Bile acid synthesis from newly synthesized vs. preformed cholesterol precursor pools in the rat.

The present study defines the origin of cholesterol subserving bile acid synthesis in male rats with an extracorporal bile duct by labeling newly formed cholesterol with tritiated water. Within 6 hr after interruption of the enterohepatic circulation, the bile acid pool was depleted. At this early time point the proportion from de novo cholesterol was 8% and 12% for biliary cholesterol and cholate, but 18% and 19% for muricholate and chenodeoxycholate, respectively.