Summary
The in vivo rate of brain tryptophan hydroxylation was determined through 5-hydroxytryptophan accumulation (5-HTPacc) following the administration of NSD 1015, a L-aromatic amino-acid decarboxylase inhibitor. This measurement was performed every 4 h throughout a 24 h hour period in 10 discrete brain areas of rats maintained on a regular 12 h/12 h light-dark cycle. The concentrations of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) were also determined in untreated rats. Daily variations in 5-HTPacc were found in all the areas studied, the 5-HTPacc being higher during the dark period in most structures. These results strongly suggest that tryptophan hydroxylation is involved in the control of the 5-HT biosynthesis circadian rhythm. However, various patterns of 5-HT and 5-HIAA daily variations were observed, suggesting that the circadian factors affecting serotonin metabolism can be different among brain areas.
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Agren H, Koulu M, Saavedra JM, Potter WZ, Linnoila M (1986) Circadian covariations of norepinephrine and serotonin in the locus coeruleus and dorsal raphe nucleus in the rat. Brain Res 397: 353–358
Azmitia EC, Segal M (1978) An autoradiographic analysis of the differential ascending projections of the dorsal and median raphe nuclei in the rat. J Comp Neurol 179: 641–668
Banky Z, Molnar J, Csernus V, Halasz B (1988) Further studies on circadian hormone rhythms after local pharmacological destruction of the serotoninergic innervation of the rat suprachiasmatic region before the onset of the corticosterone rhythm. Brain Res 445: 222–227
Blier P, Galzin AM, Langer SZ (1989) Diurnal variation in the function of serotonin terminals in the rat hypothalamus. J Neurochem 52: 453–459
Boadle-Biber MC, Johannessen JN, Narasimhachari N, Phan TH (1983) Activation of tryptophan hydroxylase by stimulation of central serotonergic neurons. Biochem Pharmacol 32: 185–188
Bourgoin S, Oliveras JL, Bruxelle J, Hamon M, Besson JM (1980) Electrical stimulation of the nucleus raphe magnus in the rat. Effects on 5-HT metabolism in the spinal cord. Brain Res 194: 377–389
Bradford MM (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
Brown F, Nicholass J, Redfern PH (1982) Synaptosomal tryptophan-hydroxylase activity in rat brain measured over 24-hours. Neurochem Int 4: 181–183
Cahill AL, Ehret CF (1981) Circadian variations in the activity of tyrosine hydroxylase, tyrosine aminotransferase and tryptophan hydroxylase: relationship to catecholamine metabolism. J Neurochem 37: 1109–1115
Carlsson A, Davis JN, Kehr W, Lindqvist M, Atack CV (1972) Simultaneous measurement of tyrosine and tryptophan hydroxylase activities in brain in vivo using an inhibitor of the aromatic amino acid decarboxylase. Naunyn Schmiedebergs Arch Pharmacol 275: 153–168
Cespuglio R, Sarda N, Gharib A, Chastrette N, Houdoin F, Rampin C, Jouvet M (1990) Voltammetric detection of the release of 5-hydroxyindole compounds throughout the sleep-waking cycle of the rat. Exp Brain Res 80: 121–128
Chevillard C, Barden N, Saavedra JM (1981) Twenty-four hour rhythm in monoamine oxidase activity in specific areas of the rat brain stem. Brain Res 223: 205–209
DiRaddo J, Kellogg C (1975) In vivo rates of tyrosine and tryptophan hydroxylation in regions of rat brain at four times during the light dark cycle. Naunyn Schmiedebergs Arch Pharmacol 286: 389–400
Duda NJ, Moore KE (1985) Simultaneous determination of 5-hydroxytryptophan and 3,4-dihydroxyphenylalanine in rat brain by HPLC with electrochemical detection following electrical stimulation of the dorsal raphe nucleus. J Neurochem 44: 128–133
Faradji H, Cespuglio R, Jouvet M (1983) Voltammetric measurements of 5-hydroxyindole compounds in the suprachiasmatic nuclei. Circadian fluctuations. Brain Res 279: 111–119
Halberg F, Tong YL, Johnson EA (1967) Circadian system phase, an aspect of temporal morphology: procedures and illustrative examples. In: Von Mayerbash H (ed) Cellular aspects of biorhythms. Springer, Berlin Heidelberg New York, pp 20–48
Hamon M, Glowinski J (1974) Regulation of serotonin synthesis. Life Sci 15: 1533–1548
Héry F, Rouer E, Glowinski J (1972) Daily variations of serotonin metabolism in the rat brain. Brain Res 43: 445–465
