DETERMINATION OF CHOLINE IN ERYTHROCYTES USING HIGH-RESOLUTION PROTON NUCLEAR MAGNETIC-RESONANCE SPECTROSCOPY - COMPARISON WITH A CHOLINE OXIDASE METHOD

Detailed operating conditions are reported for the determination of choline in human erythrocytes using proton NMR spectroscopy in conjunction with the inversion-recovery spin-echo pulse sequence. The results of NMR method were in excellent agreement with those obtained using an enzymatic (choline oxidase) assay; however, they were .apprx. 3 times higher than those reported using gas chromatography/mass spectrometry techniques. The differences may be partly due to the method of preparing or sampling cells since there is a distribution of choline in cells of different ages. Choline levels were not affected by the methods used for storing or preparing cells.