The effect of albumin bound polyunsaturated fatty acids on human platelets.

Platelet rich plasma (PRP) was incubated at 22-24 degrees C for 24 hr with various polyunsaturated fatty acids (PUFA), bound to albumin, to determine whether changes in the FA composition of the platelet phospholipids might induce changes in platelet behavior and in platelet structural integrity. The PUFA tested were linoleic (18:2 w6), linoleic (18:3 w3), dihomo-gamma linolenic (20:3 w6), arachidonic (20:4 w6) and eicosapentaenoic acids (20:5 w3). Only PRP incubated with 20:3 w6 and 20:5 w3 incorporated significant amounts of these FA into the platelet phospholipids and showed inhibition of aggregation and TxB2 production with collagen. However, the inhibition was not due to the incorporation of these FA's into the phospholipids as observed by washing and resuspension of the FA incorporated platelets in control plasma, or to any change in structural integrity. It is suggested that the effect of 20:3 w6 and 20:5 w3 on aggregation is due to metabolites of these FA's released from the platelets.