Skip to main content
Log in

Effects of the Antidepressant/Antipanic Drug Phenelzine on Alanine and Alanine Transaminase in Rat Brain

  • Published:
Cellular and Molecular Neurobiology Aims and scope Submit manuscript

Abstract

1. Phenelzine (PLZ) is an antidepressant with anxiolytic properties. Acute and chronic PLZ administration increase brain GABA levels, an effect due, at least in part, to an inhibition of the activity of the GABA metabolizing enzyme, GABA transaminase (GABA-T).

2. Previous preliminary reports have indicated that acute PLZ treatment also elevates brain alanine levels. As with GABA, the metabolism of alanine involves a pyridoxal phosphate-dependent transaminase.

3. In the study reported here, the effects of acute PLZ treatment on the levels of various amino acids, some of which are also metabolized by pyridoxal phosphate-dependent transaminases were compared in rat whole brain. Of the 6 amino acids investigated, only GABA and alanine levels were elevated (in a time- and dose-dependent manner).

4. The elevation in brain alanine levels could be explained, at least in part, by a time- and dose-dependent inhibitory effect of PLZ on alanine transaminase (ALA-T), although as with GABA the increases are higher than expected from the degree of enzyme inhibition produced. In addition, we also showed that the elevation in alanine levels and the inhibition of alanine transaminase in the brain are retained after 14 days of PLZ treatment, and that PLZ produces a marked increase in extracellular levels of alanine.

5. These results are discussed in terms of their relevance to synaptic function and to the pharmacological profile of PLZ.

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

REFERENCES

  • Baker, G. B., Wong, J. T. F., Yeung, J., and Coutts, R. T. (1991). Effects of the antidepressant phenelzine on brain levels of γ-aminobutyric acid. J. Affect. Disord. 21:207-211.

    Google Scholar 

  • Ballenger, J. C. (1986). Pharmacotherapy of the panic disorders. J. Clin. Psychiatry 47 (Suppl.):27-32.

    Google Scholar 

  • Chizhmakov, I. V., Kiskin, N. I., Krishtal, O. A., and Tsyndrenko, A. (1989). Glycine action on N-methyl-D-aspartate receptors in rat hippocampal neurons. Neurosci. Lett. 99:131-136.

    Google Scholar 

  • Dager, S. R., Marro, K. I., Richards, T. L., and Metzger, G. D. (1994). Preliminary application of magnetic resonance spectroscopy to investigate lactate-induced panic. Am. J. Psychiatry 151:57-63.

    Google Scholar 

  • Dager, S. R., Strauss, W. L., Marro, K. I., Richards, T. L., Metzger, G. D., and Artru, A. A. (1995). Proton magnetic resonance spectroscopy investigation of hyperventilation in subjects with panic disorder and comparison subjects. Am. J. Psychiatry 152:666-672.

    Google Scholar 

  • Erecinska, M., Nelson, D., Nissim, I., Daikhin, Y., and Yudkoff, M. (1994). Cerebral alanine transport and alanine aminotransferase reaction: Alanine as a source of neuronal glutamate. J. Neurochem. 62:1953-1964.

    Google Scholar 

  • Griebel, G., Curet, O., Perrault, G., and Sanger, D. J. (1998). Behavioral effects of phenelzine in an experimental model for screening anxiolytic and anti-panic drugs: Correlation with changes in monoamine-oxidase activity and monoamine levels. Neuropharmacology 37:927-935.

    Google Scholar 

  • Griffin, J. L., Rae, C., Dixon, R. M., Radda, G. K., and Matthews, P. M. (1998). Excitatory amino acid synthesis in hypoxic brain slices: Does alanine act as a substrate for glutamate production in hypoxia? J. Neurochem. 71:2477-2486.

    Google Scholar 

  • Hørder, M., and Rej, R. (1983). Alanine transaminase. In Bergmeyer, H. U., Bergmeyer, J., and Grassl, M. (eds.), Methods of Enzymatic Analysis, 3rd edn. Verlag-Chemie, Weinheim, pp. 444-456.

    Google Scholar 

  • Johnson, M. R., Lydiard, R. B., and Ballenger, J. C. (1995). Panic disorder: Pathophysiology and drug treatment. Drugs 49:328-344.

