FIGURE 6.
Impact of Cyp4f14 disruption on whole-body TOH metabolism and on concentrations of γ-TOH in plasma and tissues. A, metabolites of γ-TOH in 24-h urine and fecal collections from wild-type mice (solid bar) and Cyp4f14−/− mice (open bar) were quantified by GC-MS. Asterisks indicate significant differences from wild-type mice. B, change (nanomoles) from wild-type mice to Cyp4f14−/− mice in 24-h urinary and fecal excretion of metabolites of γ-TOH (solid bar) and δ-TOH (hatched bar) or the parent tocopherols. Cyp4f14−/− mice counterbalance the loss of ω-oxidation capacity by increased fecal excretion of 11′-OH- and 12′-OH metabolites and parent tocopherols. C, concentration of γ-TOH in plasma and tissues of wild-type (solid bar) and Cyp4f14−/− mice (open bar) fed the γT-165 (soybean oil) diet for 6 weeks. Inset compares tocopherol composition of liver of wild-type and Cyp4f14-null mice. Asterisks indicate significant differences from wild-type mice (p < 0.05).