Zinc-Binding Protein: Relationship to Short Term Changes in Zinc Metabolism

Abstract

SummaryThe short-term changes in hepatic and intestinal mucosal zinc binding protein (ZnBP) bound Zn and in serum Zn concentration were investigated following either parenterally administered Zn or changes in dietary Zn. Both treatments resulted in similar changes in ZnBP-bound Zn. Repletion of Zn depleted rats resulted in increased hepatic and intestinal ZnBP-bound Zn and subsequent depletion decreased ZnBP-bound Zn in both tissues. These results demonstrate that ZnBP formation and degradation responds readily to fluctuations in dietary Zn level. Serum Zn was correlated to the appearance of ZnBP in both tissues and could be the metabolic signal that influenced the amount of Zn associated with ZnBP. The data suggest that ZnBP serves a regulatory function in zinc metabolism. Finally preliminary evidence suggests that ZnBP may be identical to me-tallothionein.