Kinetics of zinc metabolism: Variation with diet, genetics and disease

Kinetic studies are used to investigate metabolic processes. By adding an i sotope to a system and measuring its movement in the system over time, pool sizes and transport rates can be determined by mathematically modeling the data. This approach enables rate differences to be determined in condition s that have been modified by diet, environment, genetics or disease. Kineti c studies in humans have shown that there are multiple pools of zinc that t urnover from minutes to years and that processes, including zinc absorption and excretion, are regulated to maintain tissue levels when zinc intake va ries. Animal studies allow for greater understanding of kinetics because mo re tissues can be sampled and environmental and genetic factors can be cont rolled. Kinetic studies in animals will provide information on the overexpr ession or the deletion of genes coding for specific proteins involved in zi nc transport and metabolism. The advances that have been made in our unders tanding of the role of zinc in metabolism have been aided by the developmen t of techniques for measuring isotopes in biological materials. In the futu re, the kinetics of zinc bound to different compounds will be measured, Mod eling will enable this information, at the molecular level, to be integrate d with knowledge of zinc metabolism at the cellular, organ and whole body l evel. To understand more fully the role of zinc in human health, kinetic st udies are needed in healthy and disease states to identify differences in m etabolic processes. This knowledge can be used as a basis for dietary and t herapeutic recommendations.