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Physiological Research Dec 2019The pineal gland (glandula pinealis) is neuroendocrine gland located at the epithalamus of the brain secreting melatonin. The aim of this study was to explore effects of...
The pineal gland (glandula pinealis) is neuroendocrine gland located at the epithalamus of the brain secreting melatonin. The aim of this study was to explore effects of prenatal hypoxia in rats at the age of 33 weeks on the occurrence of pineal gland calcification. Distribution and chemical composition of calcerous material by light, scanning and transmission electron microscopy was investigated. Melatonin concentrations in blood plasma by direct radioimmunoassay were measured. Rats were exposed to prenatal hypoxia for 12 h at day 20 of development and second group to prenatal hypoxia for 2x8 h at days 19 and 20 of development. Vacuoles of intracellular edema in the pineal samples after 12 h hypoxia were found. Their size ranges up to 30 µm. Some of them were filled with the flocculent and fibrous material. Samples of pineal glands after 2 x 8 h hypoxia revealed the pericellular edema of pinealocytes. The amount of calcium rich particles in 2 x 8 h hypoxia group was lower than in 12 h hypoxia group. Plasma melatonin levels did not differ between control and both hypoxia groups. We concluded that calcification is a process induced by osteoblasts and osteocytes with melatonin as a promotor and it is favored under hypoxic conditions.
Topics: Animals; Calcinosis; Hypoxia; Male; Pineal Gland; Rats, Wistar
PubMed: 32118471
DOI: 10.33549/physiolres.934378 -
Molecular and Cellular Endocrinology Feb 2012The pineal gland is a neuroendocrine organ of the brain. Its main task is to synthesize and secrete melatonin, a nocturnal hormone with diverse physiological functions.... (Review)
Review
The pineal gland is a neuroendocrine organ of the brain. Its main task is to synthesize and secrete melatonin, a nocturnal hormone with diverse physiological functions. This review will focus on the central and pineal mechanisms in generation of mammalian pineal rhythmicity including melatonin production. In particular, this review covers the following topics: (1) local control of serotonin and melatonin rhythms; (2) neurotransmitters involved in central control of melatonin; (3) plasticity of the neural circuit controlling melatonin production; (4) role of clock genes in melatonin formation; (5) phase control of pineal rhythmicity; (6) impact of light at night on pineal rhythms; and (7) physiological function of the pineal rhythmicity.
Topics: Animals; CLOCK Proteins; Circadian Clocks; Cryptochromes; Gene Expression Regulation; Humans; Melatonin; Photoperiod; Pineal Gland; Serotonin
PubMed: 21782887
DOI: 10.1016/j.mce.2011.07.009 -
British Journal of Pharmacology Aug 2018Melatonin is well known for its circadian production by the pineal gland, and there is a growing body of data showing that it is also produced by many other cells and... (Review)
Review
Melatonin is well known for its circadian production by the pineal gland, and there is a growing body of data showing that it is also produced by many other cells and organs, including immune cells. The chronobiotic role of pineal melatonin, as well as its protective effects in vitro and in vivo, have been extensively explored. However, the interaction between the chronobiotic and defence functions of endogenous melatonin has been little investigated. This review details the current knowledge regarding the coordinated shift in melatonin synthesis from the pineal gland (circadian and monitoring roles) to the regulation of acute immune responses via immune cell production and autocrine effects, producing systemic interactions termed the immune-pineal axis. An acute inflammatory response drives the transcription factor, NFκB, to switch melatonin synthesis from pinealocytes to macrophages/microglia and, upon acute inflammatory resolution, back to pinealocytes. The potential pathophysiological relevance of immune-pineal axis dysregulation is highlighted, with both research and clinical implications, across several medical conditions, including host/parasite interaction, neurodegenerative diseases and cancer. LINKED ARTICLES: This article is part of a themed section on Recent Developments in Research of Melatonin and its Potential Therapeutic Applications. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.16/issuetoc.
