[Transbilayer distribution of alpha-tocopherol and lipid asymmetry in nerve tissue membranes]

The alpha-tocopherol content and fatty acid composition of lipids in various types of nervous tissue membranes were studied. The transbilayer distribution of alpha-tocopherol and polyunsaturated fatty acids in liposomes and plasma membranes of synaptosomes was examined. It was shown that both phosphatidylethanolamine and phosphatidylserine are localized predominantly in the inner monolayer and they contain the bulk of polyenoic fatty acid residues. alpha-Tocopherol incorporated into liposomes from synaptosome plasma membrane lipids and present in synaptosome plasma membranes is also predominantly localized in the inner monolayers. No asymmetrical distribution of incorporated alpha-tocopherol was observed in liposomes prepared from a single phospholipid, e.g., dioleoylphosphatidylcholine.