scholarly journals Synthetic Melatoninergic Ligands: Achievements and Prospects

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
N. V. Kostiuk ◽  
M. B. Belyakova ◽  
D. V. Leshchenko ◽  
V. V. Zhigulina ◽  
M. V. Miniaev
Keyword(s):  
Circadian Rhythms ◽  
Melatonin Receptors ◽  
Animal Tissues ◽  
Synthetic Analogues ◽  
Recent Information ◽  
Structure Properties ◽  
Melatonin Analogues

Pineal hormone melatonin is widely used in the treatment of disorders of circadian rhythms. The presence of melatonin receptors in various animal tissues motivates the use of this hormone in some other diseases. For this reason, in recent years investigators continued the search for synthetic analogues of melatonin which are metabolically stable and selective to receptors. This review includes recent information about the most famous melatonin analogues, their structure, properties, and physiological features of the interaction with melatonin receptors.

234 EXPRESSION OF NUCLEAR AND MEMBRANE MELATONIN RECEPTORS GENES AND THE CLOCK GENES IN RAT OOCYTES: PRELIMINARY RESULTS

2010 ◽  
Vol 22 (1) ◽  
pp. 275
Author(s):  
L. A. Coelho ◽  
R. Peres ◽  
J. Cipolla-Neto
Keyword(s):  
Circadian Rhythms ◽  
Internal Control ◽  
Clock Genes ◽  
Receptor Gene ◽  
Cumulus Cells ◽  
Melatonin Receptors ◽  
Female Rats ◽  
Melatonin Receptor ◽  
Biomedical Sciences ◽  
Preliminary Results

There is evidence that melatonin acts directly on the regulation of ovary function. This action is probably attributed in part to melatonin receptors, which are known to be present in granulosa and cumulus cells (Kang J-T et al. 2009 J. Pineal Res. 46, 22–28). Melatonin is also known to be associated with the modulation of circadian rhythms and the regulation of seasonal reproductive function (Arendt J 1998 Rev. Reprod. 3, 13–22). Circadian rhythms and clock genes appear to be involved in reproductive processes (Dolatshad H et al. 2009 Repro. Fertil. Dev. 21, 1–9). However, the presence of melatonin receptor genes and the clock genes has not been so widely studied or has never been reported to exist in mammalian oocytes.The aim of this study was to investigate the presence of nuclear (Rorα) and membrane (Mt1 and Mt2) melatonin receptors genes and the clock genes (Clock, Bmal1, Cry1, Cry21, Per1, Per2) in rat oocytes by reverse RT-PCR. Twenty-seven-day-old Wistar female rats were treated with 20 UI of pregnant mares serum gonadotropin for induction of follicular development and slaughtered 48 h later. All the procedures involving animals were approved by the Animal Care Committee of the Institute of Biomedical Sciences. The ovaries were removed and placed in TCM-199 supplemented with 100 UI mL-1 penicillin, 100 μg mL-1 streptomycin, and 0.1% polyvinyl alcohol (H-199 medium). Germinal vesicle-intact oocytes, isolated from the ovarian follicles, were denuded from cumulus cells by vortexing for 5 to 8 min. The denuded oocytes were incubated for 5 min in H-199 medium with 0.1% pronase for removal of the zona pellucida. Pools of 80 oocytes per cDNA sample were used.As an internal control for the sample integrity, additional primers for RPL37a were included in each PCR reaction. All the 3 control PCR replicates showed a repeatable amplification. Polymerase chain reaction amplifications of cDNA yielded Rorα, Clock, Bmal1, and Cry1 products in 2 of 3 replicates. No expression of the MT1 and MT2 mRNA was observed. The preliminary results suggest the presence of a nuclear melatonin receptor gene and some clock genes in rat oocytes. However, additional studies are necessary to confirm this hypothesis. This research was supported by FAPESP.

