Day–night rhythm of 5-methoxytryptamine biosynthesis in the pineal gland of the golden hamster (Mesocricetus auratus)

Galzin, Anne-Marie; Eon, M.T.; Esnaud, H.; Lee, C. R.; Pévet, Paul; Langer, S. Z.

doi:10.1677/joe.0.1180389

Cited by 36 publications

(29 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The first problem concerns the fast destruction of 5-MT by MAO A. Contrary to melatonin and NAS, the non-acetylated indoleamines in general and 5-MT in particular represent rapidly converted substrates of MAO A [28,46]. Reliable 5-MT measurements in the pineal gland require the presence of MAO inhibitors [28,101].…”

Section: Melatonin Deacetylationmentioning

confidence: 99%

Melatonin Metabolism in the Central Nervous System

Hardeland¹

2010

114

110

View full text Add to dashboard Cite

Abstract:The metabolism of melatonin in the central nervous system is of interest for several reasons. Melatonin enters the brain either via the pineal recess or by uptake from the blood. It has been assumed to be also formed in some brain areas. Neuroprotection by melatonin has been demonstrated in numerous model systems, and various attempts have been undertaken to counteract neurodegeneration by melatonin treatment. Several concurrent pathways lead to different products. Cytochrome P 450 subforms have been demonstrated in the brain. They either demethylate melatonin to Nacetylserotonin, or produce 6-hydroxymelatonin, which is mostly sulfated already in the CNS. Melatonin is deacetylated, at least in pineal gland and retina, to 5-methoxytryptamine. N 1 -acetyl-N 2 -formyl-5-methoxykynuramine is formed by pyrrole-ring cleavage, by myeloperoxidase, indoleamine 2,3-dioxygenase and various non-enzymatic oxidants. Its product, N 1 -acetyl-5-methoxykynuramine, is of interest as a scavenger of reactive oxygen and nitrogen species, mitochondrial modulator, downregulator of cyclooxygenase-2, inhibitor of cyclooxygenase, neuronal and inducible NO synthases. Contrary to other nitrosated aromates, the nitrosated kynuramine metabolite, 3-acetamidomethyl-6-methoxycinnolinone, does not re-donate NO. Various other products are formed from melatonin and its metabolites by interaction with reactive oxygen and nitrogen species. The relative contribution of the various pathways to melatonin catabolism seems to be influenced by microglia activation, oxidative stress and brain levels of melatonin, which may be strongly changed in experiments on neuroprotection. Many of the melatonin metabolites, which may appear in elevated concentrations after melatonin administration, possess biological or pharmacological properties, including N-acetylserotonin, 5-methoxytryptamine and some of its derivatives, and especially the 5-methoxylated kynuramines.

show abstract

Section: Melatonin Deacetylationmentioning

confidence: 99%

Melatonin Metabolism in the Central Nervous System

Hardeland¹

2010

114

110

View full text Add to dashboard Cite

show abstract

“…Food pellets and tap water were provided ad libitum. 5-methoxytryptamine is only detectable in the pineal gland of golden hamsters after inhibition of monoamine oxidase (Galzin et al, 1988). Consequently, after eight weeks of exposure to these different photoperiods, the animals received at 16.00h on day one an intraperitoneal injection of 100mg/kg pargyline, an inhibitor of monoamine oxidase (MAOI).…”

Section: Animalsmentioning

confidence: 99%

“…A rhythmic synthesis of 5-MT has been shown in the pineal gland of golden hamsters following pargyline administration, higher values being observed during the light period (Galzin et al, 1988). The aim of this study was to determine if the rhythmic secretion of 5-MT depends upon the photoperiodic regime.…”

Section: Introductionmentioning

confidence: 97%

Effect of different photoperiods on the diurnal rhythm of 5-methoxytryptamine in the pineal gland of golden hamsters (Mesocricetus auratus)

Raynaud

Pévet

1991

J. Neural Transmission

View full text Add to dashboard Cite

This study tested the photo-dependency of the rhythmic synthesis of 5-methoxytryptamine (5-MT) in the pineal gland of golden hamsters. After pargyline administration, pineal 5-methoxytryptamine and melatonin were measured by HPLC in male golden hamsters kept under short and long photoperiod. In both photoperiodic regimes, a clear 5-MT rhythm was observed which fitted a sinusoidal function with high values occurring during the daytime and low values occurring during the night-time. The duration of the low night-time levels was clearly proportional to the length of the dark phase. A marked rhythm of melatonin synthesis was also seen with low daytime levels and high night-time values. An inverse relationship between 5-MT and melatonin levels was observed. Thus, after pargyline administration, the rhythms of 5-MT and melatonin in the pineal gland of golden hamsters are photoperiod-dependent and show a reciprocal relationship.

show abstract

“…Experimentally it has also been observed that 8 weeks of exposure to SP induces a complete gonadal and accessory sex organ atrophy (Masson-P6vet et al, 1987 (Steinlechner et al, 1983 ;Quay, 1963), 5-methoxytryptophol (Beck and P6vet, 1984 ;Skene et al, 1987 ;Mefford et al, 1983), 5-methoxytryptamine (Galzin et al, 1988) and melatonin (for references see Reiter, 1980). The physiological properties of most of these putative pineal hormones are yet poorly defined but on one of them, melatonin, extensive studies have been performed and it is now generally accepted that this hormone is responsible for the mediation of the effects of the pineal.…”

mentioning

confidence: 99%

“…5-methoxytryptamine, one of the 5-methoxyindoles (including melatonin) synthesized in the pineal gland (P6vet, 1983 ;Galzin et al, 1988) is a very potent serotonin (5-HT) autoreceptor agonist inhibiting, in a concentration dependent manner, the electrically evoked release of 3 H-5-HT from superfused rat hypothalamic slices (Galzin and Langer, 1986). This potent effect of 5-methoxytryptamine on the serotoninergic neurotransmission, although not yet fully evaluated, is probably of physiological importance.…”

mentioning

confidence: 99%