Effect of some saturated and unsaturated fatty acids on in vitro platelet utilization of arachidonic acid

The effect of some saturated and unsaturated fatty acids pre-incubated with human washed platelets was examined on the platelet utilization of (1-14C) arachidonic acid. The platelets were incubated with the radioactive arachidonic acid for periods of either 10 min or 30 sec. The following results were obtained. Conversion of arachidonic acid to thromboxane B2 was increased during 10 min in the presence of oleic, alpha-linolenic and lauric acids. Increased conversion of 14C-arachidonic acid to hydroxy fatty acids (HHT and HETE) was observed in the presence of stearic acid (10 min incubation) and lauric acid (30 sec incubation). Their synthesis, however, was decreased in presence of gamma-linolenic acid (10 min incubation). Endoperoxide generation from arachidonate was reduced by alpha-linolenic acid but increased by stearic acid. The conversion to PGE2 was not altered by these acids during 10 min incubation with arachidonic acid. However, in presence of gamma-linolenic, lauric and stearic acids conversion of arachidonic acid into PGE2 during 30 sec incubation was increased. Under these conditions, production of PGF2 alpha and PGD2 remained unchanged.