Hepatocytes in primary culture: an alternative to LD50 testing? Validation of a predictive model by multivariate analysis

By Peloux, A.F. - Federici, C. - Bichet, N. - Gouy, D. - Cano, J.P.

The cytotoxicity of 30 chemicals was assessed in rat hepatocyte primary cultures using four methods: lactate dehydrogenase release, neutral red uptake, the MTT assay, and measurement of total protein content. Comparison of the data obtained in vitro (IC50 values) and in vivo (LD50 values) resulted in a significant correlation (p < 0.001) between IC50 values and intravenous LD50 values. The validity, as well as the predictability of the model, were determined by multivariate analysis (principal component analysis and correspondence analysis). The predictability area, expressed in IC50 values, was in the range of 0-1,500 micrograms/ml and reached 95%, with a 75-100% confidence interval (p = 0.05). Assessment of the cytotoxicity of 54 additional chemicals would provide a more accurate predictability limit around 1,500 micrograms/ml and the estimated predictability confidence interval could be reduced to 90-100%.