As the PC/PE ratio declined, plasma
ALT increased.Moreover, PEwas detected in the outermonolayer of the
plasma membrane of liver cells fromPemt−/− mice after 2 days of choline
deficiency but not in Pemt−/−/Mdr2−/− mice. Thus, the liver failure
in Pemt−/− mice appears to be due to a loss of membrane integrity
caused by a decrease in the PC/PE ratio of the plasma membrane