Journal of Lipid Research, Vol 28, 326-331, Copyright © 1987 by Lipid Research, Inc.
Fatty acid composition of diacyl, alkylacyl, and alkenylacyl phospholipids of control and arachidonate-depleted rat polymorphonuclear leukocytes
CS Ramesha and WC Pickett
Phospholipid fatty acid composition and phospholipid subclass distribution
of control and arachidonate-depleted rat polymorphonuclear leukocytes (PMN)
were compared. The 20:4-depleted PMN contained significantly higher amounts
of 16:1, 18:1 and 20:3 (delta 5,8,11) and lower amounts of 18:2 and 20:4
than the phospholipids from control cells. Choline-containing
glycerophospholipids (CGP) were the major phospholipids of both control and
20:4-depleted cells representing 34% and 37% of the total phospholipids,
respectively. Significant amounts of ethanolamine-containing
glycerophospholipids (EGP) (29% and 30%) and sphingolipids (20% and 18%)
were also present in both cell types. Serine-containing
glycerophospholipids (SGP) together with inositol- containing
glycerophospholipids (IGP) constituted 16% and 13% of the phospholipids in
control and 20:4-depleted cells, respectively. CGP from control cells had
significantly higher amounts of 16:0 and 18:2 and lower amounts of 18:0 and
20:4 than EGP, whereas CGP from 20:4- depleted cells has higher amounts of
16:0 and 16:1 and lower amounts of 20:3 than EGP. Analysis of the subclass
composition of CGP and EGP revealed that both control and 20:4-depleted
cells contained significantly large amounts of alkylacyl-GPC and
alkenylacyl-GPE. Small amounts of alkylacyl-GPE and alkenylacyl-GPC were
also observed. The predominant fatty acyl residues found in the
1,2-diacyl-GPC, alkylacyl- GPC of control cells were 16:0, 18:0, 18:1,
18:2, and 20:4, while those of 20:4-depleted cells were 16:0, 16:1, 18:0,
18:1, and 20:3. More than 60% of CGP-bound 20:4 of control cells and about
70% of the CGP-bound 20:3 of 20:4-depleted cells were found in their
alkylacyl species.(ABSTRACT TRUNCATED AT 250 WORDS)