Uptake of mercury and mercury-amino acid complexes by rat renal cortex slices.

Abstract

This study was undertaken in order to assess the effects of metabolism and complexations with amino acids on the renal uptake of mercury using rat renal cortex slices as the experimental system. Mercury levels attained in the slices after 60 min of incubation were 50% higher with mercuric cysteine than with mercuric chloride. This enhancement of uptake with mercuric cysteine was reduced in the presence of a tenfold molar excess of histidine or lysine, but not by serine. Excess cysteine markedly increased mercury uptake. Incubation at 25 degrees significantly reduced uptake of mercuric cysteine, but not mercuric chloride. Anaerobic conditions and incubation in the presence of DNP each reduced mercuric cysteine uptake to the control level of mercuric chloride without affecting uptake of mercuric chloride. The differential aspects of metabolism on the uptake of mercuric cysteine and mercuric chloride and the competitive effects obtained with amino acids known to compete with cysteine in renal reabsorption support the hypothesis that a portion of the renal uptake of mercury operates through amino acid transport mechanisms acting on mercury-amino acid complexes.