PHOSPHATIDYLETHANOLAMINE SYNTHESIS IN THE NORMAL AND LYMPHOMATOUS MOUSE-LIVER - A C-13 NMR-STUDY

The lymphomatous liver contains high levels of phosphoethanolamine. Th is compound is a percursor of the phospholipid, phosphatidylethanolami ne. The kinetics of phosphatidylethanolamine synthesis has been studie d by C-13 NMR spectroscopy of extracts of the lymphomatous mouse liver following the administration of (C-13(2))ethanolamine. The concentrat ions of (C-13(2))ethanolamine, (C-13(2))phosphoethanolamine, and (C-13 (2))phosphatidylethanolamine were fitted to kinetic models and the max imal activities of the enzymes in the synthetic pathway were estimated . Phosphatidylethanolamine synthesis in the normal liver appears to be limited by the supply of ethanolamine. In the lymphomatous liver, bot h ethanolamine kinase and PE:CTP cytidylyltransferase had lower activi ties than in the normal liver, and there was evidence for a higher act ivity of ethanolamine base-exchange enzyme.