Regulation of14C-cholesterol uptake from mixed micelles by organ culture of the mucosa epithelium from human small intestine: Effects of selective ACAT inhibitor

The initial rate of14C-cholesterol uptake from mixed micelles is studied using organ culture of mucosal epithelium from human small intestine obtained during surgery. Intense, reproducible, and ACAT-regulated level of specific14C-cholesterol uptake is monitored during the first 3 h of culturing. The specific14C-cholesterol uptake is assessed by the difference between the total uptake of14C-cholesterol and nonspecific uptake of14C-sitosterol from the micelles. It is shown that less than 20% of absorbed14C-cholesterol is converted into cholesterol esters. C44788, a high-affinity and selective ACAT inhibitor, inhibits14C-cholesterol uptake in a dose-dependent manner and practically has no effect on14C-oleate uptake.