PHARMACOLOGICAL EFFECTS OF PHOSPHATIDYLSERINE LIPOSOMES: THE ROLE OF LYSOPHOSPHATIDYLSERINE

Abstract

1 Unique among the phospholipids, phosphatidylserine depresses brain energy metabolism when injected intravenously into mice in the form of sonicated liposomes. The possibility that this effect results from a metabolic transformation of phosphatidylserine is examined in this paper. 2 A strong enhancement of the phosphatidylserine effect is induced by the incubation of liposomes with rat serum. Similar phosphatidylserine activation is observed after the incubation of the phospholipid with purified phospholipase A₂ from pancreas. In both cases phosphatidylserine is split into the deacylated derivative, lysophosphatidylserine. 3 Lysophosphatidylserine reproduces with greater efficacy the effect of phosphatidylserine on brain energy metabolism. Other lysophospholipids are not effective. 4 It is concluded that the pharmacological effects of phosphatidylserine liposomes is due to the generation of lysophosphatidylserine.