COMPARISON BETWEEN FISH LETHALITY DATA AND THE IN-VITRO CYTOTOXICITY OF LIPOPHILIC SOLVENTS TO CULTURED FISH CELLS IN A 2-COMPARTMENT MODEL

Cytotoxicity testing of non-hydrosoluble chemicals offers a major problem because cells are always cultured in aqueous media. An adaptation of the two-compartment model of Boue-Grabot et al. (1992) is reported here. The cytotoxicity of 19 lipophilic solvents was measured on cultured FHM (fathead minnow fish) cells. The FHM cells were seeded in transwells on a 0.4 mum pore membrane (upper compartment) which are placed in the wells of a 24 well culture plate (lower compartment). The transwells were then placed in wells containing the test chemical, solubilized in paraffin. After 24h the total protein content was measured. The relative toxicity is expressed by the EC50. This is the concentration of test chemical in the lower compartment required to induce a 50% inhibition of the total protein content in the upper compartment. No linear correlation was obtained between the EC50 of the lipophilic solvents and the in vivo fish lethality data obtained in golden orfe by Juhnke and Ludemann (1978). Nevertheless, this method allows the ranking of quantitative cytotoxicity data of lipophilic chemicals towards cultured-fish cells.