NMR spectroscopic analysis of rat brain development: In vitro proton and carbon studies of whole tissue and its phospholipid fraction

The developmental patterns of the rat brain at several postnatal time point s were investigated in Folch (chloroform-methanol) extracts. The chloroform -(lipid-containing) and water-soluble (cytosolic) fractions of whole-tissue extracts and the phospholipid fraction separated from the organic fraction by chromatography were analysed by means of high-resolution H-1 and C-13 n uclear magnetic resonance (NMR) spectroscopy. Analysis of the cytosolic fra ction showed the changing patterns of several brain metabolites during post natal maturation, in full agreement with data obtained from perchloric acid extracts. H-1 NMR spectroscopy of the phospholipid fraction allowed for qu antitative evaluation of fatty acid acyl chain length, mean unsaturation an d mean polyunsaturation. It was found that both mean unsaturation and polyu nsaturation are lower in adult brain phospholipids than during the first 3 postnatal weeks. C-13 NMR spectroscopy of the same fraction showed that the molar percentage Of C-18 fatty acids (oleic, linoleic, linolenic) in brain phospholipids is similar at all the investigated time points. These result s indicate that the combination of Folch extraction with simple chromatogra phic procedures and NMR analysis yields useful data to define the chemical maturation of the brain. Copyright (C) 2001 S. Karger AG, Basel.