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At least 37 records · Page 2Linked to original sources
PubMed1968

Enzymatic synthesis of melatonin in avian pineal body: extraretinal response to light.

In the chick pineal body, activity of the melatonin-forming enzyme hydroxyindole-O-methyl transferase is greater in the light than in darkness. Neither bilateral enucleation of the eyes nor sympathetic denervation prevented this light-induced elevation of enzyme activity. This fact indicates that in the bird, in contrast to mammals, neither the retinas nor sympathetic innervation of the pineal body are essential for environmental control of melatonin formation.

Animals↗
PubMed1976

Failure to demonstrate high concentrations of luteinising hormone-releasing hormone in the bovine pineal body.

Six in vitro experiments were conducted to study the effects of the incorporation into the culture system of 10 bovine pineal bodies (or a similar mass of bovine hypothalamic tissue) on the secretion of luteinising hormone (LH) from bovine adenohypophyseal tissue (anterior pituitary - AP). When hypothalamic tissue was incubated with AP tissue, an increased amount of LH was released into the medium but no marked increase in LH secretion was observed when pineal bodies were included in the AP culture system. Additionally, the amount of radio-immunologically active luteinising hormone-releasing hormone (LHRH) contained in bovine pineal bodies was much less than that contained in an equivalent mass of hypothalamic tissue. Thus, present results do not support the concept that the pineal body contains comparatively large amounts of lhrh.

Animals↗
PubMed1986

Retarded growth of the suprachiasmatic nucleus and pineal body in dw and lit dwarf mice.

The suprachiasmatic nucleus (SCN) and the pineal body in 3 types of inherited hormone-deficient mice, the dw, lit and hyt mice were examined by morphological, morphometric and biochemical techniques. In the dw and lit mice the SCN was underdeveloped. In the ventral part of the SCN, where most of the retinal fibers appeared to terminate, both cell number and cell size were decreased, although the size of the SCN was unaltered. In addition, the pineal bodies of both mice were morphologically underdeveloped and showed low levels of N-acetyltransferase activity. In contrast, the hyt SCN was comparable to the normal controls in every respect. The hyt pineal was well developed and showed levels of enzyme activity comparable to the controls. However, in all the deficient mice, the optic nerve appeared to be normal in morphological and biochemical studies. These results suggest that the underdevelopment of the pineal body, the reduced levels of spontaneous locomotion and the indistinct diurnal periodicity of the dw and lit mice might be related to the retarded neuronal growth of the SCN, and that growth hormone likely is indispensable for the development of the SCN.

Animals↗
PubMedDate not supplied

[Computer tomography in tumors of the posterior portions of the 3d ventricle and pineal body].

Computer tomography was applied in the examination of 72 patients with tumors in the posterior parts of the third ventricle and pineal body. Direct and indirect signs of tumors of this region were established. The direct signs are a zone of increased density in the region of the posterior parts of the third ventricle and the pineal body and total or partial tamponade of the lamina tecti cistern. Hydrocephalus of the ventricles and anterior parts of the third ventricle is an indirect sign. In 18 patients the CT pattern of the tumor was compared with its histological picture. It was found that a large homogeneous zone of rather high density with one or more petrifactions in the tumor tissue was more characteristic of malignant tumors (germinoma, pinealoma, anaplastic ependymoma). A small zone of nonhomogeneous relatively increased density with less frequently encountered calcifications was more typical of benign tumors (teratoma, pinealoma, ependymoma) of this region. The diagnosis of germinoma of the pineal body can often be made from the CT picture, in which case a very characteristic sign of "auricles" is demonstrated; it is caused by metastatic spread of the tumor to the subependymal layer of the anterior horns of the lateral ventricles. The role of CT in appraising the results of radiotherapy in tumors of the pineal body is shown.

Adolescent↗
PubMed1986

Fine-structural study of the pineal body of the monkey (Macaca fuscata) with special reference to synaptic formations.

