title: Thymidine transport in hepatocytes. An assay for hepatotoxicity.
abstract: Thymidine transport and phosphorylation were investigated in isolated rat hepatocytes and AS 30 D hepatoma cells. In contrast to hepatoma cells, hepatocytes exhibited a minimum of thymidine phosphorylation due to a 100-fold smaller thymidine kinase activity. In hepatocytes thymidine is transported by two transport systems: a specific concentrative "high affinity" system and an unspecific non-concentrative "low affinity" system. In hepatoma cells only the "low affinity" system could be detected. A single dose of 20 or 50 mg diethylnitrosamine/kg body weight induced in hepatocytes a remakable increas of thymidine kinase activity and a decrease of the transport by the "high affinity" system. Thymidine transport and phosphorylation by hepatocytes are considered to be sensitive markers for early recognition of toxin-induced liver regeneration.
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002455:Cell Division; D056486:Chemical and Drug Induced Liver Injury / Q000378:metabolism*; D004052:Diethylnitrosamine / Q000494:pharmacology; D066298:In Vitro Techniques; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation; D051381:Rats; D013936:Thymidine / Q000378:metabolism*; D014118:Toxins, Biological / Q000494:pharmacology
chemical_list: D014118:Toxins, Biological; D004052:Diethylnitrosamine; D013936:Thymidine