Regular article :AATEX 2(1):33-36
Within the framework of the MEIC (the Multicenter Evaluation of In Vitro Cytotoxicity) programme the long-term cytotoxicity of the MEIC chemicals 21-50 was investigated on MRC-5 cells. After 6 weeks treatment the PI50 was measured, which is the concentration (mM) of test compound required to induce at 50% reduction in total cell protein content. The results were compared with the acute PI50, measured after 24 hours in Hep G2 cells. The long-term PI50, values are lower than the acute ones. Warfarin was ten times less toxic in the long-term experiments. For the whole series of chemicals a good correlation between the two sets of data was observed (r=0.96), with the exception of digoxin and warfarin. As with other preliminary MEIC validation results, this study indicates that a good alternative cytotoxicity test may be found for the prediction human long-term toxicity.
Key words: MEIC, MRC-5 cells, long-term cytotoxicity.