Fish Physiology and Biochemistry

, Volume 15, Issue 1, pp 41–48 | Cite as

Tyrosine hydroxylase activity and dopamine turnover of rainbow trout (Oncorhynchus mykiss) brain: the special status of the hypothalamus

  • Boris Linard
  • Sanae Bennani
  • Patrick Jego
  • Christian Saligaut


The dynamics of catecholamine (CA)-synthesis enzymes have been poorly studied in fish. Tyrosine hydroxylase (TH), the rate-limiting enzyme of CA synthesis has been only studied inin vitro conditions. In the present report thein vivo CA synthesis and the CA metabolism were studied in different regions of the forebrain of the rainbow trout. Levels of norepinephrine (NE), dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) and the rate of accumulation of 3,4-dihydroxyphenylalanine (DOPA) were determined by HPLC following a treatment with hydroxybenzylhydrazine (NSD), a potential inhibitor of DOPA decarboxylase. Kinetics of the accumulation of DOPA and of the decline of DOPAC were in agreement with those found in rat, evidencing that the accumulation of DOPA following NSD can be used in trout to quantify thein vivo enzymatic activity of tyrosine hydroxylase. Experiments using treatment with NSD or with methyl-p-tyrosine reached a same conclusion: the DA neuronal activity in trout is much higher than NE neuronal activity. However, the hypothalamus had high DA levelsvs. lowin vitro andin vivo TH activities and exhibited a low CA turnover.


trout dopamine norepinephrine tyrosine hydroxylase olfactory bulbs hypothalamus preoptic area telencephalon 


