Detection of apoptotic changes in HeLa cells after treatment with paracetamol and sodium fluoride

Apoptosis is genetically programmed cell death, an irreversible process of cell senescence with characteristic features (cell shrinkage, chromatin con densation. DNA fragmentation, apoptotic bodies) different from necrosis. Se veral effective in vitro methods for qualitative and quantitative detection of apoptotic events have been developed. Chromatin degradation, reductions in cell volume and other apoptosis-associated changes in cell morphology a nd physiology can be quickly analysed by multiparametric flow cytometry (FC ) using small numbers of intact cells. One further method used for morpholo gical determination of apoptotic changes is the fluorescent microscopic tec hnique (FM) based on labeling of cells with fluorochromes acridine orange a nd ethidium bromide. In our experiments FC was used for determination of DNA changes in HeLa cel ls based on staining of DNA by fluorochrome propidium iodide (PI). Among th e tested chemicals (paracetamol and sodium fluoride) apoptotic process coul d only be detected in paracetamol-treated cells. Apoptosis was induced main ly in cells treated with paracetamol (concentration range 4-5 mg/ml) for 8 h and following incubation for 18 h in fresh medium without paracetamol. Th e results obtained by the FM method correlated with the results obtained by FC.