Various types of synaptic formations on pinealocytes and pineal neurons were found in the pineal body of Macaca fuscata. Axo-somatic synapses of the Gray type-II category were detected on the pinealocyte cell body. Gap junctions and ribbon synapses were observed between adjacent pinealocytes. About 70 nerve-cell bodies were detected in one half of the whole pineal body bisected midsagittally. They were localized exclusively deep in the central part. When examined electron-microscopically, they were found to receive ribbon-synapse-like contacts from pinealocytic processes. They also received synaptic contacts of the Gray type-I category on their dendrites, and those of the Gray type-II category on their cell bodies from nerve terminals of unknown origin. All these synapse-forming axon terminals contained small clear vesicles. Thus, the pineal neurons of the monkey, at least in part, are suggested to be derived from the pineal ganglion cells in the lower vertebrates and not from the postganglionic parasympathetic neurons. The functional significance of these observations is discussed in relation to the innervation of the pineal body of the monkey.

Animals↗
PubMed1995

Expression of several muscle-specific genes during differentiation of cultured quail pineal body cells under artificial (high NaCl) conditions.

A change in cell differentiation of pineal body cells to cells with myogenic features can be induced when such cells are cultured with stepwise increases in the NaCl concentration up to a 125 mM NaCl excess. Further differentiation can be achieved by changing the culture medium to Cosmedium (serum-free) with the same high NaCl concentration. This system is a good candidate as an in vitro model for the commitment of pre-myoblastic cells to myogenic cells, and for studies on early phases of myogenic differentiation, since the myogenic fate is not selected under conventional isotonic culture conditions. Our first step was to analyze the expression schedule of an intermediate filament protein, desmin, as an early stage marker of muscle differentiation. Desmin expression was detected at a low level in mononucleated cells during early differentiation stages (two days in medium with a 50 mM excess of NaCl), and a higher order of expression was observed in later stages in 20-40% of cells corresponding to myotubes. Expression of qmf1 and qmf2 mRNA, quail counterparts of MyoD and myogenin, respectively, was detected in two different stages: in the pineal body of 9-day-old embryos and in myogenically differentiated pineal cells, by Northern blotting and RT-PCR analysis. When pineal cells were transferred to the culture system, qmf1 and qmf2 expression was not present in isotonic medium and no myogenic differentiation occurred under these conditions. However, they reappeared and increased during the final stages of myogenic differentiation in the high NaCl medium. Furthermore, by use of muscle-specific domain (MSD)-specific antibodies we found the expression of a muscle-specific neural cell adhesion molecule (NCAM) species at the late stages of differentiation. These results show that the gene expression and mRNA splicing patterns of the cells changed from pineal body-specific to muscle-specific. On the basis of these results, we conclude that this system is appropriate for studying the differentiation of non-muscle cells to muscle cells.

Animals↗
PubMed1984

[Gangliocytoma of the pineal body. A case report and general review].

A case of pineal gangliocytoma in a 51 year-old man is presented. He was admitted to the hospital on February 2, 1982, with complaints of headache, nuchal pain, blurred vision, nausea and vomiting of three years' duration. Neurological examination did not show any neurological deficits but bilateral choked disc. Preoperative CT scan disclosed a sharp by circumscribed high density lesion in the pineal region with moderate hydrocephalus. Preoperative 99m Tc-DTPA brain scan revealed a warm activity in the pineal region, and changes of its activity were only little in the course of time. Preoperative Amipaque ventriculogram showed dilation of the lateral ventricles and a shadow of the tumor bulging into the posterior half of the distended third ventricle. A diagnosis of tumor of the pineal region was made and removal of the tumor was performed by biparieto-occipital interhemispheric approach in "sea lion" position. The tumor was a dark reddish solid mass which replaced the pineal body and extended under the cerebellar tentorium. The patient made an uneventful recovery without any neurological deficits. By light microscopy, the neoplasm was composed mostly of mature and immature ganglion cells and small round cells with moderate cellularity and multiform cytologic features. Ganglion cells with large nuclei and prominent nucleoli had characteristic Nissl substance in various amounts. Oligodendrocytes and astrocytes appeared around the tumor but did not show neoplastic growth. GFAP stain did not show glial component in the tumor. According these findings, the tumor was diagnosed as gangliocytoma originated from the pineal body, and this was the first case in Japan.

Brain Neoplasms↗
PubMed1988

Comparison of calbindin D-28K immunoreactivity in superficial pineal bodies of mongolian gerbil and rat.

