Here, we report a novel function of the transporter in rat pinealocytes. In pineal slices with densely packed pinealocytes, glutamate released from the cells effectively activated glutamate transporters in neighboring cells. The Ca2+ signal generated by KCl depolarization or acetylcholine propagated through several cell layers by virtue of the regenerative "glutamate-induced glutamate release." Therefore, we suggest that glutamate transporters mediate synchronized elevation of L-glutamate and thereby efficiently downregulate melatonin secretion via previously identified inhibitory metabotropic glutamate receptors in the pineal gland.. 
The pineal gland hormone melatonin has been recently described to downregulate the intrinsic (or damage-induced) pathway of apoptosis in human leukocytes.
Transient serotonin-immunoreactive cells were noted in the pineal organ, habenula, and pretectum.
Here, we examine the effect of ischemic stroke on circadian rhythms in rats using high resolution pineal microdialysis. METHODS: Rats were housed in LD 12:12h conditions and monitored by pineal microdialysis to determine baseline melatonin timing profiles. CONCLUSIONS: This is the first demonstration that stroke induces immediate changes in the timing of pineal melatonin secretion, indicating that cortical and basal ganglia infarction impacts the circadian pacemaker. Finally, our study exemplifies the use of pineal microdialysis to evaluate the effect of forebrain diseases on circadian function..
Oxidative stress and melatonin (the pineal hormone) are involved in the pathogenesis of aging and aging-related diseases, including essential arterial hypertension.
RATIONALE: Animal studies suggest that the pineal hormone melatonin influences basal stress hormone levels and dampens hormone reactivity to stress.
Endodermal sinus tumor, or yolk sac tumor, is the most common malignant neoplasm of germ cell origin and usually occurs in infant testes or ovaries.(1) On rare occasions, the tumor may arise from extragonadal sites, including sacrococcygeal region, uterus, vagina, prostate, retroperitoneum, liver, mediastinum, pineal gland, and third ventricle.(1) The orbit is an unusual location for the primary development of this neoplasm.(2,3) We report the case of a girl with primary orbital endodermal sinus tumor who was managed with exenteration and chemotherapy with the result of a disease-free survival of 9 years..
Furthermore, the pineal hormone melatonin is involved in the regulation of reproductive function, including the timing of the luteinizing hormone surge.
pinealgland tumors comprise 0.5%-1% of adult brain tumors. Pineoblastomas constitute less than half of these pineal gland tumors.
ADAM22 expression is strong in some brain nuclei and in the pineal gland.
Metastases to the pineal gland are rare and reported cases have consisted primarily of gastrointestinal and lung primary malignancies. Here we present the case of a 66-year-old female with autosomal dominant polycystic kidney and liver disease who was found at autopsy to have an unrecognized infiltrating ductal adenocarcinoma of the pancreas with metastases to the liver, lungs and pineal gland. As far as we are aware, this is the first report of a metastasis of infiltrating ductal adenocarcinoma of the pancreas to the pineal gland..
The Gestational Zinc Deficiency Theory suggests that the schizophrenia is caused by a spectrum of damage, produced in utero, to zinc dependent fetal organs such as the brain, pancreas, pineal, testes etc. A far better explanation is provided by assuming that geomagnetic field induced loss of pineal activity in the mother during pregnancy permanently affects pineal entrainment in the fetus.
The pineal hormone melatonin is able to shift the timing of circadian rhythms, including the sleep-wake cycle, and to promote sleep.
Glial cysts of the pineal gland are benign and mostly asymptomatic incidental lesions found in the brain MRI or at autopsy examinations. In rare cases pineal cysts become symptomatic and require surgical intervention. Symptomatic glial cysts may be clinically and radiologically indistinguishable from cystic neoplasms of the pineal region; therefore, histopathological diagnosis is critical for further prognosis and therapy in operated patients. In this paper we present detailed histopathological characteristics of symptomatic glial cysts in 2 surgical cases and of asymptomatic cysts of the pineal gland found at random in 3 autopsy cases. Preoperative MR imaging suggested tumour of the pineal gland in case no. Histopathological and immunohistochemical examination of the specimens from both surgical and all autopsy cases revealed a characteristic pattern of cystic structures within the pineal gland, surrounded by layers of a dense fibrillar glial tissue and pineal parenchyma, consistent with non-neoplastic glial cysts. Although histopathological findings in asymptomatic and symptomatic cysts are essentially the same, the cyst in surgical case 1 was unilocular and partly lined with ependymal cells, whereas the cysts in other cases were multilocular, comprising cavities of various size, formed in the central part of gliotic tissue or directly within the pineal parenchyma, and lacked ependymal lining. Possible pathophysiological and clinicopathological significance of some morphological variants of pineal glial cysts is discussed..
After the discovery of melatonin in the pineal gland by Lerner and co-workers in 1958, melatonin was also detected in the retina and the human appendix. The concentrations of melatonin in the GIT are 10-100x higher than in the plasma and the total amount of melatonin in the GIT is around 400x higher than the amount of melatonin in the pineal gland. Similar to pineal melatonin, GIT melatonin is a multifunctional compound which exhibits some general as well as some specific effects, depending on the organ and the location of GIT tissue.
Six new entities were codified: angiocentric glioma (AG); papillary glioneuronal tumour (PGNT); rosette-forming glioneuronal tumour of the fourth ventricle (RGNT); papillary tumour of the pineal region (PTPR); spindle cell oncocytoma of the adenohypophysis (SCO); and pituicytoma.
The newly codified entities are: angiocentric glioma, pilomyxoid astrocytoma, papillary glioneuronal tumor, rosette-forming glioneuronal tumor of the 4th ventricle, papillary tumour of the pineal region, spindle cell oncocytoma and pituicytoma.
Pax6 is essential for development of the pineal gland. In this study, we report that Pax4 is strongly expressed in the pineal gland and retina of the rat. pineal Pax4 transcripts are low in the fetus and increase postnatally; Pax6 exhibits an inverse pattern of expression, being more strongly expressed in the fetus. In the adult, the abundance of Pax4 mRNA exhibits a diurnal rhythm in the pineal gland with maximal levels occurring late during the light period. Sympathetic denervation of the pineal gland by superior cervical ganglionectomy prevents the nocturnal decrease in pineal Pax4 mRNA. At night, the pineal gland is adrenergically stimulated by release of norepinephrine from the sympathetic innervation; here, we found that treatment with adrenergic agonists suppresses pineal Pax4 expression in vivo and in vitro. This suppression appears to be mediated by cyclic AMP, a second messenger of norepinephrine in the pineal gland, based on the observation that treatment with a cyclic AMP mimic reduces pineal Pax4 mRNA levels. These findings suggest that the nocturnal decrease in pineal Pax4 mRNA is controlled by the sympathetic neural pathway that controls pineal function acting via an adrenergic-cyclic AMP mechanism. The daily changes in Pax4 expression may influence gene expression in the pineal gland..
Melatonin production in cannulated or ophthalmectomized fish and its secretion from cultured pineal glands were examined under several light regimes. Static pineal gland culture under light-dark and reverse light-dark cycles revealed that melatonin synthesis increased during the dark periods. Rhythmic melatonin synthesis disappeared on pineal gland culture under constant dark and light conditions. These results suggest that (1) Mozambique tilapias possess strong photic responsiveness, (2) their pineal glands are sensitive to light but lack circadian pacemaker activity, and (3) they require lateral eyes for rhythmic melatonin secretion from the pineal gland..
By 3-5 days postfertilization, ar transcripts were also detected in the pineal organ anlage and the retina.
Tumors of the pineal region are rare and relatively few centers around the world have published substantial numbers of carefully studied cases. This review gives a historical account of our understanding of the normal pineal and the evolution of the classification of tumors and other mass lesions of the pineal region in human beings.
BACKGROUND AND OBJECTIVE: The pineal parenchymal tumors are rare, comprising 15-30% of all tumors of pineal region. METHODS: A retrospective analysis of 33 pineal parenchymal tumors treated from 1990-2004 was performed. RESULTS: The study comprised 6 pineocytomas (PC), 17 pineoblastomas (PB) and 10 pineal parenchymal tumors with intermediate differentiation (PPT-ID) which included 3 mixed PC/PB. CONCLUSIONS: Neurofilament immunoreactivity indicates better prognosis in pineal parenchymal tumors. The MIB-1 labeling index can be utilized as an additional tool to differentiate pineal parenchymal tumors into various subgroups..