Héry F, Chouvet G, Kan JP, Pujol JF, Glowinski J (1977) Daily variations of various parameters of serotonin metabolism in the rat brain. II. Circadian variations in serum and cerebral tryptophan levels: lack of correlation with 5-HT turnover. Brain Res 123: 137–145
Kan JP, Chouvet G, Héry F, Debilly G, Mermet A, Glowinski J, Pujol JF (1977) Daily variations of various parameters of serotonin metabolism in the rat brain. I. Circadian variations of tryptophan-5-hydroxylase in the raphe nuclei and the striatum. Brain Res 123: 125–136
Levine JD, Rosenwasser AM, Yanovski JA, Adler NT (1986) Circadian activity rhythms in rats with midbrain raphe lesions. Brain Res 384: 240–249
Loizou G, Redfern PH (1986) Circadian variation in uptake of tryptophan by synaptosomes from the rat cortex. J Pharm Pharmacol 38: 89 P
Louis-Coindet J (1980) Rythmes de sommeil du rat mâle: mise en évidence des structures impliquées dans les mécanismes d'organisation des états de vigilance. Thesis, Université Claude-Bernard, Lyon
Martin KF (1991) Rhythms in neurotransmitter turnover: focus on the serotonergic system. Pharmacol Ther 51: 421–429
McLennan IS, Lees GJ (1978) Diurnal changes in the kinetic properties of tryptophan hydroxylase from rat brain. J Neurochem 31: 557–559
Medanic M, Gillette MU (1992) Serotonin regulates the phase of the rat suprachiasmatic circadian pacemaker in vitro only during the subjective day. J Physiol 450: 629–642
Meek JL, Lofstrandh S (1976) Tryptophan hydroxylase in discrete brain nuclei: comparison of activity in vitro and in vivo. Eur J Pharmacol 37: 377–380
Meijer JH, Rietveld WJ (1989) Neurophysiology of the suprachiasmatic circadian pacemaker in rodents. Physiol Rev 69: 671–707
Meyer DC, Quay WB (1976) Hypothalamic and suprachiasmatic uptake of serotonin in vitro: twenty-four-hour changes in male and proestrous female rats. Endocrinology 98: 1160–1165
Moore RY, Halaris AE, Jones BE (1978) Serotonin neurons of the midbrain raphe: ascending projections. J Comp Neurol 180: 417–438
Morgan WW, Saldana JJ, Yndo CA, Morgan JF (1975) Correlations between circadian changes in serum amino acids or brain tryptophan and the contents of serotonin and 5-hyroxyindoleacetic acid in regions of the rat brain. Brain Res 84: 75–86
Morin A, Denoroy L, Jouvet M (1991) Daily variations in concentration of vasoactive intestinal polypeptide immunoreactivity in discrete brain areas of the rat. Brain Res 538: 136–140
Prosser RA, Miller JD, Heller HC (1990) A serotonin agonist phase-shifts the circadian clock in the suprachiasmatic nuclei in vitro. Brain Res 534: 336–339
Quay WB (1968) Differences in circadian rhythms in 5-hydroxytryptamine according to brain region. Am J Physiol 215: 1448–1453
Ramirez AD, Ramirez VD, Meyer DC (1987) The nature and magnitude of in vivo 5-hydroxyindoleacetic acid output from 5-hydroxytryptamine terminals is related to specific regions of the suprachiasmatic nucleus. Neuroendocrinology 46: 430–438
Smale L, Michels KM, Moore RY, Morin LP (1990) Destruction of the hamster serotonergic system by 5,7-DHT: effects on circadian rhythm phase, entrainment and response to triazolam. Brain Res 515: 9–19
Szafarczyk A, Ixart G, Alonso G, Malaval F, Nouguier-Soule L, Assenmacher I (1981) Effects of raphe lesions on circadian ACTH, corticosterone and motor activity rhythms in free-running blinded rats. Neurosci Lett 23: 87–92
Tappaz ML, Pujol JF (1980) Estimation of the rate of tryptophan hydroxylation in vivo: a sensitive microassay in discrete rat brain nuclei. J Neurochem 34: 933–940
Van De Kar LD, Lorens SA (1979) Differential serotonergic innervation of individual hypothalamic nuclei and other forebrain regions by the dorsal and median midbrain raphe nuclei. Brain Res 162: 45–54
Wirz-Justice A, Kräuchi K, Morimasa T, Willener R, Feer H (1983) Circadian rhythm of [3H]imipramine binding in the rat suprachiasmatic nuclei. Eur J Pharmacol 87: 331–333
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Poncet, L., Denoroy, L. & Jouvet, M. Daily variations in in vivo tryptophan hydroxylation and in the contents of serotonin and 5-hydroxyindoleacetic acid in discrete brain areas of the rat. J. Neural Transmission 92, 137–150 (1993). https://doi.org/10.1007/BF01244873
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DOI: https://doi.org/10.1007/BF01244873