Immunocytochemical reaction for demonstration of calbindin D-28K has been performed in superficial pineal bodies of the Mongolian gerbil (Meriones unguiculatus) and the rat. Whereas in the Mongolian gerbil there were no clearly expressed calbindin immunoreactive cells, these were numerous in the rat pineal body. Here the calbindin-positive cells - probably pinealocytes - were disposed along capillaries. In view of the role of calbindin in binding and transporting calcium and regulating its intracellular levels, the absence of this protein in the gerbil pineal body has been interpreted as signifying the inability of pinealocytes to eliminate intracellular calcium with possible consequent formation of acervuli.

Animals↗
PubMed1988

Ultrastructure of the pineal body of the common vampire bat, Desmodus rotundus.

The type AB pineal body of the common vampire bat, Desmodus rotundus, was recessed and lobulated, was extensively vascularized and intimately related to great veins, and was unassociated with the epithalamic region. The habenular and the posterior commissures coursed anteriorly and were unassociated with the pineal. The saccular suprapineal recess of the third ventricle extended dorsally juxtaposed to the pineal body. These anatomical features are likely to make pinealectomies in the vampire more difficult to manage. The pineal parenchyma consisted of light pinealocytes surrounded by canaliculi of various sizes, often transmitting unmyelinated nerve fibers and glial processes. Desmosomes were common. The pinealocyte nuclei were large and highly infolded; characteristic cytoplasmic constituents included abundant dilated Golgi complexes associated with clear vesicles, numerous polyribosomes, few single cisternae of ribosome-studded rough endoplasmic reticulum, mitochondria, and occasional multivesicular bodies and lysosomes. Almost all pinealocytes exhibited centrioles and some, in addition, displayed basal bodies but rarely ciliary shafts. A conspicuous feature of the pinealocyte cytoplasm was the presence of branched bundles of intermediate filaments, especially in the perinuclear zone. Siderotic macrophages, lipofuscin-pigment-containing phagocytic cells, mast cells, myelin bodies, and both fenestrated and continuous capillaries were present. The perivascular compartment was densely packed with unmyelinated nerve bundles containing small to large fibers exhibiting axoaxonic densities. Other constituents of the perivascular compartment were club-shaped pinealocyte processes filled with clear vesicles, microtubules, an occasional mitochondrion, glial processes, and collagen fibers. "Synapselike" contacts were observed between the axons and pinealocyte processes. Abundant pinocytotic vesicles in the capillary endothelium indicated active pinocytosis. Myelinated nerve fibers were lacking. The pineal ultrastructure of Desmodus is in part unlike that reported for other mammals, including bats.

Animals↗
PubMed1976

Myelomatous metastasis to the pineal body.

The case is reported of a large metastasis to the pineal body in patient with plasma cell leukemia, a disorder akin to myelomatosis. There were no apparent clinical effects from the tumor in the pineal body. The brain was otherwise uninvolved. A discussion of the relevant literature is given.

Adult↗
PubMed1975

Identification of some substances secreted by the bovine pineal body and their antigonadotrophic activity in an in vitro system.

To aid elucidation of the chemical composition of the antigonadotrophic substances produced by the epiphysis cerebri, 100 bovine pineal bodies were incubated in Krebs-Ringer buffer and the incubate treated to give an ethyl acetate and an aqueous extract. Using thin layer chromatography on fluorescent silica gel plates, 5 indoles were identified and 6 unknown substances isolated from the pineal incubate and from both extracts. The presence of peptides was detected in the incubate and in the aqueous extract. The antigonadotrophic activity of the incubate and of the two extracts was examined using a continuous flow in vitro system with the production of luteinizing hormone (LH) from bovine adenohypophysial tissue as the final parameter. All three fractions were found to result in a somewhat similar production of LH. To distinguish between the antigonadotrophic activity attributable to the indole and the indole/protein components of the pineal secretion, 90 bovine pineal bodies were homogenized and the homogenate incubated in the continuous flow in vitro system in the presence or absence of trypsin and trypsin-inhibitor. Results were inconclusive regarding the role played by the indole and indole/protein fractions in the antigonadotrophic activity of the pineal body.

Acetates↗
PubMed1987

The major gangliosides of the bovine pineal body.

