Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The comparative distribution of peptidergic neural systems in the brain of the euryhaline, viviparous teleost Poecilia latipinna (green molly) was examined by immunohistochemistry. Topographically distinct, but often overlapping, systems of neurons and fibres displaying immunoreactivity (ir) related to a range of neuropeptides were found in most brain areas. Neurosecretory and hypophysiotrophic hormones were localized to specific groups of neurons mostly within the preoptic and tuberal hypothalamus, giving fibre projections to the neurohypophysis, ventral telencephalon, thalamus, and brain stem. Separate vasotocin (AVT)-ir and isotocin (IST)-ir cells were located in the nucleus preopticus (nPO), but many AVT-ir nPO neurons also displayed growth hormone-releasing factor (GRF)-like-ir, and in some animals corticotrophin-releasing factor (CRF)-like-ir. The main group of CRF-ir neurons was located in the nucleus recessus anterioris, where coexistence with galanin (GAL) was observed in some cells. Enkephalin (ENK)-like-ir was occasionally present in a few IST-ir cells of the nPO and was also found in small neurons in the posterior tuberal hypothalamus and in a cluster of large cells in the dorsal midbrain tegmentum. Thyrotrophin-releasing hormone (TRH)-ir cells were found near the rostromedial tip of the nucleus recessus lateralis. Gonadotrophin-releasing hormone (GnRH)-ir cells were present in the nucleus olfactoretinalis, ventral telencephalon, preoptic area, and dorsal midbrain tegmentum. Molluscan cardioexcitatory peptide (FMRF-amide)-ir was colocalized with GnRH-ir in the ganglion cells and central projections of the nervus terminalis. Melanin-concentrating hormone (MCH)-ir neurons were restricted to the tuberal hypothalamus, mostly within the nucleus lateralis tuberis pars lateralis, and somatostatin (SRIF)-ir neurons were numerous throughout the periventricular areas of the diencephalon. A further group of SRIF-ir neurons extending from the ventral telencephalon into the dorsal telencephalon pars centralis also contained neuropeptide Y (NPY)-, peptide YY (PYY)-, and NPY flanking peptide (PSW)-like-ir. These immunoreactivities were, however, also observed in non-SRIF-ir cells and fibres, particularly in the mesencephalon. Calcitonin gene-related peptide (CGRP)-like-ir had a characteristic distribution in cells grouped in the isthmal region and fibre tracts running forward into the hypothalamus, most strikingly into the inferior lobes. Antisera to cholecystokinin (CCK) and neurokinin A (NK) or substance P (SP) stained very extensive, separate systems throughout the brain, with cells most consistently seen in the ventral telencephalon and periventricular hypothalamus. Broadly similar, but much more restricted, distributions of cells and fibres were seen with antisera to neurotensin (NT) and vasoactive intestinal peptide (VIP).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Comparative distribution of neuropeptide-immunoreactive systems in the brain of the green molly, Poecilia latipinna. 208 20

Light microscopic double immunocytochemical stainings, performed on sea bass hypothalamo-hypophysial sections, revealed the projection of different neuropeptide-immunoreactive neurons innervating the hormone-producing cell populations in the pituitary gland. In the rostral pars distalis (PD) the ACTH cells were found in close proximity to fibers immunoreactive for somatostatin (SRIF), growth hormone-releasing hormone (GRF), corticotropin-releasing hormone (CRF), vasotocin (VT), isotocin (IT), substance P (SP), neurotensin, and galanin (GAL), while the PRL cell zone seemed only innervated by nerve fibers immunopositive for GAL. In the proximal PD, fibers immunoreactive for SRIF, GRF, VT, IT, cholecystokinin, SP, neuropeptide Y, and GAL formed a close relationship with the growth hormone cells. The gonadotrophs were observed near nerve fibers immunostained for gonadotropin-releasing hormone, IT, and less obviously GRF and VT, while fibers positive for GRF, CRF, VT, IT, SP, and GAL penetrated between and formed a close association with the thyrotrophs. In the pars intermedia the MSH cells and the PAS-positive (PAS+) cells seemed both innervated by separate nerve fibers immunoreactive for GRF, CRF, melanin concentrating hormone, VT, IT, and SP. All these results suggest a functional role of the neuropeptides in the adenohypophysis of the sea bass, possibly in the synthesis and/or release of hypophysial hormones from the different cell types.
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PMID:Immunocytochemical demonstration of close relationships between neuropeptidergic nerve fibers and hormone-producing cell types in the adenohypophysis of the sea bass (Dicentrarchus labrax). 246 54

