The effect of diether phosphatidylcholine on the enterohepatic circulation of biliary sterols.

The effect of diether phosphatidylcholine on the enterohepatic circulation of bile salts and cholesterol was determined using the bile duct cannulated rat. Animals were infused intraduodenally with a solution containing radioactive bile salts and cholesterol. Phospholipid was also present in the infusate. In control animals it was supplied by pig liver phosphatidylcholine (diester). For experiments, equimolar amounts of diether phosphatidylcholine were used. No difference was observed between control and experimental groups for absorption and subsequent secretion of bile salts into bile. Significantly less cholesterol was absorbed, however, by experimental rats. This was correlated with a decreased secretion of radioactive cholesterol into bile. In controls, almost 14% of the administered dose of cholesterol appeared in bile over the period of infusion while the value for experimentals was 5%. It is concluded that diether phosphatidylcholine inhibits the enterohepatic circulation of cholesterol but not of bile salts.