FIGURE 7.

Fractional rate of plasma PC synthesis by the PEMT pathway. (A) The enrichment of hepatic SAMe was determined by MIDA calculation based on the relative incorporations of the methyl-D₃ and methyl-D₆ labels into PC (mean ± SEM, n = 27). (B) Rate of fractional synthesis by the PEMT pathway after correcting enrichment of methyl-D₃-PC for enrichment of SAMe at each time point (% total PC). MIDA, mass isotopomer distribution analysis; PC, phosphatidylcholine; PEMT, phosphatidylethanolamine N-methyltransferase; SAMe, S-adenosylmethionine.