Relative zinc-binding activities of ligands in the cytosol of rat small intestine

Abstract

1. Relative zinc-binding activities of high-molecular-weight zinc-binding ligand (HMW-ZBL), metallothionein (MT) and low-molecular-weight zinc-binding ligand (LMW-ZBL) in the cytosols of rat small intestines under various experimental conditions were examined. 2. Zinc-binding activities of MT decreased and those of LMW-ZBL increased in the intestinal cytosols from most of the experimental rat groups after incubating at 37°C for 2 hr. 3. The relative zinc-binding activity of MT increased with increasing doses of injected zinc and decreased with orally-administered zinc. 4. Isolated MT did not lose zinc-binding activity during incubation at 37°C for 48 hr, but moved from the MT eluting peak to the LMW-ZBL eluting peak after 1 week.