Effects of oral phosphatidylcholine on mouse brain choline and acetylcholine.

Oral phosphatidylcholine (PC) in a dose of 250 mg/kg choline equivalent, was given 1, 2, 4, 8, 12, and 24 hr prior to brain assay to groups of fasted mice. The animals were then killed by focused microwave irradiation to the head and brain choline (Ch) and acetylcholine (ACh) assayed by chemical demethylation using gas chromatography-nitrogen phosphorous (GC-NP) detection. Mouse brain Ch levels increased significantly at 4 (P less than .001) and 8 (P less than .01) hr after PC administration. However, there was no change in mouse brain ACh. When this experiment was repeated in a second series of animals at 1, 3, 6, and 12 hr pretreatment with PC, only the 6 hr pretreatment showed a significant increase in brain Ch (P less than .01). The effects of PC administration to alter the known ACh depleting effects of scopolamine were also determined by giving PC orally 4 hr before and scopolamine, 0.1, 0.32, and 1 mg/kg, one hr before microwave irradiation. The known depleting effects of scopolamine pretreatment on brain ACh were confirmed (P less than .001). A large dose (1 mg/kg) of scopolamine also caused a decrease in brain Ch (P less than .001). Pretreatment with PC reversed the depletion of brain Ch induced by scopolamine but had no effect on depleted brain ACh. The results indicate that, although mouse brain Ch can be increased by oral PC, there is no effect on mouse brain ACh.