Carbamate Insecticide Carbaryl Targets Melatonin Receptors and Modulates Circadian Rhythms

2018 ◽  
Vol 32 (S1) ◽  
Author(s):  
Grant C. Glatfelter ◽  
Rajendram V. Rajnarayanan ◽  
Margarita L. Dubocovich
Keyword(s):  
Circadian Rhythms ◽  
Melatonin Receptors ◽  
Carbamate Insecticide

Effects of two melatonin analogues, S-20098 and S-20928, on melatonin receptors in the pars tuberalis of the rat

1998 ◽  
Vol 25 (3) ◽  
pp. 172-176 ◽  
Author(s):  
M. Masson-Pévet ◽  
J. Recio ◽  
H. Y. Guerrero ◽  
E. Mocaer ◽  
Ph. Delagrange ◽  
...  
Keyword(s):  
Melatonin Receptors ◽  
Pars Tuberalis ◽  
Melatonin Analogues

scholarly journals Efficient Synthesis of [11C]Ramelteon as a Positron Emission Tomography Probe for Imaging Melatonin Receptors Involved in Circadian Rhythms

2011 ◽  
Vol 59 (8) ◽  
pp. 1062-1064 ◽  
Author(s):  
Misato Takashima-Hirano ◽  
Syusaku Tazawa ◽  
Kazuhiro Takahashi ◽  
Hisashi Doi ◽  
Masaaki Suzuki
Keyword(s):  
Positron Emission Tomography ◽  
Circadian Rhythms ◽  
Melatonin Receptors ◽  
Emission Tomography ◽  
Efficient Synthesis ◽  
Positron Emission

scholarly journals Neurobiology, Pathophysiology, and Treatment of Melatonin Deficiency and Dysfunction

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
Rüdiger Hardeland
Keyword(s):  
Circadian Rhythms ◽  
Sleep Disturbances ◽  
Bipolar Disorders ◽  
Diabetes Type 2 ◽  
Immediate Release ◽  
Melatonin Receptors ◽  
Prolonged Release ◽  
Common Symptom ◽  
Falling Asleep

Melatonin is a highly pleiotropic signaling molecule, which is released as a hormone of the pineal gland predominantly during night. Melatonin secretion decreases during aging. Reduced melatonin levels are also observed in various diseases, such as types of dementia, some mood disorders, severe pain, cancer, and diabetes type 2. Melatonin dysfunction is frequently related to deviations in amplitudes, phasing, and coupling of circadian rhythms. Gene polymorphisms of melatonin receptors and circadian oscillator proteins bear risks for several of the diseases mentioned. A common symptom of insufficient melatonin signaling is sleep disturbances. It is necessary to distinguish between symptoms that are curable by short melatonergic actions and others that require extended actions during night. Melatonin immediate release is already effective, at moderate doses, for reducing difficulties of falling asleep or improving symptoms associated with poorly coupled circadian rhythms, including seasonal affective and bipolar disorders. For purposes of a replacement therapy based on longer-lasting melatonergic actions, melatonin prolonged release and synthetic agonists have been developed. Therapies with melatonin or synthetic melatonergic drugs have to consider that these agents do not only act on the SCN, but also on numerous organs and cells in which melatonin receptors are also expressed.

FAILURE TO OBSERVE MITOTIC RHYTHMICITY IN ALLIUM MERISTEMS

1976 ◽  
Vol 18 (1) ◽  
pp. 189-194 ◽  
Author(s):  
Susan M. Erickson ◽  
William S. Hillman
Keyword(s):  
Cell Division ◽  
High Temperature ◽  
Circadian Rhythms ◽  
Low Temperature ◽  
Mitotic Index ◽  
Allium Cepa ◽  
Higher Plants ◽  
Animal Tissues ◽  
Shoot Meristems

Circadian rhythms clearly affect cell division in certain microorganisms and some animal tissues, but reports on mitotic rhythmicity in higher plants are contradictory, even for Allium cepa, the most widely studied material. Mitotic index was determined on root and shoot meristems of seedlings of one cultivar, and on roots of bulbs of another. Various times with respect to 24-h cycles of alternating light and darkness, or light-high temperature and darkness-low temperature were investigated. No evidence for rhythmicity was obtained.

