The influence of biliary constituents in an acid medium on the micellar solubilization of unesterified fatty acids of the duodenal digesta of sheep

Abstract

1. Duodenal contents were collected from cannulated sheep that were fed on dried grass cubes. After high-speed centrifugation, the distribution of long-chain unesterified fatty acids between the aqueous and particulate fractions of the digesta was examined.2. The unesterified fatty acids of the digesta were found to be predominantly associated with the particulate matter.3. When gall-bladder bile was added to the digesta at 37° and pH 4.0, in vitro, it was observed that unesterified fatty acids were transferred from the particulate matter to micellar solution. This transfer was due largely to the solubilizing effect of bile salts acting together with biliary phospholipids.4. These findings are discussed in relation to the absorption of unesterified fatty acids by the sheep.