Modulatory Effects of L- Tyrosine on Neurobehavioural Consequences of Combat Stress in Rats
Abstract
The paper presents the results of a study conducted to elucidate tile potentiality of tyrosine, aprecursor of catecholaminergic neurotransmitters, against combat stress-associated behavioural changes and brain catecholamine status in an animal model. The results obtained showed that stressimpaired the performance on Morris water maze (MWM) in saline-injected rats and concurrentlylowered norepinephrine (NE) levels in brain. This could be due to decreased dopamine J3-hydroxylase(DBH) activity and increased monoamine oxidase (MAO) activity. On the contrary, there was asignificant improvement in post-stress performance in MWM test in animals receiving tyrosine.Stress-induced increase in catecholamine metabolites, homovanillic acid and vanillylmandelic acid inbrain was prevented by treatment with tyrosine. The present fmdings imply that precursor availabilitycould be a limiting factor to sustain intensified catecholamine synthesis during stress and hencesupplementation of L-tyrosine could be beneficial to improve performance during stressReferences
Haubrich, D.R. & Denzer, J. S. Simultaneous extraction and fluorometric measurment of
brain serotonin, catecholamines, 5 -hydroxyindoleacetic acid and homovanillic acid.
Analytical Biochemistry., 1973,55,306-12.
Pisano, 1.1. & Crout, D.A. Detennination of 4-hydroxy-3-methoxymandelic acid in urine.
Clin. Chim. Acta., 1962,7, 285-89.
Nagatsu, T. & Udenfriend, S. Photometeric assay of dopamine-f3-hydroxylase activity in human blood. Clinical. Chemistry, 1972,18,980-83.
Ono, T.; Eto, K.; Sakata, Y. & Takeda, M. A new colorimetric assay for monoamine oxidase in
serum and its clinical application. .1: Lab. Clin.Med., 1975,85,1022-31.
Bliss, E.L. ; Ailion, J. & Zwanziger, J . Metabolism of norepinephrine, serotonin and dopamine in rat brain with stress. .1: Pharmacal. 'Exp. Ther., 1968,164, 122-25.
Corrodi, H.; Fuxe, K. & Hokfelt, T. The effect of immobilisation stress on the activity of central monoamine neurons-. Life Science, 1968, 7, 107-12.
Lehnert, H.; Reinstein, D.K.; Benjamin, W.S. & Wurtman, R.J. Neurochemical and behavioural consequences of acute, uncontrollable stress. Effect of dietary tyrosine. Brain, 1984, 303, 215-23.
Saito, H.; Morita, A.; Miyazaki, I. & Takagi, K. Comparison of the effects of various stresses on biogenic amines in the central nervous system and animal symptoms. Catecholamines and stress, edited by E. Usdin, R. Kvetnansky, & 1.1. Kopin, Pergamon Press, Oxford. pp.95-103.
Roth, K.A.; Mefford, I.A. & Barchas, J.D. Epinephrine, norepinephrine, dopamine and serotonin: Differential effects of acute and chronic stress on regional brain amines. Brain,
, 239,417-20.
Rauch, T.M. & Lieberman, H.R. Tyrosine pretreatment reverses hypothermia-induced
behavioural depression. Brain Res. Bull., 1990, 24, 147-50.
Liebennan, H.R.; Shukitt-Hale, B.; Luo, S.; Devine, J. A. & Glenn, J .f .Tyrosine reduces the
adverse effect of hypobaric hypoxia on spatial working memory of the rat. Sac. Neurosci, Abstr.,1992,18,715.
Okada, A.; Arizumi, M. & Okamoto, G. Changes in cerebral norepinephrine-induced by vibration or noise stress. Eur. J. Appl. Physial., 1983, 52, 94-97.
Maynert, E. W .& Levi, R. Stress-induced release of brain norepinephrine and its inhibition by drugs. J. Pharmacal. Exp. Ther., 1964, 143,90-95.
Swenson, R.M. & Voget, W .H. Plasma catecholamine and corticosterone as well as brain
catecholamine changes during coping in rats exposed to stressful footshock. Pharmacal;
Biachem. Behav., 1982,18 (5),689-93.
Curzon, G.; Joseph, M.H. & Knott. P.J. Effects of imrnQbilisation and food deprivation on rat brain tryptophan metabolism. Journal of Neurochemistry, 1972,19, 1967-74.
Matlina, E. Sh. Main phases of catecholamine metabolism under stress. In Catecholamines and stress, edited by E. Usdin, R. Kvetnansky & I.J. Kopin, Pergamon Press, Oxford, 1976.
pp.353-65.
Lieberman, H.R. In Food components to enhance performance edited by B.M. Marriott, National Academy Press, Washington, DC., 1994. pp. 277- 82
Banderet, L.E. & Lieberman, H.R. Treatment with tyrosine, a neurotransmitter precursor ,
reduces environmental stress in humans. Brain Res. Bull., 1989,22,759-62.
Owasoyo, J.O.; Neri, D.F. & Lamberth, J.G. Tyrosine and its potential use as a countermeasure to performance decrement in military sustained operations. Aviat. Space Environ. Med.. 1992,63, 364-69.
Where otherwise noted, the Articles on this site are licensed under Creative Commons License: CC Attribution-Noncommercial-No Derivative Works 2.5 India