Stereospecific analysis of phospholipid classes in rat muscle

Abstract

The fatty acid and dimethyl acetal (DMA) compositions of the sn-1 and the sn-2 positions from individual phospholipid (PL) classes [phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylinositol (PI)], obtained from the Longissimus dorsi muscle of rat were studied. The profile of fatty acids and DMA in the sn-1 and sn-2 positions of all the PL classes showed marked differences. Overall, saturated fatty acids and monounsaturated fatty acids were in a higher proportion in the sn-1 position than in the sn-2 one, while polyunsaturated fatty acids were mainly in the sn-2 position. Significant differences in the DMA and fatty acid compositions between individual PL classes for each position were found. PC contained the highest proportion of palmitic acid (16:0) in the sn-1 position and of linoleic acid (18:2 n-6) in the sn-2 one. The highest values for stearic acid (18:0) and DMA in the sn-1 position and for docosahexaenoic acid (22:6 n-3) in the sn-2 position were found in PE. PS and PI showed the highest proportion of oleic acid (18:1 n-9) in the sn-1 position and of arachidonic acid (20:4 n-6) in the sn-2 position.