Copper absorption in healthy young men: studies with stable isotope 65Cu and neutron activation analysis

Abstract

1. A method based on Radiochemical Neutron Activation Analysis (RNAA) was developed to measure accurately fecal excretion of both stable isotopes ( 63Cu, 65Cu) of copper in human stools simultaneously. 2. It was shown that analysis of isotopic content of human feces could be carried out with analytical precisions (coefficient of variation) within ±1-2% which is necessary if stable isotopes of copper are to be employed in human metabolic studies. 3. Kinetics of fecal excretion of single or multiple doses of ingested 65Cu (enrichment 99.69%) were examined in four healthy young adults and it was shown that re-entry of the absorbed dose into the GI tract could be detected. 4. Limited data on absorption of 65CuCl 2 administered in the postabsorptive state were obtained for four healthy young adults and the results were discussed in relation to other reported values of copper absorption.