Figure 7.

Fatty acid composition of PtdIns, PtdInsP, PtdInsP₂, PtdEtn, PtdCho, and PtdOH. PtdOH was extracted after an exposure at 0°C for 10 min, whereas the others phospholipids were extracted from nontreated cells. Lipids were separated by TLC. PtdInsP and PtdInsP₂ spots were scrapped off plates developed in the alkaline solvent, and the other phospholipid spots were scrapped off plates developed by two-dimensional TLC. Fatty acids were transformed in methylesters before being separated by gas chromatography (see “Materials and Methods”). Data are the mean of five independent determinations. Fatty acids are 16:0 (black), 18:0 (white), 18:1 (hatched), 18:2 (light gray), and 18:3 (dark gray) molecular species.