Topics: Animals; Humans; Immunity, Innate; Inflammation; Melatonin; Neoplasms; Phagocytes; Pineal Gland
PubMed: 29105727
DOI: 10.1111/bph.14083 -
Psychiatria Danubina Jun 2015The majority of patients with schizophrenia and mood disorders have disruptions in sleep and circadian rhythm. Melatonin, which is secreted by the human pineal gland,... (Comparative Study)
Comparative Study
BACKGROUND
The majority of patients with schizophrenia and mood disorders have disruptions in sleep and circadian rhythm. Melatonin, which is secreted by the human pineal gland, plays an important role in sleep and circadian rhythm. The aim of the present study was to evaluate and compare pineal gland volumes in patients with schizophrenia and mood disorders.
SUBJECTS AND METHODS
We retrospectively evaluated the pineal gland volumes of 80 cases, including 16 cases of unipolar depression, 17 cases of bipolar disorder, 17 cases of schizophrenia, and 30 controls. The total pineal gland volume of all cases was measured via magnetic resonance images, and the total mean pineal volume of each group was compared.
RESULTS
The mean pineal volumes of patients with schizophrenia, bipolar disorder, unipolar depression, and the controls were 83.55±10.11 mm(3), 93.62±11.00 mm(3), 95.19±11.61 mm(3) and 99.73±12.03 mm(3), respectively. The mean pineal gland volume of the patients with schizophrenia was significantly smaller than those of the other groups.
CONCLUSIONS
Our data show that patients with schizophrenia have smaller pineal gland volumes, and this deviation in pineal gland morphology is not seen in those with mood disorders. We hypothesize that volumetric changes in the pineal gland of patients with schizophrenia may be involved in the pathophysiology of this illness.
Topics: Adult; Bipolar Disorder; Depressive Disorder, Major; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Pineal Gland; Schizophrenia
PubMed: 26057310
DOI: No ID Found -
Neurochemical Research Jun 2013The pineal gland is a neuroendocrine gland responsible for nocturnal synthesis of melatonin. During early development of the rodent pineal gland from the roof of the... (Review)
Review
The pineal gland is a neuroendocrine gland responsible for nocturnal synthesis of melatonin. During early development of the rodent pineal gland from the roof of the diencephalon, homeobox genes of the orthodenticle homeobox (Otx)- and paired box (Pax)-families are expressed and are essential for normal pineal development consistent with the well-established role that homeobox genes play in developmental processes. However, the pineal gland appears to be unusual because strong homeobox gene expression persists in the pineal gland of the adult brain. Accordingly, in addition to developmental functions, homeobox genes appear to be key regulators in postnatal phenotype maintenance in this tissue. In this paper, we review ontogenetic and phylogenetic aspects of pineal development and recent progress in understanding the involvement of homebox genes in rodent pineal development and adult function. A working model is proposed for understanding the sequential action of homeobox genes in controlling development and mature circadian function of the mammalian pinealocyte based on knowledge from detailed developmental and daily gene expression analyses in rats, the pineal phenotypes of homebox gene-deficient mice and studies on development of the retinal photoreceptor; the pinealocyte and retinal photoreceptor share features not seen in other tissues and are likely to have evolved from the same ancestral photodetector cell.
Topics: Animals; Circadian Rhythm; Gene Expression Regulation, Developmental; Genes, Homeobox; Homeodomain Proteins; Melatonin; Mice; Otx Transcription Factors; Phenotype; Photoreceptor Cells, Invertebrate; Photoreceptor Cells, Vertebrate; Phylogeny; Pineal Gland; Rats; Trans-Activators
PubMed: 23076630
DOI: 10.1007/s11064-012-0906-y -
Aging Jan 2020We aimed to investigate the association of pineal gland volume with the risk of isolated rapid eye movement (REM) sleep behavior disorder (RBD). We enrolled 245...
