The use of freshly isolated gill epithelial cells in toxicity testing

The large number of chemicals in our environment, many of which have been insufficiently tested for toxicity, justifies the need for rapid and reliable in vitro testing to predict toxicity. In aquatic toxicology the use of cellular toxicity tests has been limited. In the present study, the usefulness of freshly isolated gill epithelial cells from rainbow trout in toxicity testing was evaluated by testing the cytotoxicity of 30 reference chemicals to the cells using the fluorescent cell viability probe Calcein-AM. The results were compared with previously obtained EC(50) values for the chemicals in freshly isolated rainbow trout hepatocytes, EC(50) values for immobilization of Daphnia magna and literature data on LC(50) values for fish. Regression analysis of the data obtained with gill epithelial cells and hepatocytes showed a correlation coefficient of 0.77 (r(2) = 0.59). The gill epithelial cells were slightly more sensitive than hepatocytes to the chemicals. The slope of the regression line was 0.79. Both cell types were less sensitive than D. magna and fish to the chemicals, but the EC(50) values for gill epithelial cells showed a better concordance with EC(50) values for immobilization in D. magna and with literature data for fish LC(50) values than the hepatocyte EC(50) values.