404 ZINC-BINDING LIGANDS IN DUODENAL JUICE AND SALIVA FROM NORMAL ADULTS AND ACRODERMATITIS ENTEROPATHICA PATIENTS

Abstract

Acrodermatitis enteropathica (AE) is an autosomal, recessively inherited disease, the pathogenesis of which is attributable to severe zinc deficiency. Before the introduction of oral Zn therapy some AE patients were treated effectively with breast milk. A zinc-binding ligand (ZBL) which may facilitate the absorption of Zn has been found in human milk (but not cow's milk) and in rat small intestine (Hurley et al., Proc. Nat. Acad. Sci., 1977). A similar ZBL may be present in human duodenal juice and an absence or defect in such a ligand could be one site of the molecular defect in AE. Samples of duodenal juice and mixed saliva from normal subjects were fractionated by gel chromatography on Bio-gel P-10. Most of the Zn eluted from the column in two peaks, one at the void volume and one at lower molecular weight. The second peak was further purified by electrophoresis on acrylamide gel and found to contain a ZBL similar in size to that in breast milk. Pancreatic juice and saliva from 3 AE patients also contained the ZBL. It is concluded that the ZBL is present in some cases of AE but it is not yet known if it is normal in quantity or quality. (Supported in part by NIH Postdoctoral Fellowship no. HD-07096 and USPHS Grant no. ROl-AM-12432.)