UNIPROT:P61278 - FACTA Search

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Query: UNIPROT:P61278 (somatostatin)
22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The survival and cellular and connective organization of intracephalic transplants of developing, freeze-stored rat hippocampal tissue were examined. Blocks of tissue containing the hippocampus and fascia dentata were obtained from late embryonic (E16-E22) and early postnatal rats (P0-P4) and immersed in a tissue culture medium with 10% of the cryoprotective agent DMSO, frozen at a cooling rate of approximately 1 degree C/minute, and stored for 1-226 days in liquid nitrogen. After quick thawing and washing out of the DMSO the tissue blocks were transplanted to the brain of adult rats. From 2 weeks to 3 months later the recipient brains were processed histologically. The cellular and connective organization of the transplants and their interaction with the host brains were analyzed after thionin cell staining, Timm's staining for hippocampal and dentate afferents, immunohistochemical staining for enkephalin-, CCK-, and somatostatin-reactive neurons and afferents, AChE staining for cholinergic afferents, and silver stains for fiber architectonics and tracing of connections by anterograde axonal degeneration. Freeze-storage narrowed the range of donor ages with good transplant survival. The best surviving hippocampal and dentate transplants thus came from 17-21-day-old embryos. There was no correlation between the length of storage and survival. Structurally the transplants of stored tissue were more frequently fragmented than the transplants of fresh tissue when located outside the brain parenchyma in the brain ventricles. This was in accordance with the results of a previous study of grafts of freeze-stored and fresh hippocampal tissue placed in the anterior eye chamber. Despite the decrease in survival and the tendency for fragmentation many well-structured and organotypically organized hippocampal and dentate transplants were recovered corresponding to the donor ages E19-E21. In addition to the main cell types (granule cells and pyramidal cells) the freeze-stored transplants also contained peptidergic nerve cells reacting for CCK, somatostatin, and enkephalin. The organization of the intrinsic nerve connections and the exchange of connections with the host brain were similar for transplants of stored and fresh tissue. Besides the consistent innervation of the hippocampal and dentate transplants by host cholinergic afferents monitored by AChE staining, several appropriately located dentate transplants thus sent mossy fibers to the host CA3. Others received host perforant path projections. A CA3-associated transplant projection to the denervated perforant path zones in the host fascia dentata was also observed.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Intracephalic transplants of freeze-stored rat hippocampal tissue. 378 12

A system for studying growth and development of transplanted subpopulations of postmitotic cerebral cortical neurons is described. The cytotoxic drug methylazoxymethanol (MAM) was given to pregnant rats on the fourteenth day of gestation to destroy precursor cells of layers II-IV of the fetal cerebral cortex. Layer V and VI precursor cells which had completed their final division before MAM treatment and were unaffected by it, were labeled by a prior injection of [3H]thymidine. This strategy provides a donor cerebral cortex containing mainly neurons destined to form layers V and VI of the adult cerebral cortex; these cells are postmitotic. Pieces of donor cerebral cortex were transplanted to the cerebral hemispheres of normal newborn hosts at one day, two days, or 6 days after MAM treatment; survival was assessed 1-12 weeks after transplantation by autoradiography of histological sections. Radiolabeled graft cells survived in 89% of recipients and many of these grew axons into the host, as indicated by retrograde labeling with horseradish peroxidase. Significant numbers of graft cells could also be stained immunocytochemically for glutamic acid decarboxylase or for the peptides, somatostatin, vasoactive intestinal polypeptide or cholecystokinin. A second group of experiments examined the routes of early axon outgrowth from normal and postmitotic fetal grafts. When the donor cortex had been incubated in a mixture of [3H]proline and [3H]leucine for 20 min prior to transplantation, the earliest axons growing out of the graft into normal newborn hosts could be assessed by autoradiography of axoplasmic transport after survivals in the host of 7 days. Normal and postmitotic grafts taken at E15 or E20 were capable of outgrowth, though the axons of E20 postmitotic cells did not grow far. The location of the transplant was the major determinant of where graft cells' axons grew and growth was mainly into existing axonal pathways of the host. In a third group of experiments, long term axonal projections from normal and postmitotic fetal transplants to 4 regions of the host brain--thalamus, contralateral cortex, striatum, and hippocampus--were examined with retrograde tracers 2-4 months after transplantation. Projections from grafts to the 4 host sites were highly dependent on the presence of nearby host axons connecting with those sites. Neurons in all types of graft projected to one or other of the 4 sites, but generally in small numbers. Higher proportions of cells in grafts from E15 MAM-treated donors projected to the host thalamus.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Transplantation of fetal postmitotic neurons to rat cortex: survival, early pathway choices and long-term projections of outgrowing axons. 404 17

