Quantitation of phosphatidyl N-methyl-and N,N-dimethylaminoethanol in rat liver

The contents of phosphatidyl N-methyl- and N,N-dimethylaminoethanol were determined in the liver of rats injected with (Me-C14) methionine. Total phospholipids were extracted from aliquots of the liver and fractionated by two-dimensional thin layer chromatography after addition of carrier phosphatidyl-N-methyl- and N,N-dimethylaminoethanol. The radioactivity present in the two phosphatide spots was determined and used to calculate total disintegrations per min/100 g body wt. The remainder of the livers was pooled, and total phospholipids were isolated and subjected to acid hydrolysis. N-methyl- and N,N-dimethylaminoethanol were purified by thin layer chromatography, and their specific activity was determined after quantitation by gas liquid chromatography and radioactivity measurement. The liver contents of phosphatidyl N-methyl- and N,N-dimethylaminoethanol were determined by dividing disintegrations per min/100 g body wt by the specific activity of N-methyl- or N,N-dimethylaminoethanol.