Real-time monitoring of cadmium toxicity in rabbit kidney cells

The aim of this study was to investigate the toxic effect of the metal salt cadmium chloride dihydrate on the rabbit kidney cell line using the xCELLigence system or real-time cell analyser (RTCA), and to compare this relatively new method with standard biological cytotoxicity assays. This system provides real-time monitoring of cell behaviour and proliferative activity during the whole time of experiment. Moreover, after 24 h exposure of cells to cadmium, colorimetric 3-[4,5-dimethylthiazol-2-yl]-2,5-difenyl tetrazolium bromide (MTT) test was used to measure the metabolic activity and cytotoxicity was determined by measurement of lactate dehydrogenase (LDH) leaked from damaged cells. We found that renal cells exposed to lower concentrations (5–10 mg·l -1 ) of cadmium tend to grow similarly to control cells, however, cell index was significantly different ( P < 0.05) after 24 h. With increasing concentration of cadmium (15–50 mg·l -1 ) significantly lower proliferative ( P < 0.05) and metabolic activity (P < 0.05) of cells was observed and cytotoxicity increased simultaneously (P < 0.001). In addition, we found that the real-time monitoring of the cell response was significantly correlated with commonly used biological methods for toxicity measurement, for MTT assay R2 was 0.9448 (P < 0.01) and for LDH assay R 2 was 0.9466 (P < 0.01), respectively. The present study is the first report when combination of RTCA, MTT assay and LDH test was used for cadmium nephrotoxicity assessment. In all these methods, the toxic effect of cadmium on rabbit kidney cells increased in a concentration-dependent manner. xCELLigence system, nephrotoxicity, cytotoxicity, lactate dehydrogenase