Skip to main content
PMC home page
Biochemical Journal logoLink to Biochemical Journal
. 1990 Aug 15;270(1):219–225. doi: 10.1042/bj2700219

Measurement of the rates of acetyl-CoA hydrolysis and synthesis from acetate in rat hepatocytes and the role of these fluxes in substrate cycling.

B Crabtree 1, M J Gordon 1, S L Christie 1
PMCID: PMC1131701  PMID: 2396982

Abstract

1. Acetyl-CoA hydrolysis, acetyl-CoA synthesis from acetate and several related fluxes were measured in rat hepatocytes. 2. In contrast with acetyl-CoA hydrolysis, most of the acetyl-CoA synthesis from acetate occurred in the mitochondria. 3. Acetyl-CoA hydrolysis was not significantly affected by 24 h starvation or (-)-hydroxycitrate. 4. In the cytoplasm there was a net flux of acetyl-CoA to acetate, and substrate cycling between acetate and acetyl-CoA in this compartment was very low, accounting for less than 0.1% of the total heat production by the animal. 5. A larger cycle, involving mitochondrial and cytoplasmic acetate and acetyl-CoA, may operate in fed animals, but would account for only approx 1% of total heat production. 6. It is proposed that the opposing fluxes of mitochondrial acetate utilization and cytoplasmic net acetate production may provide sensitivity, feedback and buffering, even when these fluxes are not linked to form a conventional substrate cycle.