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References cited

  1. Batten, T.F.C., Berry, P.A., Maqbool, A., Moons, L. and Vandesande, F. 1993. Immunolocalization of catecholamine enzymes, serotonin, dopamine and L-dopa in the brain ofDicentrachus labrax (Teleostei). Brain Res. Bull. 31: 233–252.Google Scholar
  2. Beltramo, M., Krieger, M., Tillet, Y., Thibault, J., Calas, A., Mazzi, V. and Franzoni, M.F. 1994. Immunolocalization of aromatic L-amino acid decarboxylase in goldfish (Carassius auratus) brain. J. Comp. Neurol. 343: 209–227.Google Scholar
  3. Bradford, M. 1976. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal. Biochem. 72: 248–254.Google Scholar
  4. Demarest, K.T. and Moore, K.E. 1980. Accumulation of L-DOPA in the median eminence: an index of tuberoinfundibular dopaminergic nerve activity. Endocrinology 106: 463–468.Google Scholar
  5. Dulka, J.G., Sloley, B.D., Stacey, N.E. and Peter, R.E. 1992. A reduction in pituitary dopamine turnover in associated with sex pheromone-induced gonadotropin secretion in male goldfish. Gen. Comp. Endocrinol. 86: 496–505.Google Scholar
  6. Ekström, P., Honkanen, T. and Steinbusch, H.W.M. 1990. Distribution of dopamine-immunoreactive neuronal perikarya and fibres in the brain of a teleost,Gasterosteus aculeatus L. Comparison with tyrosine hydroxylase and dopamine-β-hydroxylase-immunoreactive neurons. J. Chem. Neuroanat. 3: 233–260.Google Scholar
  7. Gonzalez, H.A., Kedzierski, W. and Porter, J.C. 1988. Mass and activity of tyrosine hydroxylase in tuberoinfundibular dopaminergic neurons of the aged brain. Neuroendocrinology 48: 663–667.Google Scholar
  8. Gonzalez, H.A. and Porter J.C. 1988. Mass andin situ activity of tyrosine hydroxylase in the median eminence: effect of hyperprolactinemia. Endocrinology 122: 2272–2277.Google Scholar
  9. Joh, T.H., Park, D.H. and Reis, D.J. 1978. Direct phosphorylation of brain tyrosine hydroxylase by cyclic AMP-dependent protein kinase: mechanism of enzyme activation. Proc. Natl. Acad. Sci. U.S.A. 75: 4744–4748.Google Scholar
  10. Labatut, R., Richard, F., Milne, B., Quintin, L., Lecestre, D. and Pujol, J.F. 1988. Long-term effects of RU24722 on tyrosine hydroxylase of the rat brain. J. Neurochem. 51: 1367–1374.Google Scholar
  11. Le Bras, Y.M. 1984. Circadian variations of catecholamine levels in brain, heart and plasma in the eel,Anguilla anguilla L., at three different times of year. Gen. Comp. Endocrinol. 55: 472–479.Google Scholar
  12. Levitt, M., Spector, S., Sjoerdoma, A. and Udenfriend, S. 1965. Elucidation of the rate-limiting step in norepinephrine biosynthesis in the perfused guinea-pig heart. J. Pharmacol. Exp. Ther. 148: 1–7.Google Scholar
  13. Lloyd, T. and Weisz, J. 1978. Direct inhibition of tyrosine hydroxylase activity by catechol estrogens. J. Biol. Chem. 253: 4841–4843.Google Scholar
  14. Meek, J., Joosten, H.W.J. and Steinbusch, H.W.M. 1989. Distribution of dopamine immunoreactivity in the brain of the Mormyrid teleostGnathonemus petersii. J. Comp. Neurol. 281: 362–383.Google Scholar
  15. Meek, J. and Joosten, H.W.J. 1993. Tyrosine hydroxylase-immunoreactive cell groups in the brain of the teleost fish,Gnathonemus petersii. J. Chem. Neuroanat. 6: 431–446.Google Scholar
  16. Nagatsu, T., Oka, K. and Kato, T. 1979. Highly sensitive assay for tyrosine hydroxylase activity by high-performance liquid chromatography. J. Chromatogr. 163: 247–252.Google Scholar
  17. Nilsson, G.E. 1989. Regional distribution of monoamines and monoamine metabolites in the brain of the crucian carp (Carassius carassius L.). Comp. Biochem. Physiol. 94: 223–228.Google Scholar
  18. Popek, W. 1983. Seasonal variations in circadian rhythm of hypothalamic catecholamine content in the eel (Anguilla anguilla). Comp. Physiol. Biochem. 75: 193–198.Google Scholar
  19. Reymond, M.J. and Porter, J.C. 1982. Hypothalamic secretion of dopamine after inhibition of aromatic L-amino acid decarboxylase activity. Endocrinology 111: 1051–1056.Google Scholar
  20. Roberts, B.L., Meredith, G.E. and Maslam, S. 1989. Immunocytochemical analysis of the dopamine system in the brain and spinal cord of the European eel,Anguilla anguilla. Anat. Embryol. 180: 401–412.Google Scholar
  21. Saligaut, C., Bailhache, T., Salbert, G., Breton, B. and Jego, P. 1990. Dynamic characteristics of serotonin and dopamine metabolism in the rainbow trout brain: a regional study using liquid chromatography with electrochemical detection. Fish Physiol. Biochem. 8: 199–205.Google Scholar
  22. Saligaut, C., Salbert, G., Bailhache, T., Bennani, S. and Jego, P. 1992a. Serotonin and dopamine turnover in the female rainbow trout (Oncorhynchus mykiss) brain and pituitary: changes during the annual reproductive cycle. Gen. Comp. Endocrinol. 85: 261–268.Google Scholar
  23. Saligaut, C., Garnier, D.H., Bennani, S., Salbert, G., Baihache, T. and Jego, P. 1992b. Effecs of estradiol on brain aminergic turnover of the female rainbow trout (Oncorhynchus mykiss) at the beginning of vitellogenesis. Gen. Comp. Endocrinol. 88: 209–216.Google Scholar
  24. Saligaut, C., Bennani, S. and Bailhache, T. 1993. Catecholamine synthesis in the rainbow trout (Oncorhynchus mykiss) brain: modulation of tyrosine hydroxylase activity. Fish Physiol. Biochem. 11: 139–144.Google Scholar
  25. Sas, E., Maler, L. and Tinner, B. 1990. Catecholaminergic systems in the brain of a gymnotiform teleost fish: an immunohistochemical study. J. Comp. Neurol. 292: 127–162.Google Scholar
  26. Senthilkumaran, B. and Joy, K.P. 1995. Changes in hypothalamic catecholamines, dopamine-β-hydroxylase, and phenylethanolamine-N-methyltransferase in the catfishHeteropneustes fossilis in relation to season, raised photoperiod and temperature, ovariectomy, and estradiol-17-β replacement. Gen. Comp. Endocrinol. 97: 121–134.Google Scholar
  27. Trudeau, V.L., Sloley, B.D., Wong, A.O.L. and Peter, R.E. 1993. Interactions of gonadal steroids with brain dopamine and gonadotropin-releasing hormone in the control of gonadotropin-II secretion in the goldfish. Gen. Comp. Endocrinol. 89: 39–50.Google Scholar
  28. Zigmond, E.R., Schwarzschild, M.A. and Rittenhouse, A.R. 1989. Acute regulation of tyrosine hydroxylase by nerve activity and by neurotransmitters via phosphorylation. Ann. Rev. Neurosci. 12: 415–461.Google Scholar

Copyright information

© Kugler Publication bv 1996

Authors and Affiliations

  • Boris Linard
    • 1
  • Sanae Bennani
    • 1
  • Patrick Jego
    • 1
  • Christian Saligaut
    • 1
  1. 1.Laboratoire de Physiologie des Régulations, U.R.A. CNRS 256, Equipe associée d'Endocrinologie Moléculaire des PoissonsINRA/Université de Rennes IRennes cedexFrance

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