Advertisement

Pflügers Archiv

, Volume 427, Issue 1–2, pp 96–101 | Cite as

The hydrolysis of glycerol-3-phosphate into glycerol in cardiac tissue: possible consequences for the validity of glycerol release as a measure of lipolysis

  • Monique J. M. de Groot
  • Yvonne F. de Jong
  • Will A. Coumans
  • Ger J. van der Vusse
Heart, Circulation, Respiration and Blood; Environmental and Exercise Physiology

Abstract

Glycerol release has been generally accepted as an index of lipolysis in the intact heart. The glycerol moiety of glycerol-3-phosphate (glycerol-3-P) is incorporated into triacylglycerols, which are then hydrolysed with release of glycerol. This study investigates the possibility that glycerol may be derived directly from glycerol-3-P instead of passing through the triacylglycerol pool. The cardiac capacity for hydrolysis of glycerol-3-P into glycerol was determined in homogenates of rat hearts. Glycerol-3-P hydrolysis activity in homogenates increased with decreasing pH. The activity was approximately four times higher at pH 5.0 than at pH 7.2 (0.94±0.11 and 0.25±0.03 μmol · g wet weight−1 · min−1respectively). The substrate concentration at which half-maximal glycerol-3-P hydrolysis activity was reached did not significantly differ at pH 5.0 and pH 7.2 (4.2±1.1 mM and 2.9±1.0 mM respectively). In the intact heart, the pH and substrate conditions found under ischaemia are favourable for direct conversion of glycerol-3-P into glycerol. The glycerol-3-P hydrolysis activity measured in vitro was sufficiently high to account for glycerol production in the ischaemia heart. However, the lack of a stoichiometric relation between cardiac glycerol-3-P and glycerol levels in ischaemia indicates that production of glycerol cannot be explained solely by hydrolysis.

