Transfer of locally synthesized cholesterol from intestinal wall to intestinal lymph.

The cholesterol-fed rat subjected to cannulation of the intestinal lymph duct and injected with acetate-2-(14)C has been utilized for a study of the mechanism by which cholesterol synthesized in the intestinal wall gains access to the circulation. It has been concluded that locally synthesized cholesterol is excreted bidirectionally, approximately half going into the lymph and half into the lumen. Furthermore, under the conditions of these experiments, little of the luminal cholesterol appears to be reabsorbed, which suggests that direct transfer from wall to lymph is the principal route for the entry of this endogenously derived cholesterol pool into the lymph and ultimately into the blood stream. Finally, it has been demonstrated that bile is required for this transfer of cholesterol from wall to lymph as well as for the absorption of dietary cholesterol.