Hepatic phosphatidylethanolamine methyltransferase activity is decreased by ethanol and increased by phosphatidylcholine

Alcohol Clin Exp Res. 1994 Jun;18(3):592-5. doi: 10.1111/j.1530-0277.1994.tb00915.x.


Phosphatidylethanolamine N-methyltransferase participates in the synthesis of membrane phosphatidylcholine. Its activity was reported to be decreased in patients with alcoholic cirrhosis, but it is not known whether this is a consequence of the cirrhosis or precedes it. This question was studied in a baboon model of alcohol-induced fibrosis. Phosphatidylethanolamine N-methyltransferase activity was measured in sequential percutaneous needle liver biopsies by the conversion of phosphatidylethanolamine to phosphatidylcholine, using radioactive S-adenosylmethionine as a methyl donor. Chronic alcohol consumption (1-6 years) significantly decreased hepatic phospholipid and phosphatidylcholine levels and reduced phosphatidyl-ethanolamine N-methyltransferase activity even before the development of fibrosis. These effects were prevented or attenuated by supplementing the diet with 2.8 g/1000 kcal of a preparation rich in dilinoleoyl phosphatidylcholine, a highly bioavailable phosphatidylcholine species. There were significant (p < 0.001) correlations between phosphatidylethanolamine N-methyltransferase activity and both hepatic phosphatidylcholine (r = 0.678) and total phospholipid (r = 0.662).

Conclusions: 1. Alcohol consumption diminishes phosphatidylethanolamine N-methyltransferase activity prior to the development of cirrhosis and decreases the hepatic content of its product, namely phosphatidylcholine, a key component of cell membranes. This may promote hepatic injury and possibly trigger fibrosis. 2. Phosphatidylcholine administration ameliorates the ethanol-induced decrease in phosphatidylethanolamine N-methyltransferase activity and corrects phospholipid and phosphatidylcholine depletions, thereby possibly contributing to the protection against alcoholic liver injury.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Biopsy
  • Ethanol / toxicity*
  • Female
  • Liver / enzymology*
  • Liver / pathology
  • Liver Cirrhosis, Alcoholic / enzymology*
  • Liver Cirrhosis, Alcoholic / pathology
  • Male
  • Membrane Lipids / metabolism
  • Methyltransferases / antagonists & inhibitors
  • Methyltransferases / metabolism*
  • Papio
  • Phosphatidylcholines / metabolism
  • Phosphatidylcholines / pharmacology*
  • Phosphatidylethanolamine N-Methyltransferase
  • Phospholipids / metabolism


  • Membrane Lipids
  • Phosphatidylcholines
  • Phospholipids
  • Ethanol
  • Methyltransferases
  • Phosphatidylethanolamine N-Methyltransferase