title: Hepatobiliary transport and organ distribution of silver in the rat as influenced by selenite.
abstract: Bile from rats injected with 110mAgNO3 (1 micromol/kg) were fractionated on Sephadex G-15 revealing binding of silver to one high molecular weight substance and one low molecular weight substance eluting corresponding to the void volume and glutathione (GSH) respectively. Fractionation of AgNO3 and GSH mixed in vitro gave rise to a polynuclear complex and a 1 : 1 complex of Ag+-GSH which both eluted corresponding to silver in bile. Depletion of GSH in the liver by diethylmaleate (3.9 mmol/kg) caused a parallel decrease in the biliary excretion of both silver and reduced GSH. These findings support the hypothesis that silver is excreted into bile by a GSH-dependent mechanism most likely using GSH as a carrier molecule. Selenite (1 micromol/kg) inhibited the biliary excretion of silver while AgNO3 (1 mumol/kg) did not influence the excretion of selenium into bile. Pretreatment with selenite (1 micromol/kg) also caused a retention of silver (AgNO3, 1 micromol/kg) in the blood, kidney and brain. The liver content of silver was decreased and the organ to plasma ratio of silver was unchanged for erythrocytes, but decreased for the brain, kidney and liver, respectively. The effects caused by selenite are attributed to the formation of Ag2Se complexes which are nearly water insoluble and probably unavailable for biliary excretion. Selenium metabolites (GSSeSG, GSSeH) which are excreted into bile are probably not available for complexing with Ag+.
mesh_terms: D000818:Animals; D001646:Bile / Q000032:analysis*; D001692:Biological Transport / Q000187:drug effects; D001921:Brain / Q000378:metabolism; D005260:Female; D007668:Kidney / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D020887:Selenious Acid; D012643:Selenium / Q000494:pharmacology*; D012834:Silver / Q000378:metabolism*; D012835:Silver Nitrate / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D012834:Silver; D012835:Silver Nitrate; D020887:Selenious Acid; D012643:Selenium