Skip to main content
PMC home page
Biochemical Journal logoLink to Biochemical Journal
. 1991 Jan 1;273(Pt 1):149–152. doi: 10.1042/bj2730149

Inhibition of proteolysis in the liver by chronic ethanol feeding.

A R Pösö 1, P Hirsimäki 1
PMCID: PMC1149891  PMID: 1989576

Abstract

Effects of chronic ethanol feeding on the volume density of lysosomes, the rate of protein degradation and the amount of protein were studied in livers perfused in situ at 07:00, 11:00, 17:00 and 23:00 h. Ethanol was given to the rats in drinking water for either 3 or 8-10 weeks. During week 3 of treatment and onwards, the average daily consumption of ethanol was 12.3 +/- 0.3 g/kg body wt. Morphometric analysis revealed that the volume density of autophagosomes and autolysosomes was lower in the ethanol-fed rats than in the controls. When compared with age-matched controls, the rate of proteolysis, measured as release of valine, was 33% and 26% less in the ethanol-fed rats after treatment for 3 and 8-10 weeks respectively. The difference between the two groups was most pronounced at 07:00 and 11:00 h. Protein content of the liver increased significantly after the longer ethanol treatment. According to these results, chronic ethanol feeding inhibits proteolysis in the liver by preventing the sequestration of protein into lysosomes.

