Sex differences in platelet thromboxane and arterial prostacyclin production in control and n-6 fatty acid supplemented rats.

Sex differences in eicosanoid production in platelets and vessel walls have been studied in control and n-6 fatty acid supplemented rats. In platelet rich plasma (PRP) of control female rats, arachidonic acid (AA) levels in phospholipids (PL), thromboxane B2 (TxB2) formation following collagen stimulation and aggregatory responses to collagen were higher than in PRP of male rats. 6 keto PGF1 alpha release from PRP-perfused isolated aortas were the same for both sexes, but the antiaggregatory activity of the wall was higher in males than in females, in association with a greater sensitivity of male platelets to prostacyclin. The administration of n-6 fatty acid supplements increased AA level in PL, TxB2 production and aggregation only in male platelets. Production of 6 keto PGF1 alpha and the antiaggregatory activity of aortic walls were reduced after dietary treatment in males, but biochemical and functional parameters were not correlated in females. The results indicate complex sex-related differences in fatty acid metabolism and eicosanoid production, and in responses to n-6 dietary fatty acids in platelets and the vascular system in the rat.