Role of phospholipase A2 on the variations of the choline signal intensity observed by 1H magnetic resonance spectroscopy in brain diseases

Phospholipase Az catalyzes the hydrolysis of membrane glycerophospholipids leading to the production of metabolites observable by both H-1 and P-31 magnetic resonance spectroscopy. The signal of choline-containing compounds (Cho) observed by H-1 magnetic resonance spectroscopy is constituted of metabolites of phosphatidylcholine, especially phosphocholine (PCho) and glycerophosphocholine (GPCho). The phosphomonoester (PME) and phosphodiester (PDE) signals observed by P-31 magnetic resonance spectroscopy are, respectively, precursors and catabolites of phospholipids. A large number of brain diseases have been reported to cause variations in the intensity of the Cho, PME and PDE signals. Changes in the activity of phospholipase A(2) have been measured in many brain diseases. In this review, the relationships between the results of H-1 and P-31 magnetic resonance spectroscopy and the phospholipase A(2) assays are analyzed. In many brain diseases, the variation in the Cho signal intensity can be correlated with a stimulation or inhibition of the phospholipase A(2) activity. (C) 2000 Elsevier Science B.V. All rights reserved.