Iodinated melatonin: Preparation and characterization of the molecular structure by mass and 1H NMR spectroscopy

Vakkuri, Olli; Lämsä, E.; Rahkamaa, Erkki; Ruotsalainen, Heikki; Leppäluoto, Juhani

doi:10.1016/0003-2697(84)90466-4

Cited by 182 publications

(81 citation statements)

References 21 publications

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“…[2-'2SI]lodomelatonin ("'I-melatonin) was prepared by iodination of melatonin (Sigma) with NalZ51 (Amersham) [17]. Aliquots of the synaptosomal preparations (50/g protein/20@1) were incubated with 40~1 Tris buffer containing 20-100 nM '251-melatonin (20 Ci/mmol) for 30 min at 37°C in a shaking water bath, in the absence or presence of unlabeled melatonin (50 /cM).…”

Section: Methodsmentioning

confidence: 99%

Circadian variations in melatonin‐binding sites in discrete areas of the male rat brain

Zisapel

Nir²,

Laudon

1988

FEBS Letters

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The binding of lZSI-melatonin to synaptosomes prepared from whole brains of male rats of the CD strain and from the brain, hypothalamus and striatum of male rats of the Sabra-Wistar strain was assessed throughout a 24 h period. The animals were maintained under a daily schedule of 14 h light (05:0&19:00 h) and 10 h darkness. In whole brain preparations the density of binding sites at 1890 h was higher by about 70% than at 02%~ h with no variations in apparent affinity of the binding sites throughout the daily period. Specific binding of iZSI-melatonin was found in both hypothalamus and striatum of the male rat with a distinct diurnal variation in binding site density in the hypothalamus only. The density of 12sI-melatonin-binding sites in the hypothalamus was maximal between 1O:OO and 18:00 h and dropped sharply after the lights went off. The apparent lZSI-melatonin-binding affinities in these regions were constant and very similar to those in whole brain preparations. The daily variations in densities of '251-melatonin-binding sites in discrete brain areas may represent a diurnal rhythmicity in the responsiveness of the neuroendocrine axis to melatonin.

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Section: Methodsmentioning

confidence: 99%

Circadian variations in melatonin‐binding sites in discrete areas of the male rat brain

Zisapel

Nir²,

Laudon

1988

FEBS Letters

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“…Melatonin, acting via a presynaptic heteroreceptor, inhibits retinal dopamine release, and this bioassay was used to establish the relative order of potency for a series of agonists and putative antagonists as well as to discover the first competitive melatonin antagonist, luzindole (Dubocovich, 1988a,c). Vakkuri et al (1984) introduced the radioligand 2-[ 125 I]iodomelatonin as a tracer for use in melatonin radioimmunoassays. This molecule turned out to be the silver bullet of melatonin receptor research in that its selectivity and high specific activity allowed the field to move forward.…”

Section: B Melatonin Receptor Discovery: Historical Backgroundmentioning

confidence: 99%

International Union of Basic and Clinical Pharmacology. LXXV. Nomenclature, Classification, and Pharmacology of G Protein-Coupled Melatonin Receptors

Dubocovich

Delagrange

Krause

et al. 2010

Pharmacological Reviews

535

510

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“…Recent studies using 2-[1251]-iodomelatonin, a ligand originally developed for use in aMT radioimmunoassay (Vakkuri et al, 1984), identified and characterized specific, high affinity receptors which probably mediate at least some of these actions of melatonin (Krause & Dubocovich, 1991;Morgan et al, 1994). Our studies on the high affinity 2-[125I]_ iodomelatonin binding sites found in several tissues (brain, pars tuberalis and retina) and species (sheep, chicken and wallaby) using a series of novel melatonin analogues have indicated a considerable similarity of melatonin receptor characteristics (Sugden & Chong, 1991;Paterson et al, 1992).…”

Section: Introductionmentioning

confidence: 99%

Structural requirements at the melatonin receptor

Sugden

Chong

Lewis

1995

British J Pharmacology

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1 High affinity, specific binding sites for the pineal hormone, melatonin (5-methoxy Nacetyltryptamine) can be detected in chick brain membranes by use of the radiolabelled agonist,2 The affinity of a number of analogues of melatonin at the 2-[1251I]-aMT binding site was determined and compared with an analysis of their electronic structure and significant quantitative relationships obtained. 3 The best correlations indicated that binding affinity was correlated with AE, the difference between the frontier orbital energies, and QNH, the electron density in the highest occupied molecular orbital of the side-chain nitrogen atom. 4 These findings suggest that ligand binding may involve hydrogen bonding between the 5-methoxy and amide moieties of melatonin and complementary amino acid residues, and charge transfer interactions between the indole ring of melatonin and an aromatic amino acid in the receptor binding site. 5 A molecular model of a putative binding site is proposed based on the predicted amino acid sequence of the cloned Xenopus laevis melanophore melatonin receptor and the quantitative structureaffinity relationships observed in the present study.

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Iodinated melatonin: Preparation and characterization of the molecular structure by mass and 1H NMR spectroscopy

Cited by 182 publications

References 21 publications

Circadian variations in melatonin‐binding sites in discrete areas of the male rat brain

Circadian variations in melatonin‐binding sites in discrete areas of the male rat brain

International Union of Basic and Clinical Pharmacology. LXXV. Nomenclature, Classification, and Pharmacology of G Protein-Coupled Melatonin Receptors

Structural requirements at the melatonin receptor

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