Lack of effect of Bcl-xL over expression on ionomycin-mediated increase in Ca2+ levels.

a) Time-course of Ca2+ levels, expressed as percentage of maximum Ca2+ response, following ionomycin (2 µM; arrow) addition to SH-SY5Y/Neo (solid lines) and SH-SY5Y/Bcl-xL cells (dashed lines). Following an initial Ca2+ peak, a late Ca2+ increase occurs reaching a plateau that is taken as the maximum Ca2+ level for the neuron. b) Cytoplasmatic response to ionomycin treatment (2 µM) in SH-SY5Y/Neo (n = 10) and SH-SY5Y/Bcl-xL (n = 11) cells measured as the ratio of the early Ca2+ peak to the maximal ionomycin signal obtained during each individual experiment. Data represent mean ± S.E.M of the indicated number of experiments.