Quantitation of phosphatidyl N-methyl and N,N-dimethyl aminoethanol in liver and lung of N-methylaminoethanol fed rats

Abstract

A diet supplemented with N-methylaminoethanol was fed to rats, and liver and lung phospholipids were resolved by a two dimensional thin layere chromatographic method affording the separation of phosphatidyl N-methylaminoethanol and phosphatidyl N,N-dimethylaminoethanol, as well as of the major phosphatides. Significant amounts of phosphatidyl N-methylaminoethanol and phosphatidyl N,N-dimethylaminoethanol accumulated within 24 hr in liver and lung. The fatty acid composition of liver phosphatidyl N-methylaminoethanol and phosphatidyl N,N-dimethylaminoethanol was determined. Stearic, arachidonic, and docosahexaenoic acids were the predominant fatty acids of these phosphatides. After injection of (Me-¹⁴C)methionine, only phosphatidyl N,N-dimethylaminoethanol and phosphatidylcholine became heavily labeled in both liver and lung. These findings indicate that N-methylaminoethanol is incorporated into phosphatidyl N-methylaminoethanol, and the latter is methylated to phosphatidyl N,N-dimethylaminoethanol and phosphatidylcholine.