Neurochemical Research

, Volume 18, Issue 2, pp 119–123

The two catalytic components of the 2-oxoglutarate dehydrogenase complex in rat cerebral synaptic and nonsynaptic mitochondria: Comparison of the response to in vitro treatment with ammonia, hyperammonemia, and hepatic encephalopathy

  • Lidia Faff-Michalak
  • Jan Albrecht
Original Articles

Abstract

The effects of in vitro treatment with ammonium chloride, hepatic encephalopathy (HE) due to thioacetamide (TAA) induced liver failure and chronic hyperammonemia produced by i.p. administration of ammonium acetate on the two components of the multienzyme 2-oxoglutarate dehydrogenase complex (OGDH): 2-oxoglutarate decarboxylase (E1) and lipoamide dehydrogenase (E3), were examined in synaptic and nonsynaptic mitochondria from rat brain. With regard to E1 the response to ammonium ions in vitro (3 mM NH4Cl) was observed in nonsynaptic mitochondria only and was manifested by a 21% decrease of Vmax and a 35% decrease of Km for 2-oxoglutarate (2-OG). By contrast, both in vivo conditions primarily affected the synaptic mitochondrial E1: TAA-induced HE produced an 84% increase of Vmax and a 38% increase of Km for 2-OG. Hyperammonemia elevated Vmax of E1 by 110% and Km for 2-OG by 30%. HE produced no effect at all in nonsynaptic mitochondria while hyperammonemia produced a 35% increase of Vmax and a 30% increase of Km for 2-OG of E1. Both in vivo conditions produced a 20% increase of E3 activity in synaptic mitochondria, but no effect at all in nonsynaptic mitochondria. The preferential sensitivity of E1 to ammonium chloride in vitro in nonsynaptic mitochondria and hyperammonemic conditions in vivo in synaptic mitochondria may play a crucial role in the compartmentation of OGDH responses under analogous conditions. These results confirm the intrinsic differences between the OGDH properties in the synaptic and nonsynaptic brain compartments.

Key Words

Hepatic encephalopathy hyperammonemia ammonium chloride 2-oxoglutarate decarboxylase lipoamide dehydrogenase brain mitochondria 