    Google Scholar 

  • Laake, J. H., Slyngstad, T. A., Haug, F. M., and Ottersen, O. P. (1995). Glutamine from glial cells is essential for the maintenance of the nerve terminal pool of glutamate: Immunogold evidence from hippocampal slice cultures. J. Neurochem. 65:871-881.

    Google Scholar 

  • Lai, C. T., Tanay, V. A.-M. I., Charrois, G. J. R., Baker, G. B., and Bateson, A. N. (1998). Effects of phenelzine and imipramine on the steady-state levels of mRNAs that encode glutamic acid decarboxylase (GAD67 and GAD65), the GABA transporter GAT-1 and GABA transaminase in rat cortex. Naunyn-Schmiedeberg's Arch. Pharmacol. 357:32-38.

    Google Scholar 

  • Liebowitz, M. R., Gorman, J. M., Fyer, A. J., Levitt, M., Dillon, D., Levy, G., Appleby, I. L., Anderson, S., Palij, M., Davies, S. O., Klein, D. F. (1985). Lactate provocation of panic attacks. II. Biochemical and physiological findings. Arch. Gen. Psychiatry 42:709-719.

    Google Scholar 

  • Löscher, W., and Hörstermann, D. (1994). Differential effects of vigabatrin, γ-acetylenic GABA, aminooxyacetic acid, and valproate on levels of various amino acids in rat brain regions and plasma. Naunyn-Schmiedeberg's Arch. Pharmacol. 349:270-278.

    Google Scholar 

  • Matthews, C. C., Zielke, H. R., Wollack, J. B., and Fishman, P. S. (2000). Enzymatic degradation protects neurons from glutamate excitotoxicity. J. Neurochem. 75:1045-1052.

    Google Scholar 

  • McKenna, K. F., McManus, D. J., Baker, G. B., and Coutts, R. T. (1994). Chronic administration of the antidepressant phenelzine and its N-acetyl analogue: effects on GABAergic function. J. Neural Transm. 41(Suppl.):115-122.

    Google Scholar 

  • McManus, D. J., Baker, G. B., Martin, I. L., Greenshaw, A. J., and McKenna, K. F. (1992). Effects of the antidepressant/antipanic drug phenelzine on GABA concentrations and GABA-transaminase activity in rat brain. Biochem. Pharmacol. 43:2486-2489.

    Google Scholar 

  • Parent, M. B., Bush, D., Rauw, G., Master, S., Vaccarino, F., and Baker, G. B. (2001). Analysis of amino acids and catecholamines, 5-hydroxytryptamine and their metabolites in brain areas using in vivo microdialysis. Methods 23:11-20.

    Google Scholar 

  • Parent, M. B., Habib, M. K., and Baker, G. B. (1999). Task-dependent effects of the antidepressant/antipanic drug phenelzine on memory. Psychopharmacology 142:280-288.

    Google Scholar 

  • Parent, M. B., Habib, M. K., and Baker, G. B. (2000). Time-dependent changes in brain monoamine oxidase activity and in brain levels of monoamines and amino acids following acute administration of the antidepressant/antipanic drug phenelzine. Biochem. Pharmacol. 59:1253-1263.

    Google Scholar 

  • Parent, M. B., Master, S., Kashluba, S., and Baker, G. B. (in press). The antidepressant/antipanic drug phenelzine and its putative metabolite phenylethylidenehydrazine increase extracellular GABA levels in the striatum. Biochem. Pharmacol.

  • Paslawski, T., Treit, D., Baker, G. B., George, M., and Coutts, R. T. (1996). The antidepressant drug phenelzine produces antianxiety effects in the plus-maze and increases in rat brain GABA. Psychopharmacology 127:19-24.

    Google Scholar 

  • Paslawski, T. M., Sloley, B. D., and Baker, G. B. (1995). Effects of the MAO inhibitor phenelzine on glutamine and GABA concentrations in rat brain. Prog. Brain Res. 106:181-186.

    Google Scholar 

  • Paulsen, R. E., Odden, E., and Fonnum, F. (1988). Importance of glutamine for gamma-aminobutyric acid synthesis in rat neostriatum in vivo. J. Neurochem. 51:1294-1299.

