rat hair from rats given natural copper differed significantly from those given enriched copper-65 by gastric injection. Change in the copper-65 fractional abundance in hair demonstrated that the copper-65 was absorbed, was incorporated into hair, and was suitable as a chemical label. The reason that copper-65 as an additive to the feed was unsuccessful at chemically labeling hair is unknown. Copper-65 values in hair from rats administered natural copper in their feed or by gastric injection did not differ statistically from each other or the controls, as expected. Neutron Activation Analysis-Direct Current Argon Plasma Emission spectroscopy techniques were much less precise compared to Inductively Coupled Argon Plasma Emission Spectroscopy-Mass Spectrometry. The nonradioactive isotope tracer technique developed in this study can correlate elements that deposit in hair to those that deposit in body tissues (bone, brain, kidney, and liver) for studying bioavailability of foods or drugs, to follow multiple complex metabolic reactions in vivo, correlating element uptake with disease, or studying the utilization of elements in mammals.;Nearly pure (0.9906) nonradioactive copper-65 isotope and natural copper (0.3091, copper-65 and 0.6919, copper-63) were administered by daily gastric injection or as an additive to the feed to laboratory rats for 28 consecutive days. Analyses of copper-65 were determined by Neutron Activation Analysis (NAA), total copper by Direct Current Argon Plasma Emission Spectroscopy (DCP), and the Cu-63/Cu-65 ratios by Inductively Coupled Argon Plasma Emission Spectroscopy-Mass Spectrometry (ICP-MS).