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References

  1. 1.
    Lai, J. C. K., and Clark, J. B. 1979. Preparation of synaptic and nonsynaptic mitochondria from mammalian brain. Pages 51–56,in Fleischer, S., and Packer, L. (eds.), Methods in Enzymology, Vol. 55, Part F, Academic Press, New York.Google Scholar
  2. 2.
    Lai, J. C. K., Walsh, J. M., Dennis, S. C., and Clark, J. B. 1977. Synaptic and nonsynaptic mitochondria from rat brain: Isolation and characterization. J. Neurochem. 28:625–631.Google Scholar
  3. 3.
    Lai, J. C. K., Walsh, J. M., Dennis, S. C., and Clark, J. B. 1975. Compartmentation of citric acid cycle and related enzymes in distinct population of rat brain mitochondria. Pages 487–496,in Berl, S., Clarke, D. D., and Schneider, D. (eds.), Metabolic Compartmentation and Neurotransmission. Relation to the Brain Structure and Function, Plenum Press, New York.Google Scholar
  4. 4.
    Lai, J. C. K., and Cooper, J. L. 1986. Brain α-ketoglutarate dehydrogenase complex: kinetic properties, regional distribution, and effect of inhibitors. J. Neurochem. 47:1376–1386.Google Scholar
  5. 5.
    Lai, J. C. K., and Cooper, J. L. 1991. Neurotoxicity of ammonia and fatty acids: Differential inhibition of mitochondrial dehydrogenases by ammonia and fatty acyl coenzyme A derivatives. Neurochem. Res. 16:795–803.Google Scholar
  6. 6.
    Faff-Michalak, L., Wysmyk-Cybula, U., and Albrecht, J. 1991. Different responses of rat cerebral mitochondrial 2-oxoglutarate dehydrogenase activity to ammonia and hepatic encephalopathy in synaptic and nonsynaptic mitochondria. Neurochem. Int. 19:573–579.Google Scholar
  7. 7.
    Benjamin, A. M., 1982. Ammonia. Pages 117–137,in Lajtha, A. (ed.), Handbook of Neurochemistry, Vol. 1, 2nd edit., Plenum Press, New York.Google Scholar
  8. 8.
    Hindfelt, B. 1983. Ammonia intoxication and brain energy metabolism. Pages 474–484,in Kleinberger, G., and Deutsch, E. (eds.) New aspects of Clinical Nutrition, Karger, Basel.Google Scholar
  9. 9.
    Kvamme, E. 1983. Ammonia metabolism in the CNS. Progr. Neurobiol. 20:109–132.Google Scholar
  10. 10.
    Norenberg, M. D. 1986. Hepatic encephalopathy: A disorder of astrocytes. Pages 425–460, in Fedoroff, S., and Vernadakis, A. (eds.), Astrocytes: Cell biology and pathology of Astrocytes, Vol. 3, Academic Press, New York.Google Scholar
  11. 11.
    Butterworth, R. H., Giguere, J. F., Michaud, J., Lavoie, J., and Pomier-Layrargues. 1987. Ammonia: Key factor in the pathogenesis of hepatic encephalopathy. Neurochem. Pathol. 6:1–12.Google Scholar
  12. 12.
    Koike, M., and Koike, K. 1976. Structure, assembly and function of mammalian α-keto acid dehydrogenase complexes. Adv. Biophys. 9:187–227.Google Scholar
  13. 13.
    Stanley, C. J., and Perham, R. N. 1980. Purification of 2-oxo acid dehydrogenase multienzyme complexes from ox heart by a new method. Biochem. J. 191:147–154.Google Scholar
  14. 14.
    Williamson, J. R., and Cooper, R. H. 1980. Regulation of the citric acid cycle in mammalian system. FEBS Lett. 117 (Supl):K73-K85.Google Scholar
  15. 15.
    Bunik, V. I., Buneeva, O. A., and Gomazkova, V. S. 1990. Regulation of α-ketoglutarate dehydrogenase cooperative properties in substrate binding by thiol-disulfide exchange. Biochem. Int. 21:873–881.Google Scholar
  16. 16.
    Bunik, V. I., Romash, O. G., and Gomazkova, V. S. 1990. Inactivation of α-ketoglutarate dehydrogenase during enzyme-catalyzed reaction. Biochem. Int. 22:967–976.Google Scholar
  17. 17.
    Hamada, M., Koike, K., Nakaula, Y., Hiraoka, T., Koike, M., and Hashimoto, T. 1975. A kinetic study of the α-keto acid dehydrogenase complexes from pig heart mitochondria. J. Biochem. 77:1047–1056.Google Scholar
  18. 18.
    Hilgier, W., Albrecht, J., Lisy, V., and Stastny, F. 1990. The effect of acute and repeated hyperammonemia on γ-glutamyltranspeptidase in homogenates and capillaries of various rat brain regions. Mol Chem Neuropathol. 13:47–45.Google Scholar
  19. 19.
    Norenberg, M. D. 1981. The astrocyte in liver disease. Adv. Cell. Neurobiol. 2:303–305.Google Scholar
  20. 20.
    Cooper, A. J. L., and Plum, F. 1987. Biochemistry and physiology of brain ammonia. Physiol. Rev. 67:440–519.Google Scholar
  21. 21.
    Hawkins, R. A., Miller A. L., and Nielsen, R. C. 1973. The acute action of ammonia on rat brain metabolism in vivo. Biochem. J. 134:1001–1008.Google Scholar
  22. 22.
    Albrecht, J., and Hilgier, W. 1984. Brain carbonic anhydrase activity in rats in experimental hepatogenic encephalopathy. Neurosci. Lett. 45:7–10.Google Scholar
  23. 23.
    Albrecht, J., Hilgier, W., Lazarewicz, J. W., Rafalowska, U., and Wysmyk-Cybula, U. 1988. Astrocytes in acute hepatic encephalopathy: Metabolic properties and transport functions. Pages 465–475, in Norenberg, M. D., Hertz, L., and Schousboe, A. (eds.), The Biochemical Pathology of Astrocytes, Alan R. Liss, New York.Google Scholar
  24. 24.
    Zimmermann, Ch., Ferenci, P., Pifi, Ch., Yurdaydin, C., Ebner, J., Lassmann, H., Roth, E., and Hortgnagl, H. 1989. Hepatic encephalopathy in thioacetamide induced acute liver failure in rats: Characterization of an improved model and study of amino acid-ergic neurotransmission. Hepathology: 594–601.Google Scholar
  25. 25.
    Faff-Michalak, L., and Albrecht, J. 1991. Aspartate aminotransferase, malate dehydrogenase, and pyruvate carboxylase activities in rat cerebral synaptic and nonsynaptic mitochondria: Effects of in vitro treatment with ammonia, hyperammonemia and hepatic encephalopathy. Metab. Brain Dis. 6:187–197.Google Scholar
  26. 26.
    McCormack, J. G. 1985. Evidence that adrenaline activates key oxidative enzymes in rat liver by increasing intramitochondrial [Ca2+]. FEBS Lett. 180:259–264.Google Scholar
  27. 27.
    Reed, L. J., and Willms, C. R. 1966. Purification and Resolution of the Pyruvate Dehydrogenase Complex (Escherichia coli). Pages 253–254,in Wood, W. A. (ed.), Methods in Enzymology, Vol. 9, Academic Press, New York.Google Scholar
  28. 28.
    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.Google Scholar
  29. 29.
    Zieve, L. 1987. Pathogenesis of hepatic encephalopaty. Metab. Brain Dis. 2:147–165.Google Scholar
  30. 30.
    Ferenci, P., Pappas, S. C., Munson, P. J., and Jones, E. A. 1984. Changes in glutamate receptors on synaptic membranes associated with hepatic encephalopathy or hyperammonemia in the rabbit. Hepatology 4:25–29.Google Scholar
  31. 31.
    Hilgier, W., Haugvicova, R., and Albrecht, J. 1991. Decreased potassium-stimulated release of [3H]d-aspartate from hippocampal slices distinguishes encephalopathy related to acute liver failure from that induced by simple hyperammonemia. Brain Res. 567:165–168.Google Scholar
  32. 32.
    Ratnakumari, L., and Murthy, Ch. R. K. 1990. Glucose oxidation in synaptosomes and isolated cell types in brain hyperammonemia. J. Hepatology 10 (Suppl):S21.Google Scholar
  33. 33.
    Rao, V. L. R., and Murthy, Ch. R. K. 1991. Hyperammonemic alterations in the uptake and release of glutamate and aspartate by rat cerebellar preparations. Neurosci. Lett. 130:49–52.Google Scholar
  34. 34.
    Diaz-Muñoz, M., and Tapia, R. 1989. Functional changes of brain mitochondria during experimental hepatic encephalopathy. Biochem. Pharmacol. 38:3835–3841.Google Scholar

Copyright information

© Plenum Publishing Corporation 1993

Authors and Affiliations

  • Lidia Faff-Michalak
    • 1
  • Jan Albrecht
    • 1
  1. 1.Department of Neuropathology Medical Research CenterPolish Academy of SciencesWarsawPoland

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