The Influence of Selenium on Methyl Mercury Toxicity in Rat Hepatoma Cells, Human Embryonic Fibroblasts and Human Lymphocytes in Culture

Abstract

The effect of methyl mercury and two selenium compounds have been studied in cell cultures. Methyl mercury in concentrations above 1 μM had a pronounced inhibiting effect on the growth of rat Morris hepatoma cells. Glucose and lactate uptake in relation to cell protein was appreciably stimulated by the organic mercury compound. Selenite in low concentrations (0.5 μM) and seleno-di-N-acetyl glycine in thousandfold higher concentrations offered considerable protection against these effects of methyl mercury. The same selenite concentration (0.5 μM), which did not affect cell growth, caused an appreciable protection against methyl mercury (6 μM), even if it was added 3 days after methyl mercury. The methyl mercury inhibited the growth of human embryonic fibroblasts and the DNA-synthesis in the human lymphocytes. However, no protective effect of selenite were observed in these cell types. These results suggest that selenium compounds exert their protective effects through cell specific processes rather than by a direct chemical reaction between selenite and methyl mercury.