Skip to main content
Log in

In vitro desaturation and elongation of rumenic acid by rat liver microsomes

  • Articles
  • Published:
Lipids

Abstract

Various nutritional studies on CLA, a mixture of isomers of linoleic acid, have reported the occurrence of conjugated long-chain PUFA after feeding experimental animals with rumenic acid, 9c,11t–18∶2, the major CLA isomer, probably as a result of successive desaturation and chain elongation. In the present work, in vitro studies were carried out to obtain information on the conversion of rumenic acid. Experiments were first focused on the in vitro Δ6-desaturation of rumenic acid, the regulatory step in the biosynthesis of long-chain n−6 PUFA. The conversion of rumenic acid was compared to that of linoleic acid (9c,12c–18∶2). Isolated rat liver microsomes were incubated with radiolabeled 9c,12c–18∶2 and 9c,11t–18∶2 under desaturation conditions. The data indicated that [1-14C]9c,11t–18∶2 was a poorer substrate for Δ6-desaturase than [1-14C]-9c,12c–18∶2. Next, in vitro elongation of 6c,9c,11t–18∶3 and 6c,9c,12c–18∶3 (γ-linolenic acid) was investigated in rat liver microsomes. Under elongation conditions, [1-14C]6c,9c,11t–18∶3 was 1.5-fold better converted into [3-14C]8c,11c,13t–20∶3 than [1-14C]6c,9c,12c–18∶3 into [3-14C]8c,11c,14c–20∶3. Finally, in vitro Δ5-desaturation of 8c,11c,13t–20∶3 compared to 8c,11c,14c–20∶3 was investigated. The conversion level of [1-14C]8c,11c,13t–20∶3 into [1-14C]5c,8c,11c,13t–20∶4 was 10 times lower than that of [1-14C]8c,11c,14c–20∶3 into [1-14C]5c,8c,11c,14c–20∶4 at low substrate concentrations and 4 times lower at the saturating substrate level, suggesting that conjugated 20∶3 is a poor substrate for the Δ5-desaturase.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

Abbreviations

Arachidonic acid:

5c,8c,11c,14c–20∶4n−6

behenic acid:

23∶0; dihomo-γ-linolenic acid, 8c,11c,14c–20∶3

lignoceric acid:

24∶0; linoleic acid, 9c,12c–18∶2

γ-linolenic acid:

6c,9c,12c–18∶3

rumenic acid:

9c,11t–18∶2

References

  1. Kepler, C.R., and Tove, S.B. (1967) Biohydrogenation of Unsaturated Fatty Acids, J. Biol. Chem. 242, 5686–5692.

    PubMed  CAS  Google Scholar 

  2. Hughes, P.E., Hunter, W.J., and Tove, S.B., (1982) Biohydrogenation of Unsaturated Fatty Acids: Purification and Properties of cis-9,trans-11-Octadecadienoate Reductase, J. Biol. Chem. 257, 3643–3649.

    PubMed  CAS  Google Scholar 

  3. Griinari, J.M., and Bauman, D.E. (1999) Biosynthesis of Conjugated Linoleic Acid and Its Incorporation into Meat and Milk in Ruminants, in Advances in Conjugated Linoleic Acid Research, Vol. 1 (Yurawecz, M.P., Mossoba, M.M., Kramer, J.K.G., Pariza, M.W., and Nelson, G.J., eds.), pp. 180–200, AOCS Press, Champaign.

    Google Scholar 

  4. Cawood, P., Wickens, D.G., Iversen, S.A., Braganza, J.M., and Dormandy, T.L. (1983) The Nature of Diene Conjugation in Human Serum, Bile and Duodenal Juice, FEBS Lett. 162, 239–243.

    Article  PubMed  CAS  Google Scholar 

  5. Banni, S., Day, B.W., Evans, R.W., Corongiu, F., and Lombardi, B. (1994) Liquid Chromatographic-Mass Spectrometric Analysis of Conjugated Diene Fatty Acids in a Partially Hydrogenated Fat, J. Am. Oil Chem. Soc. 71, 1321–1325.

    CAS  Google Scholar 

  6. Banni, S., and Martin, J.C. (1998) Conjugated Linoleic Acid and Metabolites, in Trans Fatty Acids in Human Nutrition (Sébédio, J.L., and Christie, W.W., eds.), pp. 261–302, The Oily Press, Dundee.

    Google Scholar 

  7. Sébédio, J.L., Gnädig, S., and Chardigny, J.M. (1999) Recent Advances in Conjugated Linoleic Acid, Curr. Opin. Clin. Nutr. Metab. Care 2, 499–506.

    Article  PubMed  Google Scholar 

  8. Pariza, M.W., Park, Y., and Cook, M.E. (2000) Mechanisms of Action of Conjugated Linoleic Acid: Evidence and Speculation, Proc. Soc. Exp. Biol. Med. 223, 8–13.

    Article  PubMed  CAS  Google Scholar 

  9. Park, Y., Albright, K.J., Liu, W., Storkson, J.M., Cook, M.E., and Pariza, M.W. (1997) Effect of Conjugated Linoleic Acid on Body Composition in Mice, Lipids 32, 853–858.

    Article  PubMed  CAS  Google Scholar 

  10. Dugan, M.E.R., Aalhus, J.L., Schaefer, A.L., and Kramer, J.K.G. (1997) The Effect of Conjugated Linoleic Acid on Fat to Lean Repartitioning and Feed Conversion in Pigs, Can. J. Anim. Sci. 77, 723–725.

