Subcellular location of secretory proteins retained in the liver during the ethanol-induced inhibition of hepatic protein secretion in the rat
Ethanol administration inhibits the secretion of proteins by the liver, resulting in their hepatocellular retention. Experiments were designed in this study to determine the subcellular location of the retained secretory proteins. Ethanol was administered acutely to nonfasted rats by gastric intubation, whereas control animals received an isocaloric dose of glucose. Two hours after intubation, when maximum blood ethanol levels (45 mM) were observed, (/sup 3/H)leucine and (/sup 14/C)fucose were injected simultaneously into the dorsal vein of the penis. The labelling of secretory proteins was determined in the liver and plasma at various time periods after label injection. Ethanol treatment decreased the secretion of both leucine- and fucose-labeled proteins into the plasma. This inhibition of secretion was accompanied by a corresponding increase in the hepatic retention of both leucine- and fucose-labeled immunoprecipitable secretory proteins. At the time of maximum inhibition of secretion, leucine labeled secretory proteins located in the Golgi apparatus represented about 50% of the accumulated secretory proteins in the livers of the ethanol-treated rats, whereas the remainder was essentially equally divided among the rough and smooth endoplasmic reticulum and cytosol. Because fucose is incorporated into secretory proteins almost exclusively in the Golgi complex, fucose-labeled proteins accumulated in the livers of the ethanol-treated rats mainly in the Golgi apparatus, with the remainder located in the cytosol. These results show that ethanol administration causes an impaired movement of secretory proteins along the secretory pathway, and that secretory proteins accumulate mainly, but not exclusively, in the Golgi apparatus.
- OSTI ID:
- 5842792
- Journal Information:
- Gastroenterology; (United States), Vol. 1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effect of chronic ethanol on hepatic apolipoprotein (Apo)E glycosylation
Influence of colchicine and vinblastine on the intracellular migration of secretory and membrane glycoproteins: III. Inhibition of intracellular migration of membrane glycoproteins in rat intestinal columnar cells and hepatocytes as visualized by light and electron-microscope radioautography after 3H-fucose injection
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ETHANOL
BIOLOGICAL EFFECTS
PROTEINS
RETENTION
SECRETION
CARBON 14 COMPOUNDS
HEXOSES
LABELLING
LEUCINE
LIVER
ORGANOIDS
RATS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ALCOHOLS
AMINO ACIDS
ANIMALS
BODY
CARBOHYDRATES
CARBOXYLIC ACIDS
CELL CONSTITUENTS
DIGESTIVE SYSTEM
GLANDS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MONOSACCHARIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
RODENTS
SACCHARIDES
VERTEBRATES
560305* - Chemicals Metabolism & Toxicology- Vertebrates- (-1987)
550501 - Metabolism- Tracer Techniques