    Google Scholar 

  • Paxinos, G., and Watson, C. (1986). The Rat Brain in Stereotaxic Coordinates, Academic Press, San Diego, CA.

    Google Scholar 

  • Perry, T. L., and Hansen, S. (1973). Sustained drug-induced elevation of brain GABA in the rat. J. Neurochem. 21:1167-1175.

    Google Scholar 

  • Perry, T. L., Kish, S. J., and Hansen, S. (1979). Gamma-Vinyl GABA: Effects of chronic administration on the metabolism of GABA and other amino compounds in rat brain. J. Neurochem. 32:1641-1645.

    Google Scholar 

  • Phillis, J. W., Ren, J., and O'Regan, M. H. (2000). Transporter reversal as a mechanism of glutamate release from the ischemic rat cerebral cortex: Studies with DL-threo-beta-benzyloxyaspartate. Brain Res. 868:105-112.

    Google Scholar 

  • Pitts, F. N., Jr., and McClure, J. N., Jr. (1967). Lactate metabolism in anxiety neurosis. N. Engl. J. Med. 277:1329-1336.

    Google Scholar 

  • Popov, N., and Matthies, H. (1969). Some effects of monoamine oxidase inhibitors on the metabolism of γ-aminobutyric acid in rat brain. J. Neurochem. 16:899-907.

    Google Scholar 

  • Preece, N. E., and Cerdan, S. (1996). Metabolic precursors and compartmentation of cerebral GABA in vigabatrin-treated rats. J. Neurochem. 67:1718-1725.

    Google Scholar 

  • Sterri, S. H., and Fonnum, F. (1978). Isolation of organic anions by extraction with liquid anion exchangers and its application to micromethods for acetylcholinesterase and 4-aminobutyrate aminotransferase. Eur. J. Biochem. 91:215-222.

    Google Scholar 

  • Tate, S. S., and Meister, A. (1971). Regulation of rat liver glutamine synthetase: Activation by alpha-ketoglutarate and inhibition by glycine, alanine, and carbamyl phosphate. Proc. Natl. Acad. Sci. U.S.A. 68:781-785.

    Google Scholar 

  • Timmerman, W., and Westerink, B. H. (1997). Brain microdialysis of GABA and glutamate: What does it signify? Synapse 27:242-261.

    Google Scholar 

  • Waagepetersen, H. S., Sonnewald, U., Larsson, O. M., and Schousboe, A. (2000). A possible role of alanine for ammonia transfer between astrocytes and glutamatergic neurons. J. Neurochem. 75:471-479.

    Google Scholar 

  • Wong, J. T., Baker, G. B., Coutts, R. T., and Dewhurst, W. G. (1990a). Long-lasting elevation of alanine in brain produced by the antidepressant phenelzine. Brain Res. Bull. 25:179-181.

    Google Scholar 

  • Wong, J. T. F., Baker, G. B., and Coutts, R. T. (1990b). A rapid, sensitive assay for γ-aminobutyric acid in brain using electron-capture gas chromatography. Res. Commun. Chem. Pathol. Pharmacol. 70:115-124.

    Google Scholar 

  • Yudkoff, M., Nissim, I., and Hertz, L. (1990). Precursors of glutamic acid nitrogen in primary neuronal cultures: Studies with 15N. Neurochem. Res. 15:1191-1196.

    Google Scholar 

  • Yudkoff, M., Nissim, I., Hummeler, K., Medow, M., and Pleasure, D. (1986). Utilization of [15N]glutamate by cultured astrocytes. Biochem. J. 234:185-192.

    Google Scholar 

  • Yudkoff, M., Nissim, I., and Pleasure, D. (1988). Astrocyte metabolism of [15N]glutamine: Implications for the glutamine-glutamate cycle. J. Neurochem. 51:843-850.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Tanay, V.AM.I., Parent, M.B., Wong, J.T.F. et al. Effects of the Antidepressant/Antipanic Drug Phenelzine on Alanine and Alanine Transaminase in Rat Brain. Cell Mol Neurobiol 21, 325–339 (2001). https://doi.org/10.1023/A:1012697904299

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/A:1012697904299

Navigation