Mechanisms of lipid loss from the small intestinal mucosa.

Many water-soluble compounds have been shown to pass from the small intestinal mucosa into the lumen. In this work, the loss of lipids from the mucosa was investigated by perfusion experiments in rats, using 0-15M NaCl or buffer solutions over range of pH, with or without the addition of 5-7 or 11-4mM taurocholic acid. Perfusates were extracted for the estimation of individual lipids and for DNA, which is a measure of cell loss. The results suggest that free fatty acids reach the lumen by diffusion and that their solubility in the luminal fluid is a factor determining their rate of loss. Triglycerides, cholesterol, phosphatidyl ethanolamine, and phosphatidly choline are present onlyas the result of desquamation of mucosal cells.