MT content of pineal gland tissue was determined by high performance liquid chromatography (HPLC) and neuroethological scores of the rats were evaluated by Kuluz's and Julio's methods. Compared with model group, pineal MT content, neuroethological score and Bcl-2 IR-positive cells in EA group, neuroethological scores in EA+L and EA+P groups, and Bcl-2 expression in MT and EA+MT groups increased considerably (P<0.01, 0.001); while Bax IR-positive cells and Bax/Bcl-2 in EA, MT and EA+MT groups decreased very significantly (P<0.001). It showed that EA could obviously increase pineal MT content, improve CI-RI rats' activity score, upregulate Bcl-2 expression and down-regulate Bax expression in striate body.
The pineal gland or epiphysis of brain is endocrine, producing the melatonin. pineals were measured and a medium size was found to be 2.3-mm-long and 1.3-mm-wide. pineal gland was located in the habenular commissure in the most caudal portion of the third ventricular roof, lying in a dorso-caudal position from the base to the apex. pinealocytes were predominantly found in the glandular parenchyma. Distinct and heterogeneous arrangements of these cells throughout the three pineal portions were observed as follows: linear cords at the apex, circular cords at the base of the gland, whereas at the body a transition arrangement was found. The pineal gland was classified as subcallosal type [ Rec. 42, 25 (1979); The pineal Organ, Berlin/Heidelberg: Springer-Verlag (1981)]..
As cells in the SCN are lost with age, their circadian and homeostatic functioning fails, the activity of the hypothalamus-pineal axis is reduced and the endogenous melatonin rhythm is altered.
Germinomas in the central nervous system (CNS) are uncommon tumors and occur usually in the pineal or suprasellar regions.
Seven patients had pineal PNET.
Opsin genes are expressed in a cell-type specific manner in the retina and the pineal organ for visual and non-visual photoreceptive purposes, but the regulatory mechanism behind the tissue and cell selectivity is not well understood. We found that (1) a 0.3-kb region between 0.6 and 0.3 kb 5' of the SWS2 initiation codon, encompassing four cone-rod homeobox (Crx) binding sites (OTX sequences), contains the region necessary and sufficient to drive gene expression in LSCs, (2) a 15-bp portion (-341~-327) in the 0.3-kb region represses the gene expression in the "short single cones" (SSCs) which are dedicated to the UV-sensitive opsin gene SWS1, (3) an 11-bp sequence TAACTGCCAGT (-441~-431) in the 0.3-kb region, with its adjacent OTX element, also works as a repressor for gene expression in the pineal cells, and (4) this OTX site is necessary for expression repression in the bipolar cells in the retina. These findings open a way for understanding the complex interaction of positive and negative regulatory factors that governs the cell-type specificity of the opsin gene expression in the photoreceptive cells in the retina and the pineal organ. We termed the novel 11-bp sequence as the pineal negative regulatory element, PINE..
Some polymorphisms in TPH1 and AANAT, the genes of 2 critical enzymes involved in melatonin biosynthesis, may contribute to variability of melatonin production in pineal glands.
On the basis of the analysis of the clinically pathologic correlations and direct and longstanding operative results of the surgical treatment of cavernoma, operative treatment is indicated in all superficial lobar lesions as well as in those that are localized in the brain chambers and pineal region regardless of the type of the clinical presentation..
The effect of melatonin, a major secretory product of the pineal gland, in attenuation of propoxur (2-isopropoxy phenyl N-methyl carbamate)-induced modulation of cell-mediated immune (CMI) response was studied in rats.
In mammals, extraretinal photoreceptors have been lost, and the nocturnal melatonin signal generated from the pineal gland has been co-opted to provide the photoperiodic message. pineal function is phased to the light-dark cycle by retinal input, and photoperiodic changes in melatonin secretion control neuroendocrine pathway function.
This puts new light on some existing research findings: that estrogen depletion can increase pineal melatonin, that the ability of light to suppress pineal melatonin is more variable than once thought, and that an altered melatonin cycle is associated with rheumatoid arthritis patients, where identical circadian symptoms present. Not all frequencies of retinal light are equally effective at suppressing pineal melatonin; most artificial lighting has less relevant spectral density than sunlight.
Arylalkylamine N-acetyltransferase (AA-NAT) is the rhythm-generating enzyme for the synthesis of pineal melatonin. In agreement with this hypothesis, we report herein the amount of Aa-nat mRNA in the camel pineal gland is high, during both the day and night with no daily variations, while melatonin concentration in the same pineal tissue is five times higher during the night than daytime..
pineal parenchyma tumor of intermediate differentiation (PPTID) is a very rare intracranial tumor, and pathological investigation limited to immunohistological and ultrastructural analyses have been published to date. Brain MRI revealed an unhomogeneously enhanced, large-sized tumor (56 x 52 x 60 mm) mainly located in the pineal region expanding from the midbrain to superior portion of the cerebellum and the fourth ventricle. This is the first presentation of cytological analysis by squash preparation that gives an important clue to accurate diagnosis of pineal parenchymal tumor and to understand its malignant potential..
Serotonin N-acetyltransferase [ arylalkylamine N-acetyltransferase (AANAT)] is a key circadian rhythm enzyme that drives the nocturnal production of melatonin in the pineal.
Moreover, the responses to head illumination (eyes and pineal) did not correspond with the observed light avoidance behaviors.
Trilateral retinoblastoma is characterized by retinal tumors in one or both eyes, as well as tumors of the pineal gland or parasellar region of the brain. We recommend that if a pineal or suprasellar tumor is observed in a child, the eyes should be examined for retinoblastoma, thereby avoiding biopsies of the intracranial tumor, which may track difficult-to-treat tumor cells through the brain, and disseminate tumor cells into the CSF..
Its production in the pineal gland has been extensively investigated but other organs also synthesize this important amine.
The thalamus has a strong nonphotic influence on sleep, circadian rhythmicity, pineal melatonin production, and secretion. A remarkable similarity exists between spindle behavior, circadian rhythmicity, and pineal melatonin production throughout life.
We report an unusual case of sarcoidosis involving the pineal gland with radiographic, histopathology, and clinical data. MR imaging demonstrated an enhancing mass in the pineal region. Histopathologic analysis did not reveal a pineoblastoma but instead revealed noncaseating granulomas within the pineal gland. This mass lesion was diagnosed as solitary neurosarcoidosis of the pineal gland, without dissemination. Conclusion This is an unusual case of pineal sarcoidosis mimicking a tumor with associated MRI, CT and histopathologic findings reported together. Although rare, sarcoidosis of the pineal gland should not be excluded from a comprehensive differential diagnosis of an enhancing pineal region mass..
An immunohistochemical study of the density of melatonin receptors 1A in the neurons of the rat suprachiasmatic nuclei with diverse functional activity of the pineal gland has been carried out. The density of melatonin receptors 1A under conditions of the physiological function of the pineal gland was characterized by clear-cut diurnal variations. In case of a hypofunction of the pineal body the density of the structures was reliably lower than in case of hyperfunction. It has been demonstrated that in case of a suppressed activity of the pineal body the maximum number of melatonin receptors 1A in the neurons of the hypothalamic suprachiasmatic nuclei shifts from 02.00 a.m.
The aim of our study was, therefore, to determine the relationship between the degree of pineal calcification (DOC) and a range of sleep parameters measured objectively using polysomnography (PSG). DOC and volume of calcified pineal tissue (CPT) and uncalcified pineal tissue (UPT) were estimated by means of cranial computed tomography.
Infarcts were found in seven, intracranial hemorrhage in seven, hydrocephaly in two, dural sinus thrombosis in two and a pineal cyst in one patient.
ABSTRACT: INTRODUCTION: Glioblastoma in the pineal region is extremely rare with only a few cases reported in the literature. A magnetic resonance imaging study revealed a heterogeneously ring-enhanced mass in the pineal region. CONCLUSION: We discuss the clinical course, radiological findings and treatment strategies of pineal glioblastoma with a review of the relevant literature..