Combined retrograde axonal tracing with the fluorescent dye Fast Blue and fluoride-resistant acid phosphatase (FRAP) histochemistry revealed that the FRAP-containing sensory neurons project to both somatic and autonomic peripheral nerves. Furthermore, the combination of indirect immunohistochemistry after colchicine treatment and FRAP histochemistry showed that a population of FRAP-containing sensory neurons are also substance P, cholecystokinin or somatostatin positive.
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PMID:Peripheral projections and neuropeptide coexistence in a subpopulation of fluoride-resistant acid phosphatase reactive spinal primary sensory neurons. 609 69

Following the discovery of the growth hormone release-inhibiting factor somatostatin from extracts of ovine hypothalamus, an N-terminally extended somatostatin of 28 amino acids has been identified in mammalian tissue. The original peptide, somatostatin-14 (SS14), corresponds to the C-terminus of somatostatin-28 (SS28). Both SS28 and SS14 have biological activity, occur in several rat brain regions, are present in cell bodies and nerve terminals and can be released in vitro upon depolarization in a calcium-dependent manner. Further, high-affinity binding sites were described for SS14, which also bind SS28 (refs 20-23). Recently, a dodecapeptide which corresponds to the N-terminus of somatostatin-28, somatostatin-28(1-12), has been characterized in rat hypothalamus. Radioimmunological and immunohistochemical studies have indicated the presence of SS28(1-12)-like immunoreactivity in several cortical and subcortical regions of the rat brain. This peptide was found to be unevenly distributed with the highest concentration in the hypothalamus, and preferentially localized to dendritic and axonal processes and terminals. These observations suggest that SS28(1-12) may be a neurotransmitter. In this study, we describe a calcium-dependent release of a SS28(1-12)-like peptide from hypothalamic slices in vitro. This finding supports a neurotransmitter function for this peptide.
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PMID:Release of somatostatin-28(1-12) from rat hypothalamus in vitro. 613 Apr 76

A system of somatostatin-immunoreactive neurons was demonstrated in the brains of the eel, Anguilla anguilla, the European minnow, Phoxinus phoxinus, and the rainbow trout, Salmo gairdneri, by means of the light-microscopic indirect immunoperoxidase technique. In the anterior periventricular nucleus, somatostatin-immunoreactive cerebrospinal fluid (CSF)-contacting neurons display intensely stained intraventricular dendritic protrusions, perikarya, and axonal processes. The latter taper into a somatostatin-immunoreactive fiber plexus extending to the infundibulum, the proximal neurohypophysis, and the lateral and mammillary recesses. In addition, somatostatin-immunoreactive neurons were demonstrated in the magnocellular preoptic, entopeduncular and dorsolateral thalamic nuclei, further in the pretectal area and the ventrolateral tegmentum. Somatostatin-immunoreactive fiber bundles project via the stria medullaris toward the habenular nucleus; they also course in the dorsomedial-ventrolateral direction at the level of the pretectal-tegmental area, and within the ventral and dorsal tegmentum. The presence of somatostatin in a variety of different neurons of the teleost brain is discussed in connection with their tentative inhibitory function. The CSF-contacting neurons of the anterior periventricular nucleus are supposed to function as sensors that pass information from the CSF to the somatostatin system of the hypothalamus and/or other components of the neuroendocrine apparatus.
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PMID:CSF-contacting and other somatostatin-immunoreactive neurons in the brains of Anguilla anguilla, Phoxinus phoxinus, and Salmo gairdneri (Teleostei). 613 83

