Ceramide and adenosine analoga in the apoptotic path way of EL4-cells

The lipids and the fatty acid composition are important regulators of cellular function and the membrane fluidity. The fluorescence dye laurdan was chosen to determine membrane fluidity in terms of generalised polarisation (GP) values in isolated membranes and whole cells. At the early apoptotic stages no significant alterations of the GP could be detected indicating a regulation mechanism to maintain membrane integrity. The investigation of apoptotic EL4 cell lipid compositions, ceramide metabolism, and modulation of the fatty acid spectra indicate that these variations stand for an early apoptotic phase, and that the mode of action of the lipid messenger ceramide is, compared to tubercidine, not a direct effect of the DNA fragmentation in the pathway of programmed cell death