In mammals this depends on pineal melatonin secretion and effects in the hypothalamus, but the cellular and molecular substrates of its action are poorly understood.
Dynamics of rhythmic oscillations in the activity of arylalkylamine N-acetyltransferase (AA-NAT, the penultimate and key regulatory enzyme in melatonin biosynthesis) were examined in the retina and pineal gland of turkeys maintained for 7 days in the environment without daily light-dark (LD) changes, namely constant darkness (DD) or continuous light (LL). In the retina, a circadian AA-NAT activity rhythm disappeared after 5 days of DD, while in the pineal gland it persisted for the whole experiment. No circadian rhythm was observed in the retinas of turkeys exposed to LL, although rhythmic oscillations in both AA-NAT and melatonin content were found in the pineal glands. It is suggested that the retina of turkey is less able to maintain rhythmicity in constant environment and is more sensitive to changes in the environmental lighting conditions than the pineal gland. Our results indicate that, in contrast to mammals, pineal glands of light-exposed galliformes maintain the limited capacity to rhythmically produce melatonin..
Melatonin (MEL) is synthesized mainly in the pineal gland and derived from 5-hydroxytryptophan (5-HTP).
The majority of third ventricular meningiomas are located posteriorly in the pineal region.
Additionally, (n-3) PUFA affect pineal function, which is implicated in the sleep-wake rhythm. We investigated the effect of an (n-3) PUFA-deficient diet on locomotor and pineal melatonin rhythms in Syrian hamsters used as model species in circadian rhythm research. In (n-3) PUFA-deficient hamsters, the induced changes in the pineal PUFA membrane phospholipid composition were associated with a reduction in the nocturnal peak level of melatonin that was 52% lower than in control hamsters (P < 0.001).
The morphological relationships of the pineal complex to the epithalamic structures have been examined at light microscopic level in five desert rodent species, Meriones crassus, Meriones lybicus, Gerbillus gerbillus, Psammomys obesus and Ctenodactylus vali. The pineal complex is classified as type ABC in M. In these rodent species, the pineal is an elongated organ which is dumbbell-shaped in G. In all species examined, the suprahabenular recess which is an extension of the choroid plexus of the third ventricule establishes a close anatomical relationship with the deep pineal. vali, the suprahabenular recess is also contiguous with the pineal stalk and the superficial pineal component. The most striking feature noted in this study is the presence of numerous melanocytes in the connective tissue capsule of the pineal gland, in the connecting stalk and in the connective tissue core of the highly convoluted suprahabenular recess in M. The location of melanocytes in the restricted pineal area may suggest that these cells have a morphosignificance in photoreception or photoprotection..
OBJECTIVE: Direct surgical approaches to the posterior incisural space, including the pineal region, remain as challenges for neurosurgeons.
Besides to their brainstem location where I1-receptor sites play a significant role to regulate and modulate blood pressure, they also are found in different parts of brain with the highest densities in the striatum, pallidum, hippocampus, amygdala, substantia nigra, while I3-receptor sites were revealed in pancreas which enhances insulin secretion, I2-receptors are widely distributed in interpeduncular nucleus, arcuate and pineal gland and take a part in monoamine turnover.
Bright light is used in the treatment of SAD, melatonin, the pineal hormone, is also of interest when administered at precise timings in the 24hours scale.
Serotonin (5-hydroxytryptamine, 5-HT), a precursor for melatonin production, is produced abundantly in the pineal gland of all vertebrate animals. The synthesis of 5-HT in the pineal gland is rate limited by tryptophan hydroxylase 1 (TPH1) whose activity displays a twofold increase at night. Earlier studies from our laboratory demonstrate that pineal 5-HT secretion exhibits dynamic circadian rhythms with elevated levels during the early night, and that the increase is controlled by adrenergic signaling at night. In this study, we report that (a) 5-HT total output from the pineal gland and TPH1 protein levels both display diurnal rhythms with a twofold increase at night; (b) stimulation of cAMP signaling elevates 5-HT output in vivo; (c) 5-HT total output and TPH1 protein content in rat pineal gland are both acutely inhibited by light exposure at night. Consistent with these findings, molecular analysis of TPH1 protein revealed that (a) TPH1 is phosphorylated at the serine 58 in vitro and in the night pineal gland; and (b) phosphorylation of TPH1 at this residue is required for cAMP-enhanced TPH1 protein stability. These data support the model that increased nocturnal 5-HT synthesis in the pineal gland is mediated by the phosphorylation of TPH1 at the serine 58, which elevates the TPH1 protein content and activity at night..
We measured the absolute displacement of a midline structure, the pineal gland, on brain scans of 39 migraineurs and 26 controls. We found a significant asymmetry of the pineal gland in migraineurs compared with controls.
Aspartate is an excitatory amino acid that is costored with glutamate in synaptic vesicles of hippocampal neurons and synaptic-like microvesicles (SLMVs) of pinealocytes and is exocytosed and stimulates neighboring cells by binding to specific cell receptors. Here, we show that sialin, a lysosomal H(+)/sialic acid cotransporter, is present in hippocampal synaptic vesicles and pineal SLMVs. RNA interference of sialin expression decreased exocytosis of aspartate and glutamate in pinealocytes.
Asymptomatic cysts of the pineal region are common incidental findings in adults. In contrast, symptomatic pineal cysts are rare and their management is not well defined. The MR images showed a voluminous cyst of the pineal region responsible for an obstructive hydrocephalus. Reviewing the literature demonstrates that the endoscopic approach represents a minimally invasive and safe procedure in the treatment of symptomatic pineal cysts..
Dab2 protein was also identified within circumventricular organs including the choroid plexus, subcommissural organ and pineal gland during their early development. While Dab2 was still strongly expressed in the adult choroid plexus, immunoreactivity within the subcommissural organ and pineal gland was lost after birth.
Melatonin is not only synthesized by the pineal gland but also in many other organs and tissues of the body, particularly by lymphoid organs such as the bone marrow, thymus and lymphocytes.
In mammals, day-length-sensitive (photoperiodic) seasonal breeding cycles depend on the pineal hormone melatonin, which modulates secretion of reproductive hormones by the anterior pituitary gland [ 1]. In mammals this provides the missing link between the pineal melatonin signal and thyroid-dependent seasonal biology..
Melatonin is a powerful antioxidant agent secreted by the pineal gland which has numerous physiological functions and seems to exert an important neuroprotective effect.
Melatonin (N-acetyl-5-methoxytryptamine) is synthesized and released by the pineal gland following a circadian rhythm characterized by high levels during the night.
OBJECTIVE: To study whether Danggui Shaoyao Powder (DSP) is by way of improving pineal function to realize its anti-aging effects. METHODS: Forty aged rats were randomly divided into the sham operated group (A), the pinealectomized group (B), the sham medicated group (C), the pinealectomized and medicated group (D). Since its effects reduced after pinealectomy, it could be deduced that improving pineal function should be one of the action mechanisms for anti-aging..
The pineal and pituitary-adrenocortical secretions play an important role in adaptive responses of the organism acting as coordinating signals for both several biological rhythms and multiple neuroendocrine and metabolic functions.
To look for a relationship between pineal function in chronic migraine (CM), cluster headache (CH) (during active and remission periods), chronic tension-type headache (CTTH) patients and controls during NREM sleep, REM sleep and waking, we performed serial sampling of plasma melatonin in the different sleep stages during the first half of the night, in order to avoid chronobiological interferences.
Photoreceptor cells in the fish pineal gland transduce light-dark information differentially into a neuroendocrine melatonin message; distinguishing features are the presence or absence of endogenous oscillators that drive these rhythms. In the present study, we have analysed the presence and distribution of nitric oxide (NO) synthase in both pineal types by NADPH-diaphorase (NADPHd) histochemistry and determined the effects of NO donors on cGMP formation and melatonin production. NADPHd staining was confined to photoreceptor cells in clock-driven pineal organs of zebrafish and goldfish as evidenced by a codistribution with S-antigen-immunoreactivity (-ir) or cyclic GMP-ir and, in the pineal of the trout, to cells that are S-antigen negative. In the trout pineal, but not in the other species, NADPHd staining was clearly codistributed with growth associated protein-43 (GAP-43) immunoreactivity, an antibody that recognizes developing and regenerating neurons in the fish brain. The presence of a functional NO system in photosensory pineal organs is supported by the fact that NO donors like S-nitroso N-acetylpenicillamine (SNAP) elevate intracellular cGMP levels. However, despite the significant rise in cGMP levels nitric oxide donors did neither affect acute light-dependent melatonin formation in the trout pineal nor the rhythmic production of melatonin in the zebrafish pineal..
