Pancreatic lipase/colipase-mediated triacylglycerol hydrolysis is required for cholesterol transport from lipid emulsions to intestinal cells
| Autor: | Young, S C, Hui, D Y |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1999 |
| Předmět: |
Taurocholic Acid
Phospholipases A Cell Line Glycerides Lactones Mice Animals Colipases Intestinal Mucosa Pancreas Triglycerides Orlistat Hydrolysis Fatty Acids Biological Transport Lipase Lipid Metabolism Lipids Rats Mice Inbred C57BL Phospholipases A2 Cholesterol Phosphatidylcholines lipids (amino acids peptides and proteins) Emulsions Female Triolein Research Article |
| Popis: | This study tested the hypothesis that dietary cholesterol uptake by intestinal cells is dependent on the structure and composition of the lipid carriers in the extracellular milieu. In in vivo experiments with female C57BL/6 mice, cholesterol absorption from phospholipid/triacylglycerol emulsions was significantly reduced by administration of tetrahydrolipstatin, an inhibitor of pancreatic lipase. This inhibitor had no effect on the absorption of cholesterol from phospholipid vesicles. The importance of pancreatic-lipase-mediated triacylglycerol hydrolysis for cholesterol transport from emulsions to intestinal cells was confirmed by in vitro experiments with rat IEC-6 intestinal cells. Cellular uptake of cholesterol from emulsions with a phospholipid/triacylglycerol molar ratio of 0.3. Phospholipase A2-mediated hydrolysis of the surface phospholipids was necessary prior to triacylglycerol hydrolysis in these phospholipid-rich emulsions and to the stimulation of cholesterol transport from these particles to IEC-6 cells. The data also revealed that minimal triacylglycerol hydrolysis was sufficient to significantly increase cholesterol transport from lipid emulsions to the intestinal cells. Thus the products of triacylglycerol hydrolysis, namely monoacylglycerol and non-esterified fatty acids, are key determinants in mediating cholesterol transport from lipid emulsions to intestinal cells. Taken together, these results support the hypothesis that remodelling of the surface and core components of lipid carriers is necessary prior to absorption of dietary cholesterol from the gastrointestinal tract. |
| Databáze: | OpenAIRE |
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