Dietary alpha-linolenic acid suppresses the formation of lysophosphatidic acid, a lipid mediator, in rat platelets compared with linoleic acid

Rats fed a high linoleic acid (LA, 18:2n-6) diet or a high alpha-linolenic acid (ALA, 18:3n-3) diet for 4 months after weaning. Platelets from the high-LA group contained more arachidonic acid (AA, 20:4n-6) and less eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) compared with those from the high-ALA group. Incorporation of [(32)p]orthophosphate into platelet phospholipids was increased by thrombin-treatment, and was greater by ca. 30% in the high-LA group than in the high-ALA group both in the presence and absence of thrombin. The formation of [(32)p]lysophosphatidic acid (LPA), a lipid messenger, in [P-32]orthophosphate-labeled platelets was increased 6.6-fold in the high-LA group and 4.1-fold in the high-ALA-group by thrombin-treatment. The formation of [P-32] LPA in activated platelets was reduced by 35% in the high-ALA group. (C) 2003 Elsevier Inc. All rights reserved.