Effects of chronic ethanol administration on hepatic glycoprotein secretion in the rat

Journal Article · Tue Mar 01 04:00:00 EST 1983 · Gastroenterology; (United States)

OSTI ID:6183236

Sorrell, M F; Nauss, J M; Donohue, Jr, T M; Tuma, D J

The effects of chronic ethanol feeding on protein and glycoprotein synthesis and secretion were studied in rat liver slices. Liver slices from rats fed ethanol for 4-5 wk showed a decreased ability to incorporate (/sup 14/C)glucosamine into medium trichloracetic acid-precipitable proteins when compared to the pair-fed controls; however, the labeling of hepatocellular glycoproteins was unaffected by chronic ethanol treatment. Immunoprecipitation of radiolabeled secretory (serum) glycoproteins with antiserum against rat serum proteins showed a similar marked inhibition in the appearance of glucosamine-labeled proteins in the medium of slices from ethanol-fed rats. Minimal effects, however, were noted in the labeling of intracellular secretory glycoproteins. Protein synthesis, as determined by measuring (/sup 14/C)leucine incorporation into medium and liver proteins, was decreased in liver slices from ethanol-fed rats as compared to the pair-fed controls. This was the case for both total proteins as well as immunoprecipitable secretory proteins, although the labeling of secretory proteins retained in the liver slices was reduced to a lesser extent than total radiolabeled hepatic proteins. When the terminal sugar, (/sup 14/C)fucose, was employed as a precursor in order to more closely focus on the final steps of hepatic glycoprotein secretion, liver slices obtained from chronic ethanol-fed rats exhibited impaired secretion of fucose-labeled proteins into the medium. When ethanol (5 or 10 mM) was added to the incubation medium containing liver slices from the ethanol-fed rats, the alterations in protein and glycoprotein synthesis and secretion caused by the chronic ethanol treatment were further potentiated. The results of this study indicate that liver slices prepared from chronic ethanol-fed rats exhibit both impaired synthesis and secretion of proteins and glycoproteins, and these defects are further potentiated by acute ethanol administration.

• Research Organization: Liver Study Unit, Veterans Administration Medical Center, Omaha, Nebraska
• OSTI ID: 6183236
• Journal Information: Gastroenterology; (United States), Journal Name: Gastroenterology; (United States) Vol. 84:3; ISSN GASTA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALCOHOLS
ANIMALS
BIOLOGICAL EFFECTS
BIOSYNTHESIS
BODY
CARBOHYDRATES
CARBON 14 COMPOUNDS
COMPARATIVE EVALUATIONS
DIGESTIVE SYSTEM
ETHANOL
GLANDS
GLUCOPROTEINS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIVER
MAMMALS
METABOLISM
ORGANIC COMPOUNDS
ORGANS
PHYSIOLOGY
PROTEINS
RATS
RODENTS
SACCHARIDES
SECRETION
SYNTHESIS
TOXICITY
TRACER TECHNIQUES
VERTEBRATES