Cellular uptake and subcellular distribution of mercury in chick embryonic retinal cell aggregates

Cellular uptake and subcellular distribution of mercury (203HgCl2) were determined in the chick embryonic retinal cell aggregation system. The accumulation of mercury was dependent upon its concentration in the medium. The uptake was rapid; a maximum deposition of mercury at 5 microM occurred within the first 30 min followed by a decline. Accumulation of mercury at 1 microM was constant between 15 min and 24 hr. The subcellular distribution of mercury was observed in the following order: nuclei and cell debris greater than mitochondria-lysosomes greater than 105,000g supernatant greater than microsomes. The activity of acid phosphatase markedly decreased in the aggregates treated with mercury at 50 to 100 microM for 24 hr. Low concentrations of mercury at 0.5 to 5 microM showed an inhibition of this enzyme activity in a cell-free system. The results indicate a relationship between the amount of mercury in the cells and the toxicity it produced on the retinal cell aggregation system.