Zinc-binding ligands in milk and intestine: a role in neonatal nutrition?

Abstract

The hypothesis that a Zn-binding ligand [ZBL] which may be the factor responsible for the therapeutic value of human milk in the genetic Zn metabolic disorder, acrodenmatitis enteropathica] recently discovered in human milk but absent from cow''s milk might be related to Zn nutrition in the neonate was investigated. The Zn-binding characteristics of rat milk were examined to determine if the rat was a suitable model. By gel filtration, rat milk was found to contain a ZBL with characteristics similar to those of the ZBL found in human milk. A similar ZBL was identified in the intestinal mucosa of rats 16 days of age and older but was absent in rats from birth to 16 days. The ZBL of maternal milk may enhance Zn transport in the neonatal period before the development of intestinal mechanisms for Zn absorption.