We aimed to investigate the association of pineal gland volume with the risk of isolated rapid eye movement (REM) sleep behavior disorder (RBD). We enrolled 245 community-dwelling cognitively normal elderly individuals without major psychiatric or neurological disorders at the baseline evaluation, of whom 146 completed the 2-year follow-up evaluation. We assessed RBD symptoms using the REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ) and defined probable RBD (pRBD) as an RBDSQ score of ≥ 5. We manually segmented the pineal gland on 3T T1-weighted brain magnetic resonance imaging and estimated its volume. The smaller the baseline pineal gland volume, the more severe the RBD symptoms at baseline. The individuals with isolated pRBD showed smaller pineal gland volumes than those without isolated pRBD. The larger the baseline pineal gland volume, the lower the risks of prevalent isolated pRBD at the baseline evaluation and incident isolated pRBD at the 2-year follow-up evaluation. Pineal gland volume showed good diagnostic accuracy for prevalent isolated pRBD and predictive accuracy for incident isolated pRBD in the receiver operator characteristic analysis. Our findings suggest that pineal gland volume may be associated with the severity of RBD symptoms and the risk of isolated RBD in cognitively normal elderly individuals.
Topics: Age Factors; Aged; Aged, 80 and over; Aging; Disease Susceptibility; Female; Humans; Incidence; Male; Organ Size; Pineal Gland; Prevalence; REM Sleep Behavior Disorder; ROC Curve; Risk Assessment; Risk Factors
PubMed: 31918412
DOI: 10.18632/aging.102661 -
The European Journal of Neuroscience Jun 2017Several cell types in the pineal gland are known to establish intercellular gap junctions, but the connexin constituents of those junctions have not been fully...
Several cell types in the pineal gland are known to establish intercellular gap junctions, but the connexin constituents of those junctions have not been fully characterized. Specifically, the expression of connexin36 (Cx36) protein and mRNA has been examined in the pineal, but the identity of cells that produce Cx36 and that form Cx36-containing gap junctions has not been determined. We used immunofluorescence and freeze fracture replica immunogold labelling (FRIL) of Cx36 to investigate the cellular and subcellular localization of Cx36 in the pineal gland of adult mouse and rat. Immunofluorescence labelling of Cx36 was visualized exclusively as puncta or short immunopositive strands that were distributed throughout the pineal, and which were absent in pineal sections from Cx36 null mice. By double immunofluorescence labelling, Cx36 was localized to tryptophan hydroxylase-positive and 5-hydroxytryptamine-positive pinealocyte cell bodies and their large initial processes, including at intersections of those processes and at sites displaying a confluence of processes. Labelling for the cell junction marker zonula occludens-1 (ZO-1) either overlapped or was closely associated with labelling for Cx36. Pinealocytes thus form Cx36-containing gap junctions that also incorporate the scaffolding protein ZO-1. FRIL revealed labelling of Cx36 at ultrastructurally defined gap junctions between pinealocytes, most of which was at gap junctions having reticular, ribbon or string configurations. The results suggest that the endocrine functions of pinealocytes and their secretion of melatonin is supported by their intercellular communication via Cx36-containing gap junctions, which may now be tested by the use of Cx36 null mice.
Topics: Animals; Connexins; Gap Junctions; Male; Mice; Mice, Inbred C57BL; Pineal Gland; Rats; Rats, Sprague-Dawley; Gap Junction delta-2 Protein
PubMed: 28474748
DOI: 10.1111/ejn.13602 -
Italian Journal of Pediatrics Mar 2022The causes of an early onset of puberty are still not clearly defined and may vary from subject to subject. In girls, even if 90% of early puberty is idiopathic,...
BACKGROUND
The causes of an early onset of puberty are still not clearly defined and may vary from subject to subject. In girls, even if 90% of early puberty is idiopathic, magnetic resonance imaging (MRI) of the brain is performed to exclude secondary causes of precocious puberty, in particular pathological lesions as hypothalamic tumours (hamartoma). In some cases, other intracranial lesions are considered as incidental findings. Aim of the study is evaluating the prevalence of abnormal intracranial lesions detected by brain magnetic resonance imaging MRI with particular focus on the prevalence of pineal gland cysts in the diagnostic work-up of girls with central precocious puberty (CPP) as onset before 8 years and central early puberty (CEP) as onset before 10 years.
