Effects of dipalmitoylphosphatidylcholine liposomes on high affinity transport of choline and synthesis of acetylcholine in cerebral cortical synaptosomes in the rat.

The presynaptic cholinergic effects of the phospholipid dipalmitoylphosphatidylcholine were investigated in non-depolarized synaptosomes from the cerebral cortex of the rat. This naturally-occurring phospholipid, in the form of small unilamellar vesicles (3.0 mg/ml), inhibited both high affinity uptake of [3H] choline and the synthesis of [3H] acetylcholine. This lipid-induced inhibition was apparently competitive, since it was observed at 1 microM but not 20 microM extracellular concentration of choline. These results indicate that dipalmitoylphosphatidylcholine may reduce the synthesis of acetylcholine in resting nerve terminals.