A significant contributor of plasma Hcy is
hepatic AdoHcy generated by the 3 methylation reactions catalyzed by
PEMT during the conversion of PE to PC. Thus, the plasma levels
of Hcy are 50% lower in Pemt−/− mice than in Pemt+/+ mice and
hepatocytes isolated from Pemt−/− mice secrete 50% less Hcy than do
Pemt+/+ hepatocytes [92].