The data about pineal hormone melatonin influence on cardiovascular system of the people and animals were summarized.
However, this chief secretory product of the pineal gland is now recognized to also exert numerous additional functions which range from free radical scavenging and DNA repair via immunomodulation, body weight control and the promotion of wound healing to the coupling of environmental cues to circadian clock gene expression and the modulation of secondary endocrine signalling (e.g. Recently, it was shown that mammalian (including human) skin and hair follicles are not only melatonin targets, but also sites of extrapineal melatonin synthesis.
We describe a patient with a recurrent germinoma 14 years after radiotherapy of a pineal tumour.
A 20-year-old male with a solitary intradural extramedullary spinal metastasis from a pineal germinoma presented with progressive spinal cord compression.
Approximately 300 cases of primary meningeal melanoma have been reported in the literature;(1) eight of these cases had an associated pineal melanoma without additional parenchymal lesions.(2) We present another such case and demonstrate the advantage of magnetic resonance imaging over computed tomography in the early detection of meningeal involvement..
The present study was conducted to determine the effects of basal, isotonic as well as hypertonic and hypovolemic treatments on fluid-electrolyte balance and plasma AVP levels in rats supplemented with L-thyroxine and pinealectomized L-thyroxine. The animals were initially separated into 4 groups: control (n = 24), L-thyroxine treated (n = 24); L-thyroxine + sham-pinealectomy (n = 24) treated and 4-L-thyroxine + pinealectomy (n = 24) treated. However, this increase was depicted to be significantly more prominent in L-thyroxine + pinealectomy treated group (P <0.001). The results of the present study indicate that L-thyroxine treatment increases the basal and stimulated AVP release, which became more significant in the pinealectomy plus L-thyroxine treatment group. Moreover, the results indicate that AVP response to hypertonic and hypovolemic stimulations does not undergo any change due to supplementation by L-thyroxine treatment and/or pinealectomy plus L-thyroxine..
MRI study revealed in the left internal acoustic meatus mass (7 x 7 x 14 mm) suggesting acoustic neuroma and an oval mass (7 x 9 x 14 mm) in the pineal gland presenting radiological features of pinealoma. Acoustic neuroma has been removed by suboccipital approach and pinealoma has been left for further observation as it was found incidentally.
Although CT revealed a the reduction in multiple lung metastases, CEA was increased to over a maximum 109, high fever continued and the pinealtumor was enlarged in December 2006. The pineal pain and pineal discharge disappeared, so the quality of life has improved dramatically..
The pineal complex of zebrafish consists of a pineal organ and a left-sided parapineal organ. Mutation of the floating head (flh) gene, which encodes a homeodomain protein, causes premature termination of pineal cell division without affecting specification or asymmetric placement of the parapineal. The from beyond (fby) mutation, a premature stop codon in the T-domain-containing protein Tbx2b, disrupts formation of the parapineal while leaving the pineal largely intact. We conclude that Flh and Tbx2b regulate separate programs of pineal and parapineal development.
The pineal gland is the circadian oscillator in the chicken, regulating diverse functions ranging from egg laying to feeding. Here, we describe the isolation and characterization of expressed sequence tags (ESTs) isolated from a chicken pineal gland cDNA library. Here, we have described resources that may be useful in comparative and functional genomic analysis of genes expressed in an important organ, the pineal gland, in a model and agriculturally important organism..
However, whether and how changes in light and food stimuli affect circadian rhythms of mammalian pineal clock genes are still largely unknown. For the first time, in the present study, we established a method for analysis of the expression levels of most clock genes (Bmal1, Per1, Per2, Per3, Cry1, Dec1 and Dec2) and AANAT in a single rat pineal gland and used it to investigate individual and cooperative effects of feeding and light cycle reversals on the pineal circadian system. Feeding reversal (RF) alone for 7 days had only weak effect on the rhythmicity of clock gene expression in the pineal gland, whereas light/dark reversal for the same period without any change in the feeding regime could not absolutely reverse the expression phases of all examined genes either. However, reversal of the LD cycle together with the feeding regime completely resynchronized the circadian gene expression in the pineal gland within 7 days. These data suggest that photic regulation is the dominant cue that synchronizes the pineal circadian rhythm more efficiently than the feeding-related cue, but food availability does contribute to reentrainment of the pineal circadian system. In addition, the inability of RF in the pineal circadian system suggests that the pineal gland is more strongly coupled to the master clock than other peripheral organs and alternatively distinguishes it from other peripheral organs in the hierarchically organized mammalian circadian systems..
For further analysis of the interactions between melatonin and insulin, diabetic rats were investigated with respect to melatonin synthesis in the pineal gland and plasma insulin levels. Furthermore, the mRNA of pineal insulin receptors and beta1-adrenoceptors, including the clock genes Per1 and Bmal1 and the clock-controlled output gene Dbp, increases in both young and middle-aged STZ rats.
The photoperiodic information is transmitted to the reproductive system by melatonin, a pineal hormone whose secretion is adjusted to night length. The inhibition of Kiss1 expression in short photoperiod is driven by melatonin because pinealectomy prevents decrease in Kiss1 mRNA level in short photoperiod and melatonin injection in long photoperiod down regulates Kiss1 expression.
The significance of histological diagnosis was retrospectively investigated in the treatment of 79 consecutive patients with pineal region tumours. Forty-one patients were treated under a clinical diagnosis of pineal germ cell tumour using neoadjuvant chemotherapy and radiation therapy without histological verification. Most cases of pineal germ cell tumour could be identified on the basis of clinical findings only, and could be treated appropriately using neoadjuvant chemotherapy and radiation therapy without histological diagnosis.
The enterochromaffin cells of the gastrointestinal (GI) tract secrete 400 times as much melatonin as the pineal gland; therefore, it is not surprising that research is finding that this indole plays an important role in GI functioning.
In experimental conditions, the biological toxicity of irradiation appeared to be reduced by antioxidant agents, such as pineal hormones melatonin. A preliminary study was conducted to evaluate the influence of different immunobiological strategies with pineal indoles melatonin (MLT), 5 methoxytriptamine (5-MTT) or low-dose IL-2, the lymphocyte growth factor, on pelvic irradiation-induced lymphocytopenia in cancer patients suffering from rectal cancer or uterine cervix carcinoma.
Suprachiasmatic nucleus of the hypothalamus and the pineal gland ensure that sleep and wakefulness follow a circadian periodicity of nearly 24 hours.
Melatonin (N-acetyl-5-methoxytryptamine) is the chief secretory product of the pineal gland and synthesized enzymatically from serotonin (5-hydroxytryptamine).
Melatonin is secreted by the pineal gland and this is linked to the day/night cycle.
Although the fetal pineal gland does not secrete melatonin, the fetus is exposed to melatonin of maternal origin.
The vertebrate pineal organ has a conserved role in circadian regulation as the primary source of the nocturnal hormone melatonin. In lower vertebrates, the pineal has an endogenous circadian clock as well as photoreceptive cells that regulate this clock. The zebrafish opsin protein Exo-rhodopsin (Exorh) is expressed in pineal photoreceptors and is a candidate to mediate the effects of environmental light on pineal rhythms and melatonin synthesis. We demonstrate that Exorh has an important role in regulating gene transcription within the pineal. This suggests that the Exorh protein at the cell membrane is part of a signaling pathway that positively regulates transcription of these genes, and ultimately melatonin production, in the pineal. This work identifies novel roles for Exorh and Per3, and gives insight into potential interactions between the sensory and circadian systems within the pineal..
