Abstract: | The lipid composition of synaptic vesicles isolated from adult rat brain was determined. Vesicles contained cholesterol and phospholipid but very little ganglioside, galactolipid, free fatty acid and triglyceride was detected. Ethanolamine and choline phosphoglycerides were the dominant phospholipids. Lysophosphatidyl choline was present in very low amounts. The fatty acid composition of the phosphoglycerides was characterized by high levels of docosahexaenoic acid in the ethanolamine and serine phosphoglycerides, and the absence of long chain fatty acids from the sphingomyelins. All the characteristic features of the lipid composition of the synaptosomal plasma membrane (with the exception of the ganglioside content) were seen in the synaptic vesicle lipids. The results are discussed in terms of the exocytosis mechanism of transmitter release. |