Identification and characterization of plasmalogen fatty acids in swine heart

Reperfusion of ischemic swine myocardium is associated with the loss of sarcolemmal phospholipids resulting in the accumulation of amphiphilic metabolites, lysophosphoglycerides and free fatty acids, especially arachidonic acid, causing electro-physiological dysfunction and cell death. Recently, phospholipids containing a vinyl ether bond at the Sn-1 position, commonly known as plasmalogens, have been identified as major constituents of heart, which contain a large amount of arachidonic acid in the Sn-2 position. Because of the potential importance of plasmalogens, the fatty acid composition of the choline and ethanolamine phosphoglycerides in swine heart was determined. Lipids were extracted from the left ventricular biopsies from swine heart, phosphoglycerides were separated from the neutral lipids by thin layer chromatography, converted into methyl derivatives and analysed by GC. The peaks for fatty acid methyl ester (FAME) and dimethylacetal (DMA) derivatives of choline and ethanolamine phosphoglycerides were confirmed using GC-MS. The results showed high amounts of 18:1 (17 mol%), 18:2 (24 mol %) FAME in choline phosphoglycerides in contrast to the occurrence of a high amount of 20:4 (28 mol%) FAME in ethanolamine phosphoglycerides, suggesting that plasmenylethanolamine, and not plasmenylcholine, may serve as the depot for arachidonic acid in swine heart.