Figure 5. LCA exhibits age-dependent differential effects on the concentrations (calculated as nmoles of glycerophospholipid/mg of protein) of different species of mitochondrial membrane glycerophospholipids. Cells were cultured in the nutrient-rich YP medium initially containing 0.2% glucose with 50 μM LCA or without it, in the presence of 1% DMSO (A, C and E) or in its absence (B, D and F). Mitochondria were purified from cells recovered on day 2, 4 or 7 of cell culturing. Protein concentration measurement in samples of purified mitochondria, extraction of mitochondrial membrane lipids, and mass spectrometric identification and quantitation of the extracted glycerophospholipid species were carried out as described in Methods. Based on these data, the concentrations of different molecular forms of mitochondrial membrane glycerophospholipids were calculated as nmoles of glycerophospholipid/mg of protein for mitochondria that were purified from cells recovered on day 2, 4 or 7 of cell culturing. Data are presented as means ± SEM (n = 3; *p < 0.01; ns, not significant).