A study on the biochemical and biological behavior of methylmercury.

The biochemical and biological behavior of methylmercury (MeHg) was investigated by measurement of MeHg release rate from erythrocytes (RBC) of selected animal strains and species, by measurement of the intracellular distribution of MeHg in RBC, and by measurement of the binding affinity of hemoglobin (Hb) for MeHg. Methylmercury chloride was used throughout the experiments. Significant strain and species differences were found in the release rate of MeHg from RBC of mice, rats, and man and in the distribution of MeHg in RBC. Significant correlations were found between the above two indexes and the brain/blood ratio of mercury concentration 24 hr after MeHg injection, ip. The affinity of Hb for MeHg was examined by ultrafiltration techniques and Scatchard plots. There were Hbs with only one type of binding site and others with two types of binding sites. Both sites were considered to be cysteinyl residues. Primary sites involved cysteinyl residues oriented externally at the outside of the alpha 1 beta 1 contact junction and cysteinyl residues in the junction, while secondary sites involved only cysteinyl residues in the junction.