Figure 1: Inhibition of the CDP-ethanolamine pathway by 25-hydroxycholesterol. Mouse cells C3H10T1/2 were treated with 10 ng/μL of 25-OH (filled triangles), “pulsed” with 14C-Etn for 1 hour and “chased” with an excess of unlabelled ethanolamine as indicated. 14C-ethanolamine (A), 14C-phosphoethanolamine (B), and 14C-CDP-ethanolamine (C) products were determined from the water phase and the radio-labeled PE (E) was quantified from the organic phase. Untreated cells grown in serum-free media (open squares) were used as controls. Data shown are from three independent experiments performed in duplicate; (*) indicates differences between treatments at P < .05.