The development of immunoreactive (ir) somatostatin-containing nerve terminals in the rat median eminence (ME) has been examined electron-microscopically. Nerve fibers containing ir particles scattered throughout the axoplasm are first seen in the external layer of the ME on day 18.5 of gestation, and, on day 21.5 appear to terminate on the basement membrane of the perivascular space of the portal vessels. After birth, the fiber terminals contain several membrane-limited granules, which are labeled with ir PAP particles. Ultrathin, Epon-embedded sections of ME, treated by the protein A gold-labeling method for somatostatin, demonstrate positively labeled granules in the nerve fibers in the postnatal ME, but in the prenatal tissue, no specific gold-labeling is found. These findings show that, in the external layer of the ME, somatostatin storing occurs in the granules in the axonal terminals after birth.
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PMID:Ontogenetic appearance of somatostatin-containing nerve terminals in the median eminence of rats. 614 19

The regulation of gastrin and somatostatin secretion by intraluminal chemicals was examined in an isolated vascularly perfused rat stomach, a preparation that maintains the integrity of intramural neural pathways and the polarity of stimulation. Intraluminal perfusion with alkaline solutions (0.1 M NaHCO3) increased gastrin secretion, whereas perfusion with acid solutions (pH 3.5-3.0) inhibited gastrin secretion. Perfusion with 0.5% or 5% peptone solutions stimulated gastrin secretion and inhibited somatostatin secretion. Both these responses were abolished by addition of the axonal blocker, tetrodotoxin (10(-6) M), to the vascular perfusate, from which it was concluded that gastrin and somatostatin responses induced by peptone were mediated by intramural neurons. These neurons were both cholinergic and noncholinergic, because addition of an optimal dose of atropine (10(-7) M) to the vascular perfusate inhibited only partially the gastrin response and converted the somatostatin response from decrease below basal levels--a typical cholinergic effect--to significant increase above basal levels. As shown previously, atropine had an identical effect on gastrin and somatostatin responses to transmural electrical stimulation of the antral region. The results are in accord with a model for the regulation of gastrin secretion by intramural cholinergic and noncholinergic neurons. A direct effect of intraluminal chemicals on gastrin and somatostatin cells was not detected in this study, but is not precluded.
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PMID:Stimulation of gastrin secretion in vitro by intraluminal chemicals: regulation by intramural cholinergic and noncholinergic neurons. 614 51

This study examined the cellular and connective organization of hippocampal tissue taken from 6-8-day-old rats and cultured by the roller tube technique for 3-6 weeks. In the cultures containing the fascia dentata and the hippocampus proper (CA1, CA3, CA4) the main cell and neuropil layers were organotypically organized when observed in ordinary cell stains. The normal distribution of smaller cell populations of AChE-positive neurons and somatostatin-reactive neurons was demonstrated by histochemical and immunohistochemical methods. Both cell types were mainly confined to str. oriens of CA3 and CA1 and the dentate hilus (CA4). Individual dentate granule cells and hippocampal pyramidal cells were injected with lucifer yellow and HRP, revealing great stability of the dendritic patterns of these cells in the culture condition. The same was found for the axonal branching and termination of HRP-filled mossy fibers arising from an HRP-injected granule cell. The preservation of organotypic afferent patterns in the cultures was also shown by Timm staining of the terminal distribution of the mossy fiber system. Mossy fiber terminals, with characteristic ultrastructural features verified in the electron microscope, were thus found in the hilus (CA4) and along the CA3 pyramidal cell layer onto the CA3-CA1 transition. Depending on the amount of dentate tissue relative to CA3 the terminals could stop before reaching CA1 (small fascia dentata) or take up additional intra and infrapyramidal locations along CA3 (small CA3). In cultures with a gap in the CA3 pyramidal cell layer some mossy fiber terminals were found in contact with the CA3 pyramidal cells beyond the gap. In all cultures there was an aberrant projection of supragranular mossy fibers. This projection is analogous to the one known from lesion and transplant studies to form in the absence of the entorhinal perforant path input to the dentate molecular layer. Also, in accordance with these studies the Timm staining pattern of the outer parts of the dentate molecular layer and the entire molecular layer of the hippocampus was altered corresponding to the spread of afferents normally confined to the inner zone of the dentate and str. radiatum of CA3 and CA1. Possibly as a consequence of the lack of normal targets for projections from CA1, this subfield contained an unusually dense Timm staining suggestive of autoinnervation.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Cellular and connective organization of slice cultures of the rat hippocampus and fascia dentata. 614 64

