Dihomogammalinolenic acid (20:3 omega 6) is more anti-aggregatory than eicosapentaenoic (20:5 omega 3) in a platelet-endothelial cell mixture.

The effect of 20:3 omega 6, the precursor of 1 series prostaglandins was to inhibit platelet aggregation more strongly than either 20:5 omega 3, the precursor of 3 series prostaglandins or 20:3 omega 3 which is not a substrate of prostaglandin synthetase. When platelets and dissociated endothelial cells were pretreated with 20:3 omega 6, platelet aggregation in the presence of endothelial cells was much more inhibited than after 20:5 omega 3 pretreatment.