Toxicity of paracetamol and cyclophosphamide in monolayer cultures of rat and human hepatocytes.
Hepatocyte structural and functional integrity was characterized in short-term primary monolayer cultures. Ethoxycoumarin-O-deethylase activity, cellular glutathione, ATP and ADP content, protein synthesis and lactate dehydrogenase (LDH) leakage were monitored. Cytotoxicity and perturbation of hepatocyte function involving measurement of these biochemical parameters was investigated following exposure to paracetamol and cyclophosphamide. Evaluation of several biochemical parameters appears to be a more appropriate assay of a perturbation in cellular integrity than the use of a single parameter. In the case of paracetamol the response of human hepatocyte cultures was broadly similar to that observed in rat hepatocyte cultures. An increase in LDH leakage occurred following exposure to high dose levels and was associated with depletion of cellular glutathione levels. At both toxic and non-toxic dose levels protein synthesis was impaired and a decrease in the cellular ATP/ADP ratio was evident. A decrease in protein synthesis and cellular glutathione was observed in both rat and human hepatocytes following exposure to cyclophosphamide. The data highlight the potential use of hepatocyte cultures for investigation of specific cytotoxic events and also emphasize the incorporation of human tissue in such systems.
Lawrence
J N
JN
Robens Institute of Health and Safety, University of Surrey, Guildford, Surrey GU2 5XH, UK.
Benford
D J
DJ