Full text

PDF
219

Selected References

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

  1. Ballard F. J. Supply and utilization of acetate in mammals. Am J Clin Nutr. 1972 Aug;25(8):773–779. doi: 10.1093/ajcn/25.8.773. [DOI] [PubMed] [Google Scholar]
  2. Baranyai J. M., Blum J. J. Quantitative analysis of intermediary metabolism in rat hepatocytes incubated in the presence and absence of ethanol with a substrate mixture including ketoleucine. Biochem J. 1989 Feb 15;258(1):121–140. doi: 10.1042/bj2580121. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Barth C., Sladek M., Decker K. Dietary changes of cytoplasmic acetyl-CoA synthetase in different rat tissues. Biochim Biophys Acta. 1972 Jan 27;260(1):1–9. doi: 10.1016/0005-2760(72)90067-7. [DOI] [PubMed] [Google Scholar]
  4. Bieber L. L. Carnitine. Annu Rev Biochem. 1988;57:261–283. doi: 10.1146/annurev.bi.57.070188.001401. [DOI] [PubMed] [Google Scholar]
  5. Blaise G., Noël J., Vinay P., Cardoso M., Vinet B., Boulanger Y., Léveillé M., Prud'homme M., Gougoux A. Metabolic effects of acetate on the heart. Clin Invest Med. 1989 Aug;12(4):254–261. [PubMed] [Google Scholar]
  6. Brunengraber H., Boutry M., Lowenstein J. M. Fatty acid and 3- -hydroxysterol synthesis in the perfused rat liver. Including measurements on the production of lactate, pyruvate, -hydroxy-butyrate, and acetoacetate by the fed liver. J Biol Chem. 1973 Apr 25;248(8):2656–2669. [PubMed] [Google Scholar]
  7. Brunengraber H., Sabine J. R., Boutry M., Lowenstein J. M. 3- -Hydroxysterol synthesis by the liver. Arch Biochem Biophys. 1972 Jun;150(2):392–396. doi: 10.1016/0003-9861(72)90054-9. [DOI] [PubMed] [Google Scholar]
  8. Buckley B. M., Williamson D. H. Origins of blood acetate in the rat. Biochem J. 1977 Sep 15;166(3):539–545. doi: 10.1042/bj1660539. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Crabtree B., Marr S. A., Anderson S. E., MacRae J. C. Measurement of the rate of substrate cycling between acetate and acetyl-CoA in sheep muscle in vivo. Effects of infusion of acetate. Biochem J. 1987 May 1;243(3):821–827. doi: 10.1042/bj2430821. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Crabtree B., Souter M. J., Anderson S. E. Evidence that the production of acetate in rat hepatocytes is a predominantly cytoplasmic process. Biochem J. 1989 Feb 1;257(3):673–678. doi: 10.1042/bj2570673. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. French T. J., Good A. W., Palmer T. N., Sugden M. C. Effects of dexamethasone on carnitine metabolism in liver and extrahepatic tissues. Biosci Rep. 1985 Sep;5(9):729–734. doi: 10.1007/BF01119870. [DOI] [PubMed] [Google Scholar]
  12. Goldberg R. P., Brunengraber H. Contributions of cytosolic and mitochondrial acetyl-CoA syntheses to the activation of lipogenic acetate in rat liver. Adv Exp Med Biol. 1980;132:413–418. doi: 10.1007/978-1-4757-1419-7_41. [DOI] [PubMed] [Google Scholar]
  13. Groot P. H., Scholte H. R., Hülsmann W. C. Fatty acid activation: specificity, localization, and function. Adv Lipid Res. 1976;14:75–126. doi: 10.1016/b978-0-12-024914-5.50009-7. [DOI] [PubMed] [Google Scholar]
  14. Knowles S. E., Jarrett I. G., Filsell O. H., Ballard F. J. Production and utilization of acetate in mammals. Biochem J. 1974 Aug;142(2):401–411. doi: 10.1042/bj1420401. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Kondrup J., Lazarow P. B. Flux of palmitate through the peroxisomal and mitochondrial beta-oxidation systems in isolated rat hepatocytes. Biochim Biophys Acta. 1985 Jun 14;835(1):147–153. doi: 10.1016/0005-2760(85)90041-4. [DOI] [PubMed] [Google Scholar]
  16. Leighton F., Bergseth S., Rørtveit T., Christiansen E. N., Bremer J. Free acetate production by rat hepatocytes during peroxisomal fatty acid and dicarboxylic acid oxidation. J Biol Chem. 1989 Jun 25;264(18):10347–10350. [PubMed] [Google Scholar]
  17. Lowenstein J. M. Citrate and the conversion of carbohydrate into fat. Biochem Soc Symp. 1968;27:61–86. [PubMed] [Google Scholar]
  18. Lowenstein J. M. Effect of (-)-hydroxycitrate on fatty acid synthesis by rat liver in vivo. J Biol Chem. 1971 Feb 10;246(3):629–632. [PubMed] [Google Scholar]
  19. Matsunaga T., Isohashi F., Nakanishi Y., Sakamoto Y. Physiological changes in the activities of extramitochondrial acetyl-CoA hydrolase in the liver of rats under various metabolic conditions. Eur J Biochem. 1985 Oct 15;152(2):331–336. doi: 10.1111/j.1432-1033.1985.tb09202.x. [DOI] [PubMed] [Google Scholar]
  20. Mayes P. A., Topping D. L. Regulation of hepatic lipogenesis by plasma free fatty acids: simultaneous studies on lipoprotein secretion, cholesterol synthesis, ketogenesis and gluconeogenesis. Biochem J. 1974 Apr;140(1):111–114. doi: 10.1042/bj1400111. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Newsholme E. A., Crabtree B. Substrate cycles in metabolic regulation and in heat generation. Biochem Soc Symp. 1976;(41):61–109. [PubMed] [Google Scholar]
  22. Pogson C. I., Carpenter W. R., Cook J. S., Fisher M. J., Lomax M. A., Salter M., Stanley J. C. A critical approach to the use of isolated liver cells for the study of metabolic events. Proc Nutr Soc. 1984 Jun;43(2):119–132. doi: 10.1079/pns19840036. [DOI] [PubMed] [Google Scholar]
  23. Prass R. L., Isohashi F., Utter M. F. Purification and characterization of an extramitochondrial acetyl coenzyme A hydrolase from rat liver. J Biol Chem. 1980 Jun 10;255(11):5215–5223. [PubMed] [Google Scholar]
  24. Rabkin M., Blum J. J. Quantitative analysis of intermediary metabolism in hepatocytes incubated in the presence and absence of glucagon with a substrate mixture containing glucose, ribose, fructose, alanine and acetate. Biochem J. 1985 Feb 1;225(3):761–786. doi: 10.1042/bj2250761. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Scholte H. R., Groot P. H. Organ and intracellular localization of short-chain acyl-CoA synthetases in rat and guinea-pig. Biochim Biophys Acta. 1975 Dec 17;409(3):283–296. doi: 10.1016/0005-2760(75)90024-7. [DOI] [PubMed] [Google Scholar]
  26. Siess E. A., Brocks D. G., Lattke H. K., Wieland O. H. Effect of glucagon on metabolite compartmentation in isolated rat liver cells during gluconeogenesis from lactate. Biochem J. 1977 Aug 15;166(2):225–235. doi: 10.1042/bj1660225. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Snoswell A. M., Trimble R. P., Fishlock R. C., Storer G. B., Topping D. L. Metabolic effects of acetate in perfused rat liver. Studies on ketogenesis, glucose output, lactate uptake and lipogenesis. Biochim Biophys Acta. 1982 Jun 16;716(3):290–297. doi: 10.1016/0304-4165(82)90019-8. [DOI] [PubMed] [Google Scholar]
  28. Söling H. D., Rescher C. On the regulation of cold-labile cytosolic and of mitochondrial acetyl-CoA hydrolase in rat liver. Eur J Biochem. 1985 Feb 15;147(1):111–117. doi: 10.1111/j.1432-1033.1985.tb08726.x. [DOI] [PubMed] [Google Scholar]
  29. Watson J. A., Lowenstein J. M. Citrate and the conversion of carbohydrate into fat. Fatty acid synthesis by a combination of cytoplasm and mitochondria. J Biol Chem. 1970 Nov 25;245(22):5993–6002. [PubMed] [Google Scholar]

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

RESOURCES