The distribution of vasopressin-, vasoactive intestinal polypeptide-, somatostatin-, avian pancreatic polypeptide-, 5-hydroxytryptamine- and glutamic acid decarboxylase-like immunoreactivity was analyzed in the suprachiasmatic nuclei of male and female golden hamsters. Vasopressin. Vasopressin-like immunoreactivity is localized within neurons, dendrites and axons throughout the rostrocaudal extent of the suprachiasmatic nuclei. Immunoreactive perikarya are restricted to the dorsomedial aspect of each nucleus and occur in highest numbers within the intermediate two-thirds of the rostrocaudal axis. Axons containing vasopressin-like immunoreactivity form a dense plexus in the dorsomedial suprachiasmatic nuclei and in a vertical column at the lateral aspect of each nucleus. Somatostatin. Somatostatin-like immunoreactivity is also contained in neurons in the dorsomedial aspect of the suprachiasmatic nuclei and in thin varicose axons distributed throughout the suprachiasmatic nuclei in a pattern similar to that of vasopressin-immunoreactive axons. Vasoactive intestinal polypeptide. Vasoactive intestinal polypeptide-immunoreactive neurons are concentrated in the ventrolateral portion of each nucleus and occur almost exclusively within the intermediate two-thirds of the rostrocaudal axis. An extremely dense plexus of varicose axons exhibiting vasoactive intestinal polypeptide-like immunoreactivity extends throughout the suprachiasmatic nuclei and passes out of the dorsal aspect of each nucleus into the periventricular and anterior hypothalamic areas. Avian pancreatic polypeptide. Avian pancreatic polypeptide-like immunoreactivity is restricted to axons which arborize within the ventrolateral aspect of each nucleus. These fibers extend throughout the rostrocaudal extent of each nucleus and partially overlap the terminal field of retinal afferents. Glutamic acid decarboxylase. A very dense plexus of axonal varicosities exhibiting glutamic acid decarboxylase-like immunoreactivity fills both the dorsomedial and ventrolateral portions of the suprachiasmatic nuclei throughout the rostrocaudal extent of each nucleus. Lightly stained immunoreactive perikarya also occur throughout the suprachiasmatic nuclei. 5-Hydroxytryptamine. 5-Hydroxytryptamine-like immunoreactivity is restricted to axons which form a plexus in the ventromedial portion of each nucleus that is most dense in the intermediate two-thirds of the rostrocaudal axis.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The suprachiasmatic nucleus of the golden hamster: immunohistochemical analysis of cell and fiber distribution. 615 Nov 47

Accumulations of the neuropeptides substance P (SP), somatostatin (ST), and vasoactive intestinal polypeptide (VIP) proximal to a crush in the cervical vagus nerve of the rat have been measured using sensitive radioimmunoassays. Each of the peptides was rapidly transport towards the peripheral terminals of vagal afferent fibres, with average rates of flow ranging from 0.8 to 2.7 mm h-1. In the rabbit vagus nerve, SP was transported with an average rate of 4 mm h-1, which is more than double the rate for this peptide in the rat. Double crush experiments in rabbit vagus nerves indicated that the rapidly transported proportion of the total content of SP in the nerve free was about 34%. From this, the rate of transport of SP in the rapidly transported pool in the rabbit vagus nerve can be calculated to be 12 mm h-1 (280 mm day-1). Since such double crush experiments were not possible in the rat, it is not clear whether the different average rates of transport of SP in the rat and the rabbit reflect real differences in the rate of rapid transport in the two species. In common with rapid axonal transport of other neurotransmitters, the transport of SP and ST in the rat vagus nerve was blocked by colchicine, a drug that disrupts microtubules.
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PMID:Axonal transport of neuropeptides in the cervical vagus nerve of the rat. 616 Dec 10

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