Effect of chlorpromazine on intracellular transport of phospholipids

The transfer of phosphatidylinositol from rat liver microsomes to liposomes stimulated by cytoplasmic protein was found to be inhibited by the addition of chlorpromazine, while the phosphatidylcholine transfer was not affected. The administration of chlorpromazine has been shown to enhance the synthetic rate of phosphatidylinositol and is assumed from the present experiment to decrease the intracellular transfer rate, leading to the accumulation of phosphatidylinositol in the endoplasmic reticulum. On the other hand, chlorpromazine caused the depression of the secretion of phosphatidylcholine to the blood plasma. Thus, the phospholipid composition of rat liver endoplasmic reticulum seems to remain unchanged by the balance of the intracellular alterations of phospholipid metabolism.