Hydrostatic Pressure Induces Apoptosis in the Human Leukaemic T‐Cell Line Jurkat Via the Mitochondrial Pathway

We investigated the effect of pressure levels ranging from 80 to 500 bar on the proliferative capacity and viability of Jurkat leukaemic T cells. Pressurization at 360 bar induced apoptotic cell death as shown by apoptotic morphology after Hoechst staining, DNA fragmentation in the TdT‐mediated dUTP nick end labelling‐assay and cleavage of several caspase substrates. Cell death could be prevented by the general caspase inhibitor zVAD‐fmk. Breakdown of the mitochondrial membrane potential and the release of cytochrome c provided strong evidence for an involvement of the mitochondrial pathway, whereas a central role of the death receptor pathway was excluded because caspase‐8 was not significantly activated. Pressure incubation led to calcium influx after 5 min, and we hypothesize that calcium influx could be the primary trigger for pressure‐induced apoptosis.