Ether Phospholipids in Guinea Pig Polymorphonuclear Leukocytes and Macrophages. Occurrence of High Levels of 1-O-alkyl-2-acyl-sn-glycero-3-phosphocholine

Significant proportions of the choline phosphoglycerides (CPG) were found to contain alkyl either-type moieties (e.g., 1-O-alkyl-2-acyl-glycero-3-phosphocholine) in both guinea pig peritoneal exudate polymorphonuclear leukocytes (16.4%) and macrophages (13.5%). High proportions of the ethanolamine phosphoglycerides (EPG) contained alkenyl either moieties in both cells (37.2 and 41.2%), while the proportions of the CPG containing alkenyl moieties and of the EPG containing alkyl moieties were shown to be small. The either phospholipid composition as well as the fatty chain profiles of these two types of cells had relatively similar patterns. However, the fatty chains at the 1- and 2-positions for alkenyl either, alkyl ether and diacyl phosphoglycerides showed considerable differences. The amount of 16:0 at the 1-position was higher in alkyl compounds than that in diacyl compounds of the CPG. This was also the case in either-containing and diacyl EPG. The most predominant fatty acids at the 2-position was 18:2, in each lipid class, except for the alkenyl CPG. The amounts of 20:4 and other polyunsaturated fatty acids were low in every lipid class, though ether compounds contained higher amounts of 20:4 than diacyl compounds, particularly for EPG.