Comparison of the generation of albumin-associated cytotoxic activity in supernatants from ethanol-containing cultures of human blood monocyte-derived macrophages and of two human hepatoma cell lines.
The rates of oxidation of ethanol to acetate by human blood monocyte-derived macrophages and the two human hepatoma cell lines PLC/PRF/5 and Hep G2 were studied. The average rates obtained were, respectively, 621, 447 and 596 nmol/h/mg cellular protein. Cultures of these three cell types, containing known quantities of cellular protein per flask, were incubated with 0 or 2 mg ethanol/ml for 72 h and the culture supernatants subjected to affinity chromatography on blue sepharose CL-6B. Pure albumin fractions obtained in this way were adjusted to the same optical density and tested for cytotoxicity against A9 cells. The data showed that the albumin fractions obtained from ethanol-containing macrophage cultures were considerably more cytotoxic than those obtained from ethanol-containing cultures of PLC/PRF/5 and Hep G2 cells. It appeared that, for a given quantity of ethanol metabolised, considerably more acetaldehyde was released extracellularly by macrophages than by the two hepatoma cell lines and that this acetaldehyde bound to albumin to form cytotoxic acetaldehyde-albumin complexes. The data raise the possibility that macrophages are an important source of extracellular acetaldehyde and circulating acetaldehyde-albumin complexes in vivo.
Wickramasinghe
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SN
Department of Haematology, St. Mary's Hospital Medical School, Imperial College of Science, Technology and Medicine, London, U.K.
Hasan
R
R
D000079:Acetaldehyde / Q000097:blood; D000428:Alcohol Drinking / Q000276:immunology*; D006528:Carcinoma, Hepatocellular; D002460:Cell Line; D003602:Cytotoxicity, Immunologic / Q000276:immunology*; D000431:Ethanol / Q000493:pharmacokinetics; D006801:Humans; D007728:Kupffer Cells / Q000276:immunology; D008113:Liver Neoplasms; D008264:Macrophages / Q000276:immunology*; D011485:Protein Binding / Q000502:physiology; D012709:Serum Albumin / Q000502:physiology*; D014407:Tumor Cells, Cultured / Q000276:immunology*
D012709:Serum Albumin; D000431:Ethanol; D000079:Acetaldehyde