MATERIAL AND METHODS
MRI data of girls referred from January 2010 to December 2015 to the Pediatric Endocrinology Unit of University of Pavia for early onset of breast development were collected.
RESULTS
We collected 123 MRI data of girls referred to the Pediatric Endocrinology Unit of University of Pavia for early onset of breast development in the study period. Out of them, 25 (20.3%) had cerebral abnormalities and 15 (12.2%) had pineal gland cysts. No significant differences were noted in auxological, ultrasound and hormonal parameters at diagnosis among girls with or without pineal cysts. Patients have been observed for at least three years after the discontinuation of therapy. None of our patients had an unfavorable evolution.
CONCLUSIONS
Although pineal cysts seem to be not involved in the onset of puberty, the relevance of the finding remains controversial. Our study wants to provide further insight into the incidence of pineal cysts in pubertal advances. Of note, pineal cysts are often asymptomatic and do not evolve over time.
Topics: Child; Cysts; Endocrine System Diseases; Female; Humans; Pineal Gland; Puberty; Puberty, Precocious
PubMed: 35313951
DOI: 10.1186/s13052-022-01235-4 -
Journal of Pineal Research Apr 2021The human pineal gland regulates day-night dynamics of multiple physiological processes, especially through the secretion of melatonin. Using mass-spectrometry-based...
The human pineal gland regulates day-night dynamics of multiple physiological processes, especially through the secretion of melatonin. Using mass-spectrometry-based proteomics and dedicated analysis tools, we identify proteins in the human pineal gland and analyze systematically their variation throughout the day and compare these changes in the pineal proteome between control specimens and donors diagnosed with autism. Results reveal diverse regulated clusters of proteins with, among others, catabolic carbohydrate process and cytoplasmic membrane-bounded vesicle-related proteins differing between day and night and/or control versus autism pineal glands. These data show novel and unexpected processes happening in the human pineal gland during the day/night rhythm as well as specific differences between autism donor pineal glands and those from controls.
Topics: Autistic Disorder; Case-Control Studies; Circadian Rhythm; Humans; Pineal Gland; Protein Interaction Maps; Proteins; Proteome; Proteomics; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Time Factors
PubMed: 33368564
DOI: 10.1111/jpi.12713 -
Identifying daily changes in circRNAs and circRNA-associated-ceRNA networks in the rat pineal gland.International Journal of Medical... 2021Circular RNAs (circRNAs) are a new class of covalently closed circular RNA molecules that are involved in many biological processes. However, information about circRNAs...
Circular RNAs (circRNAs) are a new class of covalently closed circular RNA molecules that are involved in many biological processes. However, information about circRNAs in the pineal gland, particularly that of rats, is limited. To establish resources for the study of the rat pineal gland, we performed transcriptome analysis of the pineal glands during the day and night. In this study, 1413 circRNAs and 1989 miRNAs were identified in the pineal gland of rats during the night and day using the Illumina platform. Forty differentially expressed circRNAs and 93 differentially expressed miRNAs were obtained, among which 20 circRNAs and 37 miRNAs were significantly upregulated during the day and 20 circRNAs and 56 miRNAs were significantly upregulated during the night. As circRNAs have been reported to work as miRNA sponges, we predicted 15940 interactions among 40 circRNAs, 93 miRNAs and 400 mRNAs with differential diurnal expression using miRanda and TargetScan to build a ceRNA regulatory network in the rat pineal gland. The diurnal expression profile of circRNAs in the rat pineal gland may provide additional information about the role of circRNAs in regulating changes in melatonin circadian rhythms. The analyzed data reported in this study will be an important resource for future studies to elucidate the altered physiology of circRNAs in diurnal rhythms.
Topics: Animals; Circadian Rhythm; Gene Expression Profiling; Gene Expression Regulation; Gene Regulatory Networks; Male; Melatonin; MicroRNAs; Models, Animal; Photoperiod; Pineal Gland; RNA, Circular; RNA, Messenger; Rats
PubMed: 33526984
DOI: 10.7150/ijms.51743