The primary conductor of circadian rhythms of birds is the pineal gland. The presence of PACAP has been demonstrated both in the rat and avian pineal gland, where PACAP stimulates melatonin synthesis. The signaling mechanism, by which PACAP modulates melatonin synthesis and circadian rhythmic functions of the pineal gland, is only partially known. The aim of the present study was to investigate the effects of PACAP on the changes of p38 mitogen-activated protein kinase (MAPK) and 14-3-3 protein in chick pineal cell culture both of which have been shown to participate in the regulation of rhythmic functions. pineal cells were treated with 1, 10, or 100 nM PACAP38 every 4 h during a 24-h period. In summary, PACAP modulated the phosphorylation of p38 MAPK and the appearance of 14-3-3 protein in the chicken pineal cells, but these effects were dose dependent and also depended on the time of day..
The authors report a metachronous germ cell tumor with different histological type occurring 12 years after resection of a pineal germinoma.
CNS GCTs are most commonly located in the pineal and suprasellar regions of the brain and can be divided into major groups including germinomas and nongerminomatous GCTs (NGGCTs), with teratomas often considered a separate category.
OBJECTIVES: The purpose of this study is to investigate if the aqueous extract of the Chinese medicine Danggui-Shaoyao-San (DSS) can increase the plasma level of melatonin and enhance the function of the pineal gland of naturally aged rats. The function of pineal gland were measured through three parameters: pineal beta adrenergic receptor binding investigated by [ 3H]DHA binding; pineal expression of NAT mRNA detected by real-time RT-PCR; phosphorylation of CREB (P-CREB) and total level of CREB (T-CREB) measured by western blot analysis. By measurement of pineal [ 3H]DHA binding, it was found DSS improved the beta-adrenergic receptors binding in pineals. The stimulatory effect of DSS on the expression of NAT mRNA in the old rat pineal gland has been demonstrated in this study. CONCLUSIONS: Our results indicate that a downstream pathway for DSS induction of melatonin synthesis in the rat pineal gland acts via cyclic AMP-dependent cascade and transcription mechanism..
The authors report the case of a 16-year-old male who presented with a bifocal diencephalic tumor arising both in the neurohypophysis and the pineal region with hydrocephalus.
We report the fourth case of a primary germ cell tumor occurring after the treatment of a primary CNS germ cell tumor in a 27 year-old male with embryonal cell carcinoma of the testicle 9 years after the treatment of a germ cell tumor of the pineal gland.
Myosin-Va is highly expressed in the pineal and pituitary glands and in specific cell populations of other endocrine glands, especially the parafollicular cells of the thyroid, the principal cells of the parathyroid, the islets of Langerhans of the pancreas, the chromaffin cells of the adrenal medulla, and a subpopulation of interstitial testicular cells.
Three cannulae were placed in the supraoptic, infundibular, and pineal recesses of the third ventricle. GnRH pulses were detected in all ewes in infundibular recess CSF, but at sites more rostral (supraoptic) and caudal (pineal), GnRH pulse frequency and amplitude significantly (P<0.05) decreased.
In hypothalamus there was a significant peak at 22:00 and two minor peaks at 17:00 and 02:00 h; the same occurred in hippocampus with a significant peak at 21:00, and two secondary peaks at 24:00 and 05:00 h; in cerebellum there were two peaks at 21:00 and 02:00 h, while in striatum and pineal there were peaks at 21:00 h and 23:00, respectively.
In the mammalian pineal gland, the rhythm in melatonin biosynthesis depends on the norepinephrine (NE)-driven regulation of arylalkylamine N-acetyltransferase (AANAT), the penultimate enzyme of melatonin biosynthesis. A recent study showed that phytocannabinoids like tetrahydrocannabinol reduce AANAT activity and attenuate NE-induced melatonin biosynthesis in rat pineal glands, raising the possibility that an endocannabinoid system is present in the pineal gland. To test this hypothesis, we analyzed cannabinoid (CB) receptors and specific enzymes for endocannabinoid biosynthesis or catabolism in rat pineal glands and cultured pinealocytes. Immunohistochemical and immunoblot analyses revealed the presence of CB1 and CB2 receptor proteins, of N-acyl phosphatidyl ethanolamine hydrolyzing phospholipase D (NAPE-PLD), an enzyme catalyzing endocannabinoid biosynthesis and of fatty acid amide hydrolase (FAAH), an endocannabinoid catabolizing enzyme, in pinealocytes, and in pineal sympathetic nerve fibers identified by double immunofluorescence with an antibody against tyrosine hydroxylase. The immunosignals for the CB2 receptor, NAPE-PLD, and FAAH found in pinealocytes did not vary under a 12 hr light:12 hr dark cycle. The CB1 receptor immunoreaction in pinealocytes was significantly reduced at the end of the light phase [ zeitgeber time (ZT) 12]. The immunosignal for NAPE-PLD found in pineal sympathetic nerve fibers was reduced in the middle of the dark phase (ZT 18). Stimulation of cultured pinealocytes with NE affected neither the subcellular distribution nor the intensity of the immunosignals for the investigated CB receptors and enzymes. In summary, the pineal gland comprises indispensable compounds of the endocannabinoid system indicating that endocannabinoids may be involved in the control of pineal physiology..
Like enucleation, lateral hypothalamic (LH) lesions sever the connection between the retina and the pineal thereby simulating ambient exposure to constant darkness.
Analysis of the study results shows that the administration of Epithalamin pineal gland peptide medication to middle-aged and elderly women with ischemic heart disease and arterial hypertension improves lipid metabolism and reduces the diurnal arterial pressure level, thus decreasing the risk of fatal cardiovascular complications..
In order to define the functional morphology of the pineal gland (epiphysis) and to reveal extrapineal sources of melatonin (MT) during human aging, biopsy samples obtained from 175 male persons aged 16 to 84 were examined.
In order to reveal the participation of extrapineal melatonin in ageing processes, Wistar rats were (a) exposed to small doses of gamma irradiation and (b) subjected to pinealectomy. During pinealectomy the number of MT-positive enterochromaffin cells increases..
Morphological changes that take place in the epiphysis in the course of age involution are inseparably associated with a drastic decrease in the synthesis of melatonin (MT) - the main hormone of the pineal gland that coordinates biorhythms of the body at all system levels. The pineal gland is not the only organ able producing MT Multiple research have proved that the extrapineal MT is also widely present in human and animal organism.
An important corollary was the finding that antidepressant drugs acted as inhibitors of this uptake process.Subsequent work in his laboratory on the control of melatonin biosynthesis in the pineal gland provided new insights into the way in which the nervous system controls circadian rhythms, and offered an early model system in which to study the rapid control of mammalian gene expression.
Light at night has two major physiological actions, i.e., it disrupts circadian rhythms and suppresses the production of melatonin by the pineal gland.
Among these and discussed herein are (i) the nosologic place of highly anaplastic oligoastrocytic tumors, (ii) the forms and significance of microvascular changes in high-grade gliomas, (iii) the makeup of the glioneuronal tumors category, (iv) the subclassification of pineal parenchymal tumors of intermediate type, and (v) the classification of principle forms of mesenchymal neoplasms, specifically hemangiopericytoma and solitary fibrous tumor.
This study was undertaken to explore the anatomic features and adjacent relationships of the pineal region in thin coronal sections. Subsequently, the anatomic structures of the pineal region on the thin coronal sections were investigated and correlated with in vivo MR images, which were obtained from ten normal Chinese male adult volunteers by a 3.0 T GE scanner. A total of 355 coronal sections and 21-23 in vivo coronal MR images related with the pineal region were obtained, respectively. From anterior to posterior, the shape of the pineal region changed from an inverted triangle to a trapezoid and a triangle gradually, and the anatomic details could be depicted clearly in the thin sectional anatomy images in sub-millimeter. Via the comparison, some micro-anatomic structures of the pineal region that cannot be discriminated clearly or missed in the thick sections or MR images were identified. The contrast of the computerized freezing milling technique with the MRI enhanced our ability to comprehend the complex anatomy of the pineal region and to improve the imaging diagnosis and surgical treatments of minute diseases in this region..
Pretreatment with either S-methylisothiourea (S-MT), a selective iNOS inhibitor, or melatonin, a major secretory product of pineal gland, counteracted the over expression of iNOS induced by AMPH in a concentration-dependent manner.