scholarly journals The role of melatonin in the pathogenesis and therapy of depressive disorders (literature review)

2019 ◽  
Vol 25 (3) ◽  
pp. 147-154
Author(s):  
A. M. Skrypnikov ◽  
P. V. Kydon
Keyword(s):  
Circadian Rhythms ◽  
Depressive Disorders ◽  
Light Therapy ◽  
Melatonin Receptors ◽  
Antidepressant Effect ◽  
Biological Clocks ◽  
Laboratory Assessment ◽  
Literary Sources ◽  
Basic Facts

Background. Depression is one of the most common diseases worldwide. Despite the ongoing flow of research on affective disorders and the emergence of new antidepressants, depression remains a serious problem. Among the hypotheses of the occurrence of depressive disorders hypothesis associated with dysfunction of neurotransmitters and chronobiology concept (altered circadian rhythms that are implemented with the help of melatonin) occupy a leading place. The latter formed the basis of the melatonin theory of depression, the founder of which was A. Lewy. Objective – of this work was to review the literary sources that highlights the role of melatonin in the pathogenesis and therapy of depressive disorders. Materials and methods. Was analyzed publications from databases of Pubmed, Web of Science, Google Scholar with keywords – depression, melatonin, biorhythmology, agomelatine, desynchronosis. Results. According to the chronobiological concept of depression, the only cause of depressive disorders is the phase inconsistency of different circadian rhythms among themselves due to weakness in the work of their governing structures. In particular disorders of the central monoaminergic transmission is capable first and foremost negatively affect the role of lead retooling apparatus – suprachiasmatic nuclei of the hypothalamus, which leads to an acceleration of «progress» biological clocks and the formation of internal desynchronosis. Benefit chronobiological nature of the depressions suggest 3 basic facts: pronounced cyclicity in the clinical picture of the majority of depressive disorders and the availability of insomnia; the possibility of effective influence on the course of depression chronobiological methods (sleep deprivation, light therapy, therapy with «darkness»); the existence of many classes of antidepressants activity relative to circadian rhythms. A review of literature sources has shown that disorders of melatonin secretion is a characteristic feature of patients with depressive disorders. But the focus of this disturbance may be different: both downward and upward. This fact is due to the presence of biochemically different subgroups of depression. Antidepressant effect of melatonin today is quite controversial. The effect of another melatoninergic antidepressant, agomelatine, may be due to both the effect on melatonin receptors and antagonistic properties against serotonin 5-HT2C receptors. Conclusions. Each clinical case of depression is unique and requires careful evaluation to determine the quality of the therapeutic response to antidepressants. In this regard, there is a question of developing a differentiated approach to the treatment of various depressive disorders, in particular – a preliminary laboratory assessment of pineal function.

Trace nanoanalysis

1994 ◽  
Vol 52 ◽  
pp. 940-941
Author(s):  
D. E. Newbury ◽  
R. D. Leapman
Keyword(s):  
High Performance ◽  
Secondary Ion Mass Spectrometry ◽  
Detection Efficiency ◽  
Volume Element ◽  
And Performance ◽  
Trace Constituents ◽  
Secondary Ion ◽  
Concentration Levels ◽  
Structure Properties

Trace constituents, which can be very loosely defined as those present at concentration levels below 1 percent, often exert influence on structure, properties, and performance far greater than what might be estimated from their proportion alone. Defining the role of trace constituents in the microstructure, or indeed even determining their location, makes great demands on the available array of microanalytical tools. These demands become increasingly more challenging as the dimensions of the volume element to be probed become smaller. For example, a cubic volume element of silicon with an edge dimension of 1 micrometer contains approximately 5×1010 atoms. High performance secondary ion mass spectrometry (SIMS) can be used to measure trace constituents to levels of hundreds of parts per billion from such a volume element (e. g., detection of at least 100 atoms to give 10% reproducibility with an overall detection efficiency of 1%, considering ionization, transmission, and counting).

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