THE USE OF STABLE-ISOTOPE TECHNIQUES TO ASSESS ZINC-METABOLISM

The refinement of techniques that can accurately measure small changes in zinc stable isotope ratios in biological samples provides new opportunities for advancing our understanding of human zinc metabolism. The feasibility of utilizing more than one zinc stable isotope label simultaneously is invaluable for more complex kinetic studies. These techniques are especially valuable for investigations of the regulation of Zn homeostasis in infants and in women during the reproductive cycle in whom problems with zinc nutriture may be relatively frequent and of concern for pre- and postnatal growth and development. Initially, these techniques have been applied to studying the role of the intestine in the maintenance of zinc homeostasis and have served to emphasize the importance of the modulation of fecal excretion of endogenous zinc. Application of stable isotope techniques to explore zinc metabolism beyond the intestinal tract is still limited but has considerable potential for advancing our understanding of zinc metabolism in health and disease.