SRs occur not only in neurons, but also in neuroendocrine pinealocytes where their function is still obscure. In this study, we report that pinealocyte SRs are associated with CAZ proteins such as Bassoon, Piccolo, CtBP1, Munc13-1, and the motorprotein KIF3A and, therefore, consist of a protein complex that resembles the ribbon complex of retinal and other sensory ribbon synapses. The pinealocyte ribbon complex is biochemically dynamic. The diurnal dynamics of the ribbon complex persist under constant darkness and decrease after stimulus deprivation of the pineal gland by constant light. Our findings indicate that neuroendocrine pinealocytes possess a protein complex that resembles the CAZ of ribbon synapses in sensory organs and whose dynamics are under circadian regulation..
The new WHO classification introduces 7 changes in the grading of central nervous system neoplasms, ranging in significance from minor to major, in categories of anaplastic oligoastrocytomas, meningiomas, choroid plexus tumors, pineal parenchymal tumors, ganglioglioma, cerebellar liponeurocytoma, and hemangiopericytomas.
The aim of this work is to determine the mechanisms by which melatonin, a hormone produced in the brain by the pineal gland, inhibits the catalytic activity of EPO.
The frequent origin sites are mediastinum, retroperitoneum, sacrococcygeal region, and the pineal gland.
BACKGROUND: Anticancer immunity is under psychoneuroendocrine regulation, mainly via the pineal gland and brain opioid system, which may stimulate and inhibit antitumor immunity respectively. Cancer-related immuno-suppression does not depend only on functional damage of immune cells, but also on alterations of systems responsible for the neuroimmunomodulation, the most frequent of wich is a decline in blood levels of the pineal hormone melatonin (MLT). CONCLUSION: The administration of IL-2 and the pineal hormone MLT may induce control of neolplastic growth and a prolonged survival time in patients with metastatic solid tumors, for whom no other conventional anticancer therapy is available..
The results suggest that the function of nigral cells is regulated by a more global system embracing circadian physiology that extends from the retina to the pineal.
It is produced by the pineal gland and within the retina; its release is blocked by light entering the eye.
Effects of morning and evening injections of pineal 5-methoxyindoles (MI), melatonin (aMT) and 5-methoxytryptamine (MT), for 60 continuous days, were observed on the testes of sham-operated (SO) and pinealectomized (Px) Indian palm squirrel, Funambulus pennanti maintained under different photoperiods during the gonad active phase.
The duration of nocturnal pineal melatonin secretion transduces effects of day length (DL) on the neuroendocrine axis of photoperiodic rodents. In most photoperiodic species, pinealectomy does not diminish reproductive competence in long DLs. Turkish hamsters (Mesocricetus brandti) deviate from this norm: elimination of melatonin secretion in long-day males by pinealectomy or constant light treatment induces testicular regression and subsequently recrudescence; the time course of these gonadal transitions is similar to that observed in males transferred from long to short DLs. Other hamsters that manifested testicular regression and recrudescence in short DLs were unresponsive to the antigonadal effects of pinealectomy or constant light.
Melatonin is a neuroendocrine hormone secreted nightly by pineal gland and regulates biological rhythms.
PATIENTS AND METHODS: Fifteen children aged <18 years with non-pineal sPNETs diagnosed between 1992 and 2006 were identified.
Melatonin, the main product secreted by the pineal gland has oncostatic properties.
In the present study, we designed a strategy of ex vivo pretreatment with the pineal hormone melatonin to improve survival, paracrine activity, and efficiency of MSCs.
The pineal gland of zebrafish (Danio rerio) contains light-sensitive photoreceptor cells and plays an important role in the neuroendocrine system. The zebrafish exorhodopsin gene encodes a pineal-specific photoreceptive protein, whose promoter region harbors a cis-acting element, pineal expression-promoting element (PIPE), directing pineal-specific gene expression. In Tg(P(20)-rh/P:gfp) fish, PIPE-dependent gene expression is visualized by GFP fluorescence in the pineal gland along with PIPE-independent GFP signals in the retinal rod photoreceptors. The transgenic fish exhibit detectable and reproducible GFP fluorescence in the larval pineal gland by 5 days postfertilization. Antisense morpholino-mediated knock-down of a pineal transcription factor gene, otx5, suppresses pineal GFP expression in the transgenic line. In a pilot screen of N-ethyl-N-nitrosourea-treated fish of the GFP transgenic line, we isolated potential dominant mutations that cause attenuation of pineal GFP fluorescence with a marginal effect on the retinal GFP signal. The results suggest that the Tg(P(20)-rh/P:gfp) line will be useful for detecting deficits in PIPE-dependent gene expression in the pineal gland..
Melatonin synthesis in the retina as well as in the pineal gland exhibits daily variations with higher levels during the dark phase of light-dark cycles.
The body color of surgeonfish shows circadian changes, and becomes paler at night; this effect may be mediated by the pineal hormone, melatonin, which aggregates pigment in melanophores..
In this paper the authors report a novel use of this device in the assessment of papilledema in a patient with pilocytic astrocytoma of the pineal region. An 11-year-old girl presented with headache and bilateral papilledema; magnetic resonance imaging revealed a lesion in the pineal region.
BACKGROUND: Chick pinealocytes exhibit all the characteristics of a complete circadian system, comprising photoreceptive inputs, molecular clockworks and an easily measured rhythmic output, melatonin biosynthesis. These properties make the in vitro pineal a particularly useful model for exploring circadian control of gene transcription in a pacemaker tissue, as well as regulation of the transcriptome by primary inputs to the clock (both photic and noradrenergic). RESULTS: We used microarray analysis to investigate the expression of approximately 8000 genes within cultured pinealocytes subjected to both LD and DD. CONCLUSION: Our combined approach of utilizing a temporal, photic and pharmacological microarray experiment allowed us to identify novel genes linking clock input to clock function within the pineal. We identified approximately 30 rhythmic, light-responsive, NE-insensitive genes with no previously known clock function, which may play a role in circadian regulation of the pineal. Further, we hypothesize that the pineal circadian transcriptome is reduced but functionally conserved in vitro, and supports an endogenous role for the pineal in regulating local rhythms in metabolism, immune function, and other conserved pathways..
This article analyzes the effect of a high-fat diet (35% fat) on 24-h changes circulating prolactin, luteinizing hormone (LH), testosterone, corticosterone, thyroid-stimulating hormone (TSH) and glucose, and pineal melatonin content, in rats. The amplitude of the nocturnal pineal melatonin peak decreased significantly in high-fat fed rats.
Biosynthesis and metabolism of serotonin and catecholamines involve at least eight individual enzymes that are mainly expressed in tissues derived from the neuroectoderm, e.g., the central nervous system (CNS), pineal gland, adrenal medulla, enterochromaffin tissue, sympathetic nerves, and ganglia.
This review summarizes the most relevant data relating to the potential role of melatonin (pineal secretory product) as an adjuvant therapy of tumors. Most of the reports unequivocally confirmed the antioxidative and immunostimulatory action of the pineal secretory product in both in vitro and in vivo experiments.
Whereas most teratomas occur in the ovaries and testes of adolescents, they can be found in midline structures such as sacrococcygeum (congenitally), anterior mediastinum, retroperitoneum, and the pineal gland.
The pineal hormone melatonin may affect the sleep characteristics.
Melatonin, the main secretary product of the pineal gland, is potentially effective in the prevention of a number of diseases in which free radical processes are involved.
In adults, primary intracranial tumours causing DI include craniopharyngioma, or pineal tumours.
OBJECTIVE: Accepted surgical strategies to address symptomatic pineal cysts include transventricular flexible or rigid endoscopy and supracerebellar infratentorial or occipital transtentorial microsurgical approaches. We report the first application of the endoscopic supracerebellar infratentorial approach for the complete resection of a pineal cyst. A thorough evaluation revealed only a pineal cyst exerting mass effect on the tectum but causing no hydrocephalus. The pineal cyst was resected completely via the endoscope. Consequently, it is an excellent minimally invasive surgical option for resection or fenestration of symptomatic pineal cysts..
The possible mechanisms of the effects of external magnetic stimulation on the pineal gland in the brain are presented..
Various evidence has documented that the pineal secretory product melatonin exerts an important anti-inflammatory effect in different experimental models including colitis.