    Article  CAS  Google Scholar 

  11. Banni, S., Angioni, E., Casu, V., Melis, M.P., Carta, G., Corongiu, F.P., Thompson, H., and Ip, C. (1999) Decrease in Linoleic Acid Metabolites as a Potential Mechanism in Cancer Risk Reduction by Conjugated Linoleic Acid, Carcinogenesis 20, 1019–1024.

    Article  PubMed  CAS  Google Scholar 

  12. Sébédio, J.L., Juaneda, P., Dobson, G., Ramilison, I., Martin, J.C., Chardigny, J.M., and Christie, W.W. (1997) Metabolites of Conjugated Isomers of Linoleic Acid (CLA) in the Rat, Biochim. Biophys. Acta 1345, 5–10.

    PubMed  Google Scholar 

  13. Sébédio, J.L., Angioni, E., Chardigny, J.M., Grégoire, S., Juanéda, P., and Berdeaux, O. (2001) The Effect of Conjugated Linoleic Acid Isomers on Fatty Acid Profiles of Liver and Adipose Tissues and Their Conversion to Isomers of 16∶2 and 18∶3 Conjugated Fatty Acids in Rats, Lipids 36, 575–582.

    PubMed  Google Scholar 

  14. Belury, M.A., and Kempa-Steczko, A. (1997) Conjugated Linoleic Acid Modulates Hepatic Lipid Composition in Mice, Lipids 32, 199–204.

    Article  PubMed  CAS  Google Scholar 

  15. Bretillon, L., Chardigny, J.M., Grégoire, S., Berdeaux, O., and Sébédio, J.L. (1999) Effects of Conjugated Linoleic Acid Isomers on the Hepatic Microsomal Desaturation Activities in vitro, Lipids 34, 965–969.

    Article  PubMed  CAS  Google Scholar 

  16. Loreau, O., Maret, A., Chardigny, J.M., Sébédio, J.L., and Noël, J.P. (2001) Sequential Substitution of 1,2-Dichloro-ethene: A Convenient Stereoselective Route to (9Z,11E-, (10E,12Z)-and (10Z,12Z)-[1-14C] Conjugated Linoleic Acid Isomers, Chem. Phys. Lipids 110, 57–67.

    Article  PubMed  CAS  Google Scholar 

  17. Gnädig, S., Berdeaux, O., Loreau, O., Noël, J.P., and Sébédio, J.L. (2001) Synthesis of (6Z,9Z,11E)-Octadecatrienoic and (8Z,11Z,13E)-Eicosatrienoic Acids and Their [1-14C]-Radiolabeled Analogs, Chem. Phys. Lipids 112, 121–135.

    Article  PubMed  Google Scholar 

  18. Berdeaux, O., Blond, J.P., Bretillon, L., Chardigny, J.M., Mairot, T., Vatèle, J.M., Poullain, D., and Sébédio, J.L. (1998) In vitro Desaturation or Elongation of Monotrans Isomers of Linoleic Acid by Rat Liver Microsomes, Mol. Cell. Biochem. 185, 17–25.

    Article  PubMed  CAS  Google Scholar 

  19. Lowry, O.H., Rosebrough, N.J., Farr, A.L., and Randall, R.J. (1951) Protein Measurement with the Folin Phenol Reagent, J. Biol. Chem. 193, 265–275.

    PubMed  CAS  Google Scholar 

  20. Mohrhauer, H., Christiansen, K., Gan, M.V., Deubic, M., and Holman, R.T. (1967) Chain Elongation of Linoleic Acid and Its Inhibition by Other Fatty Acids in vitro, J. Biol. Chem. 242, 4507–4514.

    PubMed  CAS  Google Scholar 

  21. Mohrhauer, H., and Holman, R. (1963) The Effect of Dose Level of Essential Fatty Acids upon Fatty Acid Composition of the Rat Liver, J. Lipid Res. 4, 151–159.

    PubMed  CAS  Google Scholar 

  22. Cook, H.W. (1991) Fatty Acid Desaturation and Chain Elongation in Eucaryotes, in Biochemistry of Lipids, Lipoproteins and Membranes (Vance, D.E., and Vance, J. eds.), pp. 141–169, Elsevier Science, New York.

    Google Scholar 

  23. Cao, J., Blond, J.P., and Bézard, J. (1993) Inhibition of Fatty Acid Δ6- and Δ5-Desaturation by Cyclopropene Fatty Acids in Rat Liver Microsomes, Biochim. Biophys. Acta 1210, 27–34.

    PubMed  CAS  Google Scholar 

  24. Sébédio, J.L. (1994) Classical Chemical Techniques for Fatty Acid Analysis, in New Trends in Lipids and Lipoprotein Analysis (Sébédio, J.L., and Perkins, E.G., eds.), pp. 277–289, AOCS Press, Champaign.

    Google Scholar 

  25. Brenner, R.R. (1971) The Desaturation Step in Animal Biosynthesis of Polyunsaturated Fatty Acids, Lipids 6, 567–571.

    PubMed  CAS  Google Scholar 

  26. Banni, S., Carta, G., Angioni, E., Murru, E., Scanu, P., Melis, M.P., Bauman, D.E., Fischer, S.M., and Ip, C. (2001) Distribution of Conjugated Linoleic Acid and Metabolites in Different Lipid Fractions in the Rat Liver, J. Lipid Res. 42, 1056–1061.

    PubMed  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to O. Berdeaux.

About this article

Cite this article

Berdeaux, O., Gnädig, S., Chardigny, J.M. et al. In vitro desaturation and elongation of rumenic acid by rat liver microsomes. Lipids 37, 1039–1045 (2002). https://doi.org/10.1007/s11745-002-0998-8

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11745-002-0998-8

Keywords

Navigation