DIFFERENCES IN THE MEASUREMENT OF CYTOTOXICITY OF COMPLEX-MIXTURES WITH RAINBOW-TROUT HEPATOCYTES AND FIBROBLASTS

The purpose of this study was to compare cytotoxicity tests for indust rial/municipal wastewaters using two different cell systems: rainbow t rout hepatocytes and gonadal fibroblasts. They were exposed to concent rations of industrial/municipal wastewaters for 48 h at 15 degrees C. In addition, wastewater toxicity was evaluated concurrently with the 9 6-h rainbow trout acute lethality bioassay. Hepatocyte viability was a ssayed with the propidium iodide (PI) exclusion and neutral red (NR) u ptake inhibition tests, while gonadal fibroblast viability was assayed with the NR uptake test. The results show that hepatocyte viability m easurement by the PI exclusion test and NR uptake are in agreement wit h complex mixture exposures. Moreover, cytotoxicity was correlated wit h trout mortality for most of the effluents (80%). Although a low corr elation was found between the trout fibroblast and the hepatocyte NR u ptake assays, the NR uptake assay using gonadal fibroblasts was correl ated with trout mortality, but in only 60% of the samples tested. Hepa tocyte cytotoxicity data, whether determined by the PI exclusion test or ale NR uptake test, appeared to be more strongly associated with tr out toxicity than did the rainbow trout gonadal fibroblasts, in the ca se of complex environmental mixtures. (C) 1998 Elsevier Science Ltd. A ll rights reserved.