An in vitro binucleated blocked hepatic cell technique for genotoxicity testing in fish.

The main objective of this work was to develop and use a binucleated method which depends on the cytokinesis blocking of hepatic cells in fish to enable the scoring of micronuclei in cells that have completed only one division after genotoxic insult. The use of this novel technique in a study of the influence of some pollutants in vitro (selenium, mercury, methylmercury, and their mixtures) allows evaluation of the risk from exposure to these water pollutants under field and laboratory conditions. The frequencies of micronuclei in trout hepatic cells in vitro were elevated in a dose-dependent manner when compared to the relevant controls. Addition of Se(IV) reduced the frequencies of micronuclei in treatments with both forms of mercury. Inorganic mercury was found to be partly methylated when exposed to trout liver cells in vitro. The potential contribution of the fish binucleated hepatic technique to the toxicity assessment of the chemicals investigated is discussed.