Administration of phosphatidylcholine-cholesterol liposomes partially reconstitutes fat absorption in chronically bile-diverted rats

Background and aims: Intestinal bile deficiency in cholestatic patients leads to fat malabsorption. We addressed the potency of model bile, bile salts and phosphatidylcholine (PC)-cholesterol (CH) liposomes to reconstitute fat absorption in permanently bile-diverted (BD) rats. Methods: The plasma appearance of C-13-labeled palmitic acid (C-13-16:0) and linoleic acid (C-13-18:2) was determined after their enteral administration to BD or to control rats with an intact enterohepatic circulation (EHC) (C-13-16:0 and C-13-18:2 dissolved in 25% olive oil-75% medium chain triacylglycerol oil mixture). BD rats were intraduodenally infused with buffer, model bile [consisting of 60 mM taurocholate (TC), 8 mM PC and 1 mM CH], buffer with TC, buffer with PC and CH liposomes, or buffer with lyso-PC and CH. Results: Plasma concentrations of C-13-16:0 and C-13-18:2 were consistently three- to eightfold higher in control rats than those in buffer-infused BD rats (P <0.01). ID administration of either model bile or TC to BD rats restored plasma appearance of C-13-fatty acids at least to concentrations observed in control rats. Administration of PC+CH liposomes to BD rats partially reconstituted the plasma appearance of C-13-16:0, but did not affect that of C-13-18:2. Compared with control rats, the area under the curve (AUC) of plasma C-13-16:0 concentrations was 13.0 &PLUSMN; 6.9% in buffer-infused rats and 40.9 &PLUSMN; 3.1% in liposome-infused rats (P <0.005). Conclusions: Enteral administration of PC+CH liposomes to BD rats partially corrects the absorption of palmitic acid. Present data suggest that administration of PC+CH liposomes could enhance fat absorption in clinical conditions of cholestasis in which bile salt supplemention is contraindicated. (C) 2004 Elsevier B.V. All rights reserved.