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In vivo Liver Endocytosis Followed by Purification of Liver Cells by Liver Perfusion
Published on: November 10, 2011
Secretion of biliary lipids from the hepatocyte
M P Marzolo1, A Rigotti, F Nervi
1Departamento de Gastroenterología, Facultad de Medicina, Pontificia Universidad Católica, Santiago, Chile.
Hepatology (Baltimore, Md.)
|September 1, 1990
Summary
Biliary cholesterol is primarily transported in phospholipid vesicles, originating from hepatocytes. Bile acid secretion influences cholesterol and phospholipid release, with intrahepatic factors playing a key role.
Area of Science:
- Hepatobiliary Science
- Cell Biology
- Lipid Metabolism
Background:
- Biliary cholesterol is predominantly found in unilamellar-phospholipid vesicles in both human and rat bile.
- This supports the hypothesis that hepatocytes secrete cholesterol within phospholipid vesicles into the bile canaliculus.
Purpose of the Study:
- To investigate the quantitative determinants and cell biology of hepatocytic cholesterol secretion into bile.
- To explore the relationship between bile acid secretion and biliary lipid output.
- To examine the influence of intrahepatic factors on biliary cholesterol secretion.
Main Methods:
- Analysis of biliary cholesterol and phospholipid content in human and rat bile.
- Review of existing literature on biliary lipid secretion and cellular mechanisms.
Main Results:
- A strong correlation exists between bile acid secretion rates and biliary lipid secretion across species.
- Bile acid hydrophobicity has a minor effect on lipid recruitment.
- Intrahepatic factors like cholesterol esterification and VLDL production significantly impact biliary cholesterol content.
- Free cholesterol availability in the endoplasmic reticulum influences biliary cholesterol output.
Conclusions:
- Biliary cholesterol is secreted from hepatocytes within phospholipid vesicles.
- Bile acid secretion is coupled to biliary lipid secretion, with intrahepatic factors being major modulators.
- The precise intracellular transport and secretion mechanisms remain largely undefined, with fusion-budding and exocytotic models proposed.
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