Intestinal Absorption of Micellar Lipid in Normal and Bile Deficient Rats 1

Abstract

Summary

The small intestines of control and bile fistula rats were perfused for 4 hr with a micellar solution of bile salt, glyceryl monooleate, and ¹⁴C-labeled oleic acid followed by rapid washout and steady perfusion with saline for an additional 4 hr. Measurements on hourly lymph collections from the thoracic duct for 8 hr, pooled ileal effluents and intestinal wall showed that (i) in both groups endogenous lymph lipid increased in proportion to the total lipid, (ii) in the control group lymph lipid increased after 3–6 hr to peak concentrations of from 15.1 to 38.8 mg/ml or 2.7-7.0 times that of the micellar solution, (iii) in both groups similar amounts of the micellar lipid were absorbed but the bile fistula group retained a significantly higher proportion in the wall after 8 hr and transported a significantly lower proportion in the lymph. The results support the micellar concept of lipid absorption by showing the production of chylomicrons from micelles in control animals but indicate that chylomicron production or transport is abnormal in bile fistula animals despite the presence of bile salts in the lumen above the critical micellar concentration.