FIGURE 5.

Conversion of PK-d₇ to MK-4-d₇ in the rat small intestine epithelial cell line IEC-6. IEC-6 cells were cultured for 3 days at a density of 5 × 10⁶ cells/well in 6-well tissue culture plates in low glucose DMEM containing 10% FCS at 37 °C in 5% CO₂ in a humidified atmosphere. The cells were then incubated with PK-d₇ (1 μm) at 37 °C for 24 h. The cells were collected, and the lipids were extracted using 3 ml of hexane/diethyl ether (97:3). MK-4-d₇ and its epoxide were measured by APCI-LC-MS/MS as described under “Experimental Procedures.” N.D., not detected. Error bars represent S.E.