The goal of this cross-sectional observational study was to determine the incidence of pineal gland calcification (PGC), to investigate the interaction of PGC and aging, and to compare the incidence of PGC among the populations living in Turkey. This study provides some reference data for new clinical studies on the putative role of pineal gland in future..
Nonmammalian vertebrates use photoreceptors located deep in the brain and in the pineal gland as well as others in the retina.
RORbeta expression is largely restricted to several regions of the brain, the retina, and pineal gland.
INTRODUCTION: Pineoblastomas are a category of supratentorial primitive neuroectodermal tumors (sPNETs) occurring in the pineal gland; some studies support the impression that patients with pineoblastomas have a worse prognosis than those with other sPNETs.
Descartes intuitively anticipated the so-called 'binding problem' of consciousness and thought that the pineal gland enables spatio-temporal integration in cognitive processing. Recent findings indicate that a major role in the process of temporal integration and binding involve neurons in suprachiasmatic nuclei, specifically targeting the pineal gland and other structures, and control the neuroendocrine rhythms.
The highest activity was measured in the choroids plexus and the pineal gland.
Neuroepithelial papillary tumor of the pineal region (PTPR) has been described by several groups and recognized by the 2007 World Health Organization Classification of Tumors of the Central Nervous System.
Isolated pathology, such as a calcification of the pineal gland and focal demyelination of vascular origin were detected in individual children.
Our previous studies showed that neurotoxicity induced by AMPH was mediated by enhanced oxidative stress and these effects were abolished by melatonin, a main secretory product of pineal gland.
Several phenotypic features are common to this syndrome, including severe hyperinsulinemia, growth retardation, acanthosis nigricans, dental dysplasia, hirsutism, coarse facial features, and pineal hyperplasia.
The pineal neuroindole, melatonin, reduces the affinity of glucocorticoid receptors in rat brain and prevents glucocorticoid-induced apoptosis.
Pineoblastomas are uncommon pineal tumors, which demonstrate rapid growing and poor prognosis. We report the case of a 43-year-old man with an enhancing pineal region mass, which showed restriction of the diffusion on diffusion-weighted (DW) MR images. The differential diagnosis of pineal region masses that could show restriction of diffusion is discussed..
INTRODUCTION: Tumours in the pineal region are rare (0.3-2.7%) and most of the ones that do occur are germ cell tumours, of which germinoma is the most frequent. They are chiefly located in the pineal gland, the next most common being site being the suprasellar region and the fourth ventricle, although simultaneous presentation in these locations is relatively rare (5-10% of cases). The main aim of this study is to review the differential diagnosis of neoplasias in the pineal region. Magnetic resonance imaging of the craniospinal axis was performed and results showed the presence of two masses with significant enhancement, one located in the pineal region with a signal similar to that of grey matter and the other in the hypothalamus, which had a more heterogeneous aspect with cystic areas inside it.
By studying the zebrafish pineal complex, which exhibits notable asymmetries, both the genes and the cell movements that result in left-right differences can be characterized. The pineal complex consists of the midline pineal organ and the left-sided parapineal organ. The parapineal is responsible for instructing the asymmetric architecture of the bilateral habenulae, the brain nuclei that flank the pineal complex. Using in vivo time-lapse confocal microscopy, we find that the cells that form the parapineal organ migrate as a cluster of cells from the pineal complex anlage to the left side of the brain. In a screen for mutations that disrupted brain laterality, we identified a nonsense mutation in the T-box2b (tbx2b) gene, which encodes a transcription factor expressed in the pineal complex anlage. The tbx2b mutant makes fewer parapineal cells, and they remain as individuals near the midline rather than migrating leftward as a group. The reduced number and incorrect placement of parapineal cells result in symmetric development of the adjacent habenular nuclei. We conclude that tbx2b functions to specify the correct number of parapineal cells and to regulate their asymmetric migration..
The regulatory influence of the pineal gland on superficial wound healing and collagen content is documented. The aim of the present study was to determine whether the pineal gland and its secretory product melatonin regulate collagen accumulation in the scar of the infarcted heart and to explain the mechanisms of its action. pinealectomy was performed on some animals. Surgical and pharmacological pinealectomies had opposite effects and reduced collagen content in the scar. However, melatonin administration (60 microg/100 g b.w.) to pinealectomized rats reversed the effect of pinealectomy and normalized collagen levels in heart after infarction.
In investigations carried out with organotypic culture of mediobasal preoptic area (MPA) of hypothalamus it was established that pineal peptide preparations epitalon (2 ng/ml) and epithalamin (100 ng/ml) stimulate the development of proliferative activity of explants in 3 month and 24 months female rats.
To estimate the sign and measure of changes of the pineal gland volume in perimenopausal period a magnetic-resonance tomography studies of the head of men (n=72) and women (n=74) of 38-61-year old were organized, in group divided into two subgroups with a space of 2 years. For estimation of possible dependency of the pineal gland volume on the reproductive cycle phase the similar study was organized in groups of women of the first (n=34) and second mature age (n=41) with regular cycle who were divided into subgroups by the phase of the cycle fixed retrospectively by the basal temperature graphs. The valid reduction of the pineal gland volume was registered in women of ovulate phase as well as during perimenopausal period. In context of literary data concerning recurrence and age dynamic of melatonin production by the pineal gland participation of pineal gland in "shutdown" of reproductive functions in women is supposed..
By reviewing our cases and previous reports, we describe 4 neuronal and mixed neuronal-glial tumors (papillary glioneuronal tumor, extraventricular neurocytoma, rosette-forming glioneuronal tumor of the fourth ventricle, and glioneuronal tumor with neuropil-like islands), angiocentric glioma and papillary tumor of the pineal region, with an attempt to explain the pathological basis of the imaging features..
pineal MEL, which was affected by the photic condition, may play an important role in the secretory rhythm of GH secretion in cattle..
We present a 48-year-old man who developed an oligodendroglial tumor 38 years after receiving 50 Gy of cranial irradiation to a pineal tumor.
Cytologic pleomorphism has been described in a limited number of benign pineal tumors, namely pineocytoma (PC) and pineal parenchymal tumors (PPTs) of intermediate differentiation (PPTID).
OBJECTS: The goal of the study was to establish if endoscopic biopsy during third ventriculostomy contributes to morbidity in the management of paediatric pineal region tumours presenting with hydrocephalus. MATERIALS AND METHODS: This study was a retrospective descriptive study in patients less than 18 years of age who have presented with a pineal region tumour between 2000 and 2006. Twelve patients had presented with a pineal region mass with symptomatic hydrocephalus. Endoscopic biopsy during third ventriculostomy in paediatric pineal region tumours is safe and results in good diagnostic yields.
Melatonin was initially extracted from the pineal gland and was thought to be produced exclusively by this organ. Over the last thirty years, a great number of reports have documented a relationship between melatonin/pineal gland and the immune system in various species, including humans.
Melatonin, the hormone of the pineal gland, received recently a great deal of attention because of its suggested role in aging processes and availability as over-the-counter drug or food supplement in some countries, including Poland.
The gastrointestinal tract represents the most important extra pineal source of melatonin.
Melatonin, known as a product of pineal gland is also produced in the digestive system.
Melatonin, the main product of the pineal gland, is also released from the gastrointestinal endocrine-neurocrine (EE) cells.
