title: Octanol/water partition coefficients as a model system for assessing antidotes for methylmercury(II) poisoning, and for studying mercurials with medicinal applications.
abstract: 1-Octanol/water partition coefficients, [HgII]octanol/[HgII]water, provide a simple but limited model system for aspects of the biological behavior of methylmercury(II) and commonly used organomercury(II) medicinal compounds. In an octanol/water system some widely studied antidotes for mercury poisoning at least partly displace the biological thiols L-cysteine and glutathione from binding to MeHgII at pH 6.9. Addition of the antidote meso-dimercaptosuccinic acid to MeHgII in the presence of glutathione results in formation of metallic mercury. For RHgII derivatives of L-cysteine and glutathione, octanol/water partition coefficients follow the order Ph greater than Et greater than Me. An exceptionally high value for diphenylmercury, compared with PhHgII derivatives of L-cysteine and glutathione, is consistent with reported results of the distribution of mercury compounds in rats. Ethylmercury(II) is partly displaced from thimerosal by L-cysteine and glutathione in the octanol/water system, indicating that the active form of thimerosal in vivo may involve binding of EtHgII to biological ligands.
mesh_terms: D000818:Animals; D000931:Antidotes / Q000378:metabolism; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003545:Cysteine / Q000378:metabolism; D005035:Ethylmercury Compounds / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D008767:Methylmercury Compounds / Q000378:metabolism / Q000506:poisoning*; D008954:Models, Biological; D000442:Octanols; D009941:Organomercury Compounds / Q000378:metabolism; D010663:Phenylmercury Compounds / Q000378:metabolism; D051381:Rats; D004113:Succimer / Q000378:metabolism; D014867:Water
chemical_list: D000931:Antidotes; D005035:Ethylmercury Compounds; D008767:Methylmercury Compounds; D000442:Octanols; D009941:Organomercury Compounds; D010663:Phenylmercury Compounds; D014867:Water; D004113:Succimer; D005978:Glutathione; D003545:Cysteine