In comparison with dietary high-
linoleate safflower oil, high alpha-
linolenate perilla oil decreased alkylacyl- and alkenylacyl-glycerophosphocholine (GPC) content in rat kidney by roughly 30 and 25%, respectively. The
fatty acid composition was also modified by high alpha-
linolenate oil;
arachidonic acid (AA) level in alkylacyl-GPC, a
platelet-activating factor (PAF) precursor, decreased by 30% along with concomitant increases in the
n-3 fatty acid levels. PAF contents under resting conditions were similarly low in the two dietary groups. Fifteen minutes after
endotoxin administration, PAF and
lyso-PAF contents increased significantly, and the PAF content in the high alpha-
linolenate group was 60% lower than in the high
linoleate group; the
lyso-PAF contents also tended to be lower.
Lyso-PAF acetyltransferase and CoA-independent transacylase activities in kidney microsomes increased significantly after
endotoxin administration, while
PAF acetylhydrolase activity in the cytosol was relatively unchanged. The
lyso-PAF acetyltransferase and
PAF acetylhydrolase activities did not differ between the two dietary groups, but the
CoA-independent transacylase activity was roughly 30% lower in the high alpha-
linolenate group. In agreement with in vitro study, our present study demonstrates that dietary high alpha-
linolenate suppresses PAF production in rat kidney during systemic
endotoxemia, and which is mainly due to the decrease in alkylacyl-GPC content, altered
fatty acid compositions of the precursor
lipids and lower
CoA-independent transacylase activity.