Investigations into the relationship between phospholipids and brain acetylcholine

The effect of a phospholipid mixture extracted from the bovine cerebral cortex and of pure phosphatidylserine (PS), phosphatidylethanolamine (PE) and phosphatidylcholine (PC) on ACh output from the cerebral cortex was investigated in rats anaesthetized with urethane. All the phospholipids were administered after sonication. ACh was determined by bioassay. The following results were obtained: after i.p. administration of 100 mg/kg of the phospholipid mixture a marked increase in ACh output I asting approximately 30 min was observed. The i.v. administration of PS caused a dose-dependent increase in ACh. At the dose of 150 mg/kg a 3-fold increase over the spontaneous ACh output was found. PE was less active than PS and PC showed no effect on ACh output. The possibility that PS and PE might increase ACh output through a mechanism facilitating Ca penetration is discussed.