The effect of synthetic diether phospholipid on lipid absorption in the rat

The effect of synthetic diether phosphatidylcholine on lipid absorption in the rat was studied to determine whether this material inhibited absorption of either cholesterol or fatty acid. A lipid emulsion was prepared with sodium taurocholate, phospholipid, 3H-cholesterol, 14C-triolein, and oleic acid. Emulsion given to controls contained pig liver phosphatidylcholine as the source of phospholipid. For experimentals it was supplied as diether phosphatidylcholine. Emulsions were given by gavage into the stomach and recoveries of radioactive lipids in various regions of the gastrointestinal tract were determined with radioactive techniques 4 and 24 hours after receipt of the lipid challenge. Significantly greater amounts of 3H-cholesterol were recovered unabsorbed from the gastrointestinal tract of experimental rats at both 4 and 24 hours after administration of labeled lipids. Somewhat more of the 14C-oleic acid label derived from labeled triolein was also recovered unabsorbed in experimentals, although a significant difference was not observed between experimentals and controls. It is concluded that nondigestible (diether) phosphatadidylcholine inhibits absorption of cholesterol. This phospholipid, however, had no appreciable affect on fatty acid absorption as definitive malabsorption of this material was not observed under the conditions of this study.