Acetone powders of fresh-frozen pineals were extracted with chloroform/methanol mixtures. By column chromatography on silicic acid, mild alkaline methanolysis, ion-exchange high performance liquid chromatography and a final thin layer chromatography on silicic acid, the major glycosphingolipids were purified from the extracts of a total of 300 bovine pineal bodies. Chromatographically purified fractions were characterized by gas chromatographic analysis. The most prominent glycosphingolipid appeared to be cerebroside. In addition, five different gangliosides were found in detectable levels. The two major gangliosides have the chromatographic and component characteristics of GD3 and GM3, with disialoganglioside predominating. Gangliosides indistinguishable from purchased standards of GM1 and GD1a were third and fourth, respectively, in amount. The fatty acid profiles of the two lactosyl gangliosides are similar and significantly different from those of the two gangliotetraose gangliosides. The fifth most prominent ganglioside, present at a level of 1.09% of total recovered ganglioside sialic acid, appears to be a novel trisialoganglioside, called GTx. This new molecule has a component ratio of gal:glc:sialic acid:amino sugar of approximately 1:2:3:1. Similarities between bovine pineal and rod outer segments are discussed.

Animals↗
PubMed2000

Spontaneous regression of a germinoma in the pineal body after placement of a ventriculoperitoneal shunt.

The authors report a case in which a germinoma in the pineal body displayed spontaneous regression after placement of a ventriculoperitoneal (VP) shunt. Spontaneous regression of malignant tumors is extremely rare, occurring in only one of 60,000 to 100,000 patients. Although in rare cases spontaneous regression is known to occur in patients with testicular seminomas, only one case of spontaneous regression of a primary pineal germinoma has so far been reported. In the present case a 17-year-old man presented with headache. A tumor in the pineal body and acute hydrocephalus were revealed by head computerized tomography (CT) and magnetic resonance (MR) imaging, and VP shunt placement was performed. Computerized tomography scanning of the head was performed four times during a 2-week period following the operation, and the patient was temporarily discharged to return to school. At the time of discharge, CT scanning demonstrated no change in the size of the tumor. Two months later, the patient was readmitted to the hospital to undergo surgery. At that time, head MR imaging revealed regression of the tumor. The pathological diagnosis of the lesion was germinoma. The patient underwent three courses of chemotherapy, during which carboplatin and etoposide were administered, in addition to a 24-Gy dose of radiotherapy. No manifestations of nerve impairment were noticed, and the patient was observed on an outpatient basis. The authors think that the factors involved in tumor regression included the effects of the VP shunt, the effects of radiation absorbed during head CT scanning, and the role of the patient's own immune response. However, no conclusion has been reached concerning the actual cause.

Adolescent↗
PubMed1995

Effects of pineal body and melatonin on lymphocyte proliferation and dinoprostone production in rat spleen.

AIM: To determine the effects of pineal body and melatonin (Mel) on lymphocyte proliferation and dinoprostone production in rat spleen. METHODS: Pinealectomy (PE), lymphocyte proliferation assay and dinoprostone radioimmunoassay were used. RESULTS: A circadian rhythm of splenic lymphocyte proliferation which peaked at 22:00 was obliterated by PE in rats. PE led to an impairment of lymphocyte proliferation and an increase of dinoprostone production, which were restored by ip Mel 10 micrograms.kg-1.d-1 at 16:00 for 7 d. Mel promoted lymphocyte proliferation and inhibited dinoprostone production in intact rats. A negative correlation between the change in lymphocyte proliferation and dinoprostone production was seen. CONCLUSION: The pineal body and its main hormone Mel play a regulatory role in circadian lymphocyte proliferation which is related to dinoprostone production in rat spleen.

Animals↗
PubMed1985

Monitoring of circadian fluctuations of N-acetylserotonin in the rat pineal body by differential pulse voltammetry.

Circadian fluctuations of the electrochemical signal appearing at +270 mV (peak 3) recorded from the pineal body of freely moving rats were first monitored for 24 hours using the in vivo voltammetry technique. The peak 3 height increased after injection of pargyline and S-adenosyl-L-homocysteine but decreased after injection of NSD-1015, while probenecid did not cause any change. Under a 12/12 hours light-dark cycle, the peak 3 height represented circadian fluctuations, similar to those of N-acetyltransferase activity, which were higher in the dark than in the light period. These data suggest that the compound responsible for peak 3 in the pineal body is essentially due to extracellular N-acetylserotonin.

Animals↗