EN
The aims of the study were determining the median cytotoxicity indicate (IC50), nature of cell death (apoptosis/ necrosis), assessment and morphology of changes observed in FAO cell line culture of hepatocytes subjected to ionophore antibiotics, salinomycin and lasalocid, incubations. INVTTOX recommended MTT, NRU and KB cytotoxicity tests were used to research mitochondrial, protein synthesis and cell proliferation. In addition cell staining in order to reveal membrane destruction that established cell death character May-Grunwald & Giemsa staining were also conducted. Cytotoxicity indices (IC50) estimated by the 24 hour MTT test were at a level 2.41 ± 0.29 mM and 7.93 ± 0.01 mM; however, after a 48 hour incubation the values lowered to 0.112739 ± 0.01 mM and 0.59 ± 0.01 mM for salinomycin and lasalocid, respectively. In contrast to the MTT data, that of NRU and KB tests were higher, indicating mitochondria as the main subcellular target for the antibiotic action. The determined IC50 values were positively related to DL50 (the data from references). Hepatocytes death were established to be of an apoptosis nature. Cell morphology was changed from IC50 depending on manner; the lower value of the indicate corresponded to more pronounced cytopathologic findings. Summarizing, monolayer cell cultures of rat hepatocytes proved to serve as a useful model for cytotoxicity studies enabling to indicate subcellular targets for ionophore antibiotics