MENINGIOMA PHOSPHOLIPID PROFILES MEASURED BY P-31 NUCLEAR-MAGNETIC-RESONANCE SPECTROSCOPY

Fourteen cases of intracranial meningioma were characterized after chl oroform/methanol extraction by P-31 nuclear magnetic resonance (NMR) s pectroscopy at 202.4 MHz. Each phospholipid class detected in the extr acts was identified and quantitated in terms of its molar percentage r elative to the total phospholipids measured. The following phospholipi ds were assayed by P-31 NMR: phosphatidylglycerol, phosphatidic acid, diphosphatidylglycerol, ethanolamine plasmalogen, phosphatidylethanola mine (PE), lysophosphatidylinositol, phosphatidylserine, sphingomyelin , lysophosphatidylcholine (LPC), phosphatidylinositol (PI), sphingosyl phosphorylcholine and phosphatidylcholine. In addition, two unidentifi ed phospholipids were detected with resonances at 0.13 and -0.78 ppm, respectively. Three distinct types of spectra were obtained on the ext racts and grouped accordingly for comparison purposes. Type 1 tumors s howed unusual P-31 NMR profiles with low levels of PE and PI and eleva ted levels of LPC; type 2 tumors were characterized by low levels of t he ethanolamine phospholipids and near equivalent levels of PI and LPC . The spectra of type 1 and type 2 tumors were characteristic of degen erative cells that lacked membrane permeability associated with loss o f ethanolamine plasmalogen in the presence of significant phospholipid turnover. Meningiomas belonging to the third spectral type showed cha racteristics similar to those of normal tissues with normal levels of PE and ethanolamine plasmalogen, as well as very low levels of LPC rel ative to PI. Type 3 tumors lacked the characteristic signs of degenera tion noted in type 1 and type 2 tumors. The data corroborate and augme nt in vivo spectroscopic findings reported earlier and demonstrate the value of P-31 NMR spectroscopic phospholipid analysis on Lipid extrac ts for the characterization of meningiomas.