出版社：National Institute of Occupational Safety and Health
摘要：To investigate intracellular metal transport systems in the liver in vivo, male mice were given a single, intraperitoneal dose of Mn(CH3C00)2•4H2O (49 mg/kg), CuSO4•5H20 (6 mg/kg), K2Cr2O7 (15 mg/kg), or Pb(CH3COO)2•3H2O (38 mg/kg). High concentrations of Mn in the liver were rapidly recovered in both lysosomal and mitochondrial fractions and seemed to excrete into bile via liver lysosomes. The normal distribution of Ca in the subcellular fractions and bile was quite similar to that of excessive Mn. Following injection of Mn, Ca content in the liver mito-chondria increased but decreased in bile. Absorbed Cu, Pb, Cr and normal Zn in the liver were mainly recovered in the soluble fraction. Most absorbed Cu, Pb and normal Zn in the soluble fraction was bound to high-molecular-weight sub-stances, however, most excessive Cr was bound to a low-molecular-weight substance. Cr content decreased more rapidly than Cu and Pb content in the soluble fraction. Metal concentrations recovered in the liver lysosomes and excreted in bile were in the following order : Ca, Mn>Zn, Cu>Cr, Pb. These results suggest that biliary excretion of these metals, especially Mn and Ca, is primarily dependent on lysosomal metal uptake and release, and that the nature of metal binding substances for Cu, Pb, Cr and. Zn affects their transport systems in liver.
关键词：Metal transport;Liver:Lysosomes;Biliary excretion;Mu and Ca interaction;Metal binding substances
