CORRELATIONS BETWEEN THE RTG-2 CYTOTOXICITY TEST EC50 AND IN-VIVO LC50 RAINBOW-TROUT BIOASSAY

This paper presents data on the validation of the RTG-2 in vitro cytot oxicity test. Correlations between in vivo 96h LC50s on rainbow trout and in vitro EC50s obtained with this test, were established. The acut e cytotoxicity of 16 common aquatic pollutants were determined in vitr o on RTG-2 cells, an established fibroblastic-like cell line derived f rom rainbow trout, using three quantitative analyses, as toxicological endpoints, on the same cell microplate: intracellular ATP content; ce llular viability using neutral red assay (NR), and detachment of the g rown surface substratum using FRAME KB protein assay (KBP). The three values obtained, were also transformed by a cytotoxicity index (CI), i n a singular value of cytotoxicity. Dose-response curves were obtained . Good correlations between in vivo LC50s and in vitro EC50s for each endpoint and for the cytotoxicity index (CI) were found. Correlation c oefficients were 0.965, 0.968, 0.977 and 0.970 for ATP, NR, KBP and CI 50 respectively. Results indicate the applicability of the RTG-2 test as alternative protocol to estimate the acute toxicity of chemicals on fish without using live animals. The inclusion of this test instead o f standard toxicity tests on fish would provide a fully alternative sy stem, without testing on vertebrate animals, for the classification an d preliminary risk assessment of the environmental hazard of substance s. Copyright (C) 1996 Elsevier Science Ltd