The Level of Phospoethanolamine and Phosphocholine in Intact Neuroblastoma Cells: Effects of Cell Differentiation and of Exogeneous Ethanolamine and Choline

Large concentrations of phosphoethanolamine (PEt) have been reported for mouse and human neuroblastoma, human glioblastoma, rat glioma and lymphoid cells. Because of this we decided to examine the conditions effecting the levels of PEt and phosphocholine (PCh) in the neuroblastoma cell line NIE-115, a modle cell systems for sympathetic neurons, a microcarrier based perfusion system capable of sustaining the cells in good physiological condition was used to make 31P NMR measurements. The cells were grown in tissue culture, induced to differentiated then put in the spectrometer. Spectra from these cells were compared to data obtained from undifferentiated cells. Spectra were also obtained on differentiated and undifferentiated cells which had ethanolamine (Et) added (final concentration 200 micron M). The PEt/ATP ratio was found to be 0.2 for the differentiated and 3.4 for the undifferentiated cells. The ratio of PEt/PCh for the cells was 0.5 for the undifferentiated and 0.67 for the differentiated cells. Nine hours after addition of Et the ratio of PEt/ATP went up 2.35 times for the differentiated cells while the undifferentiated cells went up only 1.55 times. These findings show that reserves of PEt are greater in differentiated NIE-115 cells and that these cells have some advantage in the differentiated state for taking up Et and phosphoralating it.