Fig. 5.

Quantification of PS, PI, and SM in skin fibroblasts. PS (A), PI (B), and SM (C) species were determined using LC-MS/MS with MRM scanning of the neutral loss of m/z 87 in negative mode, the precursor ion of m/z 241 in negative mode, and the precursor ion of m/z 184 in positive mode, respectively. Values were normalized against the amount of protein in the cells. Data are the mean ± SD from triple analyses in one experiment. Each experiment was repeated at least three times with similar results. *P < 0.05 as compared with control (Cont) cells.