Key words

Glycerol-3-P Glycerol Heart Ischaemia Lipolysis 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Bergmeyer HU, Bernt E (1974) UV assay for lactate dehydrogenase with pyruvate and NADH. In: Bergmeyer HU (ed) Methods of enzymatic analysis Vol 2. Verlag Chemie, Weinheim, pp 574–579Google Scholar
  2. 2.
    Cobbe SM, Poole-Wilson PA (1980) The time of onset and severity of acidosis in myocardial ischaemia. J Mol Cell Cardiol 12:745–760Google Scholar
  3. 3.
    De Groot MJM, Coumans WA, Willemsen PHM, Van der Vusse GJ (1993) Substrate-induced changes in the lipid content of ischemic and reperfused myocardium. Its relation to hemodynamic recovery. Circ Res 72:176–186Google Scholar
  4. 4.
    De Groot MJM, Willemsen PHM, Coumans WA, Van Bilsen M, Van der Vusse GJ (1989) Lactate induced stimulation of myocardial triacylglycerol turnover. Biochim Biophys Acta 1006:111–115Google Scholar
  5. 5.
    Denton RM, Randle PJ (1967) Measurement of flow of carbon atoms from glucose and glycogen glucose to glyceride glycerol and glycerol in rat heart and epididymal adipose tissue. Biochem J 104:423–434Google Scholar
  6. 6.
    Gohil K, Jones DA, Edwards RHT (1981) Analysis of muscle mitochondrial function with techniques applicable to needle biopsy samples. Clin Physiol 1:195–207Google Scholar
  7. 7.
    Hülsmann WC, Stam H (1979) Lipolysis in heart and adipose tissue, effects of inhibition of glycogenolysis and uncoupling of oxidative phosphorylation. Biochem Biophys Res Commun 88:867–872Google Scholar
  8. 8.
    Idell-Wenger JA, Grotyohann LW, Neely JR (1978) Coenzyme A and carnitine distribution in normal and ischemic hearts. J Biol Chem 253:4310–4318Google Scholar
  9. 9.
    Koldovsky O, Palmieri M (1971) Cortisone-evoked decrease of acidβ-galactosidase,β-glucuronidase,N-acetyl-β-glucosaminidase and arylsulphatase in the ileum of suckling rats. Biochem J 125:697–701Google Scholar
  10. 10.
    Laurell S, Tibbling G (1966) An enzymatic fluorometric micromethod for the determination of glycerol. Clin Chim Acta 13:317–322Google Scholar
  11. 11.
    Lowry OH, Rosebrough NJ, Farr AL, Randall RJ (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193:265–275Google Scholar
  12. 12.
    Myrmel T, Larsen T, Skulberg A, Forsdahl K, Little C (1989) Phospholipase C-evoked glycerol release in energy depleted rat myocardial cells. Mol Cell Biochem 88:107–111Google Scholar
  13. 13.
    Myrmel T, Forsdahl K, Sager G, Larsen TS (1991) Regulation of lipolysis in normoxic and hypoxic rat myocytes. J Mol Cell Cardiol 23:207–215Google Scholar
  14. 14.
    Nalbone G, Hostetler KY (1985) Subcellular localization of the phospholipases A of rat heart: evidence for a cytosolic phospholipase A1. J Lipid Res 26:104–114Google Scholar
  15. 15.
    Robinson J, Newsholme EA (1967) Glycerol kinase activities in rat heart and adipose tissue. Biochem J 104:2c-4cGoogle Scholar
  16. 16.
    Scheuer J, Olson RE (1967) Metabolism of exogenous triglyceride by the isolated perfused rat heart. Am J Physiol 212:301–307Google Scholar
  17. 17.
    Schwertz DW, Halverson JB, Isaacson T, Feinberg H, Palmer JW (1987) Alterations in phospholipid metabolism in the globally ischemic rat heart: emphasis on phosphoinositide specific phospholipase C activity. J Mol Cell Cardiol 19:685–697Google Scholar
  18. 18.
    Sottocosa GL, Kuylenstierna B, Ernster L, Bergstrand A (1967) An electron-transport system associated with the outer membrane of liver mitochondria. J Cell Biol 32:415–438Google Scholar
  19. 19.
    Stam H, Broekhoven-Schokker S, Hülsmann WC (1986) Characterization of mono-, di- and triacylglycerol lipase activities in the isolated rat heart. Biochim Biophys Acta 875:76–86Google Scholar
  20. 20.
    Trach V, Buschmans-Denkel E, Schaper W (1986) Relation between lipolysis and glycolysis during ischemia in the isolated rat heart. Basic Res Cardiol 81:454–464Google Scholar
  21. 21.
    Van Belle H (1970) New and sensitive reaction for automatic determination of inorganic phosphate and its application to serum. Anal Biochem 33:132–142Google Scholar
  22. 22.
    Van Bilsen M, Van der Vusse GJ, Willemsen PHM, Coumans WA, Roemen THM, Reneman RS (1989) Lipid alterations in isolated, working rat hearts during ischemia and reperfusion: its relation to myocardial damage. Circ Res 64:304–314Google Scholar
  23. 23.
    Van Bilsen M, Snoeckx LHEH, Arts T, Van der Vusse GJ, Reneman RS (1991) Performance of the isolated ejecting heart: effects of aortic impedance and exogenous substrates. Pflügers Arch 419:7–12Google Scholar
  24. 24.
    Van der Vusse GJ, Glatz JFC, Stam HCG, Reneman RS (1992) Fatty acid homeostasis in the normoxic and ischemic heart. Physiol Rev 72: 881–940Google Scholar

Copyright information

© Springer-Verlag 1994

Authors and Affiliations

  • Monique J. M. de Groot
    • 1
  • Yvonne F. de Jong
    • 2
  • Will A. Coumans
    • 1
  • Ger J. van der Vusse
    • 2
  1. 1.Department of Physiology, Cardiovascular Research Institute MaastrichtUniversity of LimburgMaastrichtThe Netherlands
  2. 2.Department of Motion Science, Cardiovascular Research Institute MaastrichtUniversity of LimburgMaastrichtThe Netherlands

Personalised recommendations