Full text

PDF
149

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Adibi S. A., Modesto T. A., Morse E. L., Amin P. M. Amino acid levels in plasma, liver, and skeletal muscle during protein deprivation. Am J Physiol. 1973 Aug;225(2):408–414. doi: 10.1152/ajplegacy.1973.225.2.408. [DOI] [PubMed] [Google Scholar]
  2. Baraona E., Lieber C. S. Effects of alcohol on hepatic transport of proteins. Annu Rev Med. 1982;33:281–292. doi: 10.1146/annurev.me.33.020182.001433. [DOI] [PubMed] [Google Scholar]
  3. Britton R. S., Videla L. A., Rachamin G., Okuno F., Israel Y. Effect of age on metabolic tolerance and hepatomegaly following chronic ethanol administration. Alcohol Clin Exp Res. 1984 Nov-Dec;8(6):528–534. doi: 10.1111/j.1530-0277.1984.tb05723.x. [DOI] [PubMed] [Google Scholar]
  4. Eriksson C. J., Sippel H. W., Forsander O. A. The determination of acetaldehyde in biological samples by head-space gas chromatography. Anal Biochem. 1977 May 15;80(1):116–124. doi: 10.1016/0003-2697(77)90631-5. [DOI] [PubMed] [Google Scholar]
  5. Eriksson K., Halkka O., Lokki J., Saura A. Enzyme polymorphism in feral, outbred and inbred rats (Rattus norvegicus). Heredity (Edinb) 1976 Dec;37(3):341–349. doi: 10.1038/hdy.1976.98. [DOI] [PubMed] [Google Scholar]
  6. Goldspink D. F., Kelly F. J. Protein turnover and growth in the whole body, liver and kidney of the rat from the foetus to senility. Biochem J. 1984 Jan 15;217(2):507–516. doi: 10.1042/bj2170507. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Goodman M. N., Larsen P. R., Kaplan M. M., Aoki T. T., Young V. R., Ruderman N. B. Starvation in the rat. II. Effect of age and obesity on protein sparing and fuel metabolism. Am J Physiol. 1980 Oct;239(4):E277–E286. doi: 10.1152/ajpendo.1980.239.4.E277. [DOI] [PubMed] [Google Scholar]
  8. Hirsimäki P., Pilström L. Studies on vinblastine-induced autophagocytosis in mouse liver. III. A quantitative study. Virchows Arch B Cell Pathol Incl Mol Pathol. 1982;41(1-2):51–66. doi: 10.1007/BF02890271. [DOI] [PubMed] [Google Scholar]
  9. Hutson N. J., Lloyd C. E., Mortimore G. E. Degradation of intra- and extrahepatic protein by livers of normal and diabetic mice: differential responses to starvation. Proc Natl Acad Sci U S A. 1982 Mar;79(6):1737–1741. doi: 10.1073/pnas.79.6.1737. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Israel Y., Oporto B., Macdonald A. D. Simultaneous pair-feeding system for the administration of alcohol-containing liquid diets. Alcohol Clin Exp Res. 1984 Sep-Oct;8(5):505–508. doi: 10.1111/j.1530-0277.1984.tb05714.x. [DOI] [PubMed] [Google Scholar]
  11. Mezey E., Potter J. J., Ammon R. A. Effect of ethanol administration on the activity of hepatic lysosomal enzymes. Biochem Pharmacol. 1976 Dec 1;25(23):2663–2667. doi: 10.1016/0006-2952(76)90524-4. [DOI] [PubMed] [Google Scholar]
  12. Mortimore G. E., Pösö A. R. Intracellular protein catabolism and its control during nutrient deprivation and supply. Annu Rev Nutr. 1987;7:539–564. doi: 10.1146/annurev.nu.07.070187.002543. [DOI] [PubMed] [Google Scholar]
  13. Mortimore G. E., Surmacz C. A. Liver perfusion: an in vitro technique for the study of intracellular protein turnover and its regulation in vivo. Proc Nutr Soc. 1984 Jun;43(2):161–177. doi: 10.1079/pns19840039. [DOI] [PubMed] [Google Scholar]
  14. Pignon J. P., Bailey N. C., Baraona E., Lieber C. S. Fatty acid-binding protein: a major contributor to the ethanol-induced increase in liver cytosolic proteins in the rat. Hepatology. 1987 Sep-Oct;7(5):865–871. doi: 10.1002/hep.1840070512. [DOI] [PubMed] [Google Scholar]
  15. Pösö A. R., Surmacz C. A., Mortimore G. E. Inhibition of intracellular protein degradation by ethanol in perfused rat liver. Biochem J. 1987 Mar 1;242(2):459–464. doi: 10.1042/bj2420459. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Pösö A. R., Wert J. J., Jr, Mortimore G. E. Multifunctional control of amino acids of deprivation-induced proteolysis in liver. Role of leucine. J Biol Chem. 1982 Oct 25;257(20):12114–12120. [PubMed] [Google Scholar]
  17. Pösö H., Vänänen H., Salaspuro M. P., Pösö A. R. Effects of ethanol on liver regeneration after partial hepatectomy in rats. Med Biol. 1980 Dec;58(6):329–336. [PubMed] [Google Scholar]
  18. Rohr H., Oberholzer M., Bartsch G., Keller M. Morphometry in experimental pathology: methods, baseline data and applications. Int Rev Exp Pathol. 1976;15:233–325. [PubMed] [Google Scholar]
  19. Schworer C. M., Shiffer K. A., Mortimore G. E. Quantitative relationship between autophagy and proteolysis during graded amino acid deprivation in perfused rat liver. J Biol Chem. 1981 Jul 25;256(14):7652–7658. [PubMed] [Google Scholar]
  20. Scornik O. A. Role of protein degradation in the regulation of cellular protein content and amino acid pools. Fed Proc. 1984 Apr;43(5):1283–1288. [PubMed] [Google Scholar]
  21. Smith-Kielland A., Blom G. P., Svendsen L., Bessesen A., Mørland J. A study of hepatic protein synthesis, three subcellular enzymes, and liver morphology in chronically ethanol fed rats. Acta Pharmacol Toxicol (Copenh) 1983 Aug;53(2):113–120. doi: 10.1111/j.1600-0773.1983.tb01877.x. [DOI] [PubMed] [Google Scholar]
  22. Uezu N., Yamamoto S., Rikimaru T., Kishi K., Inoue G. Contributions of individual body tissues to nitrogen excretion in adult rats fed protein-deficient diets. J Nutr. 1983 Jan;113(1):105–114. doi: 10.1093/jn/113.1.105. [DOI] [PubMed] [Google Scholar]

Articles from Biochemical Journal are provided here courtesy of The Biochemical Society

RESOURCES