Melatonin, a major hormone of pineal gland, whose activity is also abundant in the gastrointestinal tract, was shown to inhibit gastric acid secretion, augment GBF and scavenge free radicals, resulting in the attenuation of stress-induced gastric lesions. Using rats with intact pineal glands and those with removed pineal glands (pinealectomy) exposed to water immersion and restraint stress (WRS) at both, day and night hours, we studied the effect of light and nocturnal melatonin on the formation of these lesions, and accompanying changes in GBF and plasma melatonin levels. pinealectomy augmented WRS-induced lesions at each time intervals of WRS and produced a marked fall in the GBF and plasma and luminal melatonin levels at each time interval of WRS tested. WRS-induced gastric mucosal lesions were markedly enhanced in pinealectomized rats, both at day and night, and this was accompanied by a significant fall in plasma melatonin levels Stress that appears as a consequence of burns, surgical trauma and life threatening conditions is a serious clinical entity, can result in acute gastric mucosal lesions. Melatonin, a major hormone of pineal gland, whose activity is also abundant in the gastrointestinal tract, was shown to inhibit gastric acid secretion, augment GBF and scavenge free radicals, resulting in the attenuation of stress-induced gastric lesions. Using rats with intact pineal glands and those with removed pineal glands (pinealectomy) exposed to water immersion and restraint stress (WRS) at both, day and night hours, we studied the effect of light and nocturnal melatonin on the formation of these lesions, and accompanying changes in GBF and plasma melatonin levels. pinealectomy augmented WRS-induced lesions at each time intervals of WRS and produced a marked fall in the GBF and plasma and luminal melatonin levels at each time interval of WRS tested. WRS-induced gastric mucosal lesions were markedly enhanced in pinealectomized rats, both at day and night, and this was accompanied by a significant fall in plasma melatonin levels with a pronounced reduction in mucosal generation of PGE(2) and GBF and by a small increase in plasma melatonin levels during the dark phase. We conclude that 1) stress-induced gastric bleeding erosions exhibit circadian rhythm with an increase in the day and attenuation at night and that these fluctuations in the formation of stress-induced gastric damage may depend upon the melatonin synthesis 2) the progressive increase in plasma melatonin in pinealectomized animals exposed to various time intervals of WRS suggests that extra-pineal melatonin possibly that derived from gastrointestinal tract, play an important role in the gastric mucosal defense against stress-induced gastric damage..
The biosynthetic steps of melatonin with two major rate limiting enzymes, arylalkylamine-N-acetyltransferase (AA-NAT) and hydroxyindole-O-methyltransferase (HIOMT), transforming tryptophan to melatonin, originally identified in pinealocytes have been also detected in entero-endocrine (EE) cells of GIT wall, where this indole may act via endocrine, paracrine and/or luminal pathway through G-protein coupled receptors. Melatonin in GIT was shown to be generated in about 500 times larger amounts than it is produced in pineal gland. The production of melatonin by pineal gland shows circadian rhythm with high night-time peak, especially at younger age, followed by the fall during the day-light time. Following pinealectomy, the light/dark cycle of plasma melatonin levels disappears, while its day-time blood concentrations are attenuated but sustained mainly due to its release from the GIT. After oral application of tryptophan, the plasma melatonin increases in dose-dependent manner both in intact and pinealectomized animals, indicating that extrapineal sources such as GIT rather than pineal gland are the major producers of this indole.
pineal AANAT activity increases at night in all vertebrates, resulting in increased melatonin production.
Tumors were located as follows: pineal region (10 cases), hypothalamus (eight cases), basal ganglia (one case) and corpus callosum (one case). Six were bifocal (pineal region and hypothalamus).
BACKGROUND: Patients with pineal lesions typically present with the classical signs of increased intracranial pressure (headache, nausea, vomiting) and/or Parinaud's syndrome. Rare symptomatology of secondary parkinsonism attributed to pineal lesions has been previously reported in the literature. We describe an unusual case of a pineal cyst in a patient with the presenting sign of a resting tremor. Magnetic resonance imaging demonstrated an atypical appearance with enhancement of a mildly prominent pineal gland, possibly representing a pineal cyst. CONCLUSIONS: A new-onset, resting tremor and/or other secondary parkinsonism symptoms should raise clinical suspicions of pineal lesions.
Several other CNS tumor entities, including astroblastoma, chordoid glioma, papillary tumor of the pineal region, angiocentric glioma, and pilomyxoid astrocytoma, variably display histopathologic features of ependymal differentiation.
In its role as a pineal hormone, melatonin is a pleiotropic, nocturnally peaking and systemically acting chronobiotic. Regulation of pineal melatonin biosynthesis is largely explained by control mechanisms acting on arylalkylamine N-acetyltransferase, at the levels of gene expression and/or enzyme stability influenced by phosphorylation and interaction with 14-3-3 proteins. Melatonin is not only a hormone but is also synthesized in numerous extrapineal sites, in which it sometimes attains much higher quantities than in the pineal and the circulation.
Melatonin, an indole mainly synthesized in the pineal gland during the dark phase, plays a role as an endogenous antioxidant and an anticancer agent in many tumors.
A CT scan showed a SAH and enlargement of the pineal mass. pineal apoplexy should be considered as a cause of SAH..
To examine the source of circulating maternal melatonin, mRNA expression of N-acetyltransferase (NAT), which is a late limiting enzyme for melatonin synthesis, was examined in the placenta and fetal pineal. NAT was not expressed in the placenta and was negligible in the pineal gland of the fetus compared with the mother's pineal gland. In conclusion, maternal circulating melatonin is from the maternal pineal gland and is increased by placental hormones during pregnancy..
In all experiments, pineal and serum melatonin levels as well as the weights of testes, brain, kidneys, and liver were not affected.
In addition, we have measured the in vitro melatonin production of Arctic charr pineal glands held at experimental light conditions. The in vitro experiments revealed no endogenous rhythm in the pineal melatonin secretion, supporting the conclusion that the diel profile seen in the Arctic charr in their natural habitat was driven by ambient photoperiod.
Ganglioglioma may arise anywhere throughout the neuraxis including the optic nerve, brain stem, pineal gland, cerebellum, cerebrum and spinal cord; however, the majority of glioneuronal neoplasms involve the temporal lobe.
Melatonin, a pineal and gut secretory product, due to its antioxidant activity along with its effect on the aging gall bladder myocytes, inhibits gallstone formation.
OBJECTIVES: To report three children, two with medulloblastomas and one with a pineal germinoma, treated with radiotherapy that developed intracerebral cavernous hemangiomas some years after treatment.
Except for a pineal homolog, the amphioxus brain consists of a much simplified version of the ventral brainstem, including a region probably homologous with the hypothalamus, and a locomotory control center roughly comparable to the vertebrate tegmentum and reticulospinal system. Amphioxus has direct pathways for activating its locomotory circuits in response to mechanical stimuli via epithelial sensory cells, but this response is evidently modulated by inputs from diverse sensory-type cells located in the putative hypothalamic homolog, and from the lamellar body, the pineal homolog.
melatonin (MT) is a hormone produced by the pineal gland at night, involved in the regulation of circadian rhythms.
Melatonin, the chief secretory product of the vertebrate pineal gland is suspected to be a ubiquitous molecule principally involved in the transduction of photoperiodic information.
This study investigated the effect of maternal pinealectomy and postnatal pinealectomy on affective responses. Siberian hamsters were born to either pinealectomized or sham-operated dams and then underwent pinealectomy or a sham operation. Maternal pinealectomy increased depressive-like responses of offspring in the forced swim test. Maternal pinealectomy increased rearing behaviour and postnatal pinealectomy increased locomotor behaviour in the open field test.
The photoreceptive retina and the non-photoreceptive pineal gland are components of the circadian and the melatonin forming system in mammals. For this purpose, the 24-h profiles of the expression of the genes coding for arylalkylamine N-acetyltransferase (AA-NAT), nerve growth factor inducible gene-A (NGFI-A), nerve growth factor inducible gene-B (NGFI-B), retinoic acid related orphan receptor beta (RORbeta), dopamine D4 receptor, and period2 (Per2) have been simultaneously recorded in the retina and the pineal gland of rats under short day (light/dark 8:16) and long day (light/dark 16:8) conditions. The temporal phasing in the AA-NAT transcript amount between the retina and the pineal gland is retained under constant darkness suggesting that the intrinsic self-cycling clock of the retina oscillates in a phase-advanced manner with respect to the self-cycling clock in the suprachiasmatic nucleus, which controls the pineal gland. We therefore conclude that daily rhythms in gene expression in the retina are phase-advanced with respect to the pineal gland, and that the same temporal relationship appears to be valid for the self-cycling clocks influencing the tissues..
We present the rare case of a 31-year-old man who developed a germinoma 22 years after resection of a mature teratoma of the pineal region.
Results of a series of original investigations devoted to the antidepressant, anxiolytic, and nootropic activity of the pineal hormone melatonin are summarized.
The pineal hormone melatonin (0.1 mg/kg) produced a more pronounced antistressor effect as compared to the anxiolytic diazepam (same dose) in rats, which was manifested by decreased anxiety, improved heart rhythm variability, and prevented stress-induced violation of circadian locomotion.
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