Previous light microscopic studies have revealed neuropeptide-immunoreactive neurosecretory fibers in the teleostean neurohypophysis, and ultrastructural work has reported direct innervation of endocrine cells by the terminals of fibers penetrating the adenohypophysis. This paper reviews our recent data from ultrastructural, immunohistochemical, receptor localization, and superfusion studies, which suggest a role for neuropeptides in the control of teleost pituitary secretion. We have used a combination of pre- and post-embedding electron microscopic immunolabeling methods to determine which neuropeptides are present in fibers innervating the pituitaries of three species: Poecilia latipinna, Dicentrarchus labrax, and Clarias gariepinus. Numerous axon profiles with immunoreactivity for the neurosecretory peptides vasotocin and isotocin formed large Herring bodies and terminal-like boutons in contact with corticotropic, growth hormone, thyrotropic, and pars intermedia cells. Numerous melanin-concentrating hormone-immunoreactive fibers and scarcer neurotensin and corticotropin-releasing factor-immunoreactive fibers showed similar distributions, terminating close to pars intermedia and corticotropic cells. Somatostatin, cholecystokinin, galanin, substance P, neuropeptide Y, growth hormone-releasing factor, thyrotropin-releasing hormone, and gonadotropin-releasing hormone-immunoreactivities were found in small calibre fibers penetrating among growth hormone, thyrotropic, and gonadotropic cells. These morphological findings have been supplemented by autoradiographic studies, which showed the distribution of binding sites for vasotocin, isotocin, galanin, and neuropeptide Y ligands over specific groups of pituitary cells, and superfusion studies that showed growth hormone release was stimulated by growth hormone-releasing factor and thyrotropin-releasing hormone, but inhibited by somatostatin. The implications of these results for neuropeptidergic control of teleostean pituitary secretions are discussed.
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PMID:Innervation and control of the adenohypophysis by hypothalamic peptidergic neurons in teleost fishes: EM immunohistochemical evidence. 991 61

The novel neuropeptide cocaine-amphetamine-regulated transcript (CART) is expressed in several hypothalamic regions and has recently been shown to be involved in the central control of food intake. To characterize the hypothalamic CART neurons and understand the physiological functions they might serve, we undertook an in situ hybridization and immunohistochemical study to examine distribution and neurochemical phenotype of these neurons. In situ hybridization studies showed abundant CART mRNA in the periventricular nucleus (PeV), the paraventricular nucleus of the hypothalamus (PVN), the supraoptic nucleus (SON), the arcuate nucleus (Arc), the zona incerta, and the lateral hypothalamic area. The distribution of CART-immunoreactive neurons as revealed by a monoclonal antibody raised against CART(41-89) displayed complete overlap with CART mRNA. Double immunohistochemistry showed co-existence of CART immunoreactivity (CART-IR) and somatostatin in some neurons of the PeV. In the magnocellular division of the PVN as well as the SON, CART-IR was demonstrated in both oxytocinergic and vasopressinergic perikarya. In the medial parvicellular region of the PVN a few CART-IR neurons co-localized galanin, but none was found to co-localize corticotropin-releasing hormone. In the Arc, almost all pro-opiomelanocortinergic neurons were shown to contain CART, whereas no co-localization of CART with NPY was found. In the lateral hypothalamic area nearly all CART neurons were found to contain melanin-concentrating hormone. The present data support a role for CART in neuroendocrine regulation. Most interestingly, CART is co-stored with neurotransmitters having both positive (melanin-concentrating hormone) as well as a negative (pro-opiomelanocortin) effect on food intake and energy balance.
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PMID:Neurochemical characterization of hypothalamic cocaine- amphetamine-regulated transcript neurons. 1023 51

Orphan G-protein-coupled receptors (GPCRs) are cloned proteins with structural characteristics common to the GPCRs but that bind unidentified ligands. Orphan GPCRs have been used as targets to identify novel transmitter molecules. Here we describe the isolation from brain extracts and the characterization of the natural ligand of a particular orphan GPCR (SLC-1) that is sequentially homologous to the somatostatin receptors. We show that the natural ligand of this receptor is the neuropeptide melanin-concentrating hormone (MCH). MCH is a cyclic peptide that regulates a variety of functions in the mammalian brain, in particular feeding behaviour. We demonstrate that nanomolar concentrations of MCH strongly activate SLC-1-related pathways through G(alpha)i and/or G(alpha)q proteins. We have analysed the tissue localization of the MCH receptor and find that it is expressed in several brain regions, in particular those involved in olfactory learning and reinforcement mechanisms, indicating that therapies targeting the MCH receptor should act on the neuronal regulation of food consumption.
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PMID:Molecular characterization of the melanin-concentrating-hormone receptor. 1042 68

Orexin immunoreactive fibres are abundant in the hypothalamus suggesting a neuroendocrine regulatory role. Intracerebroventricular (ICV) administration of orexin A suppressed plasma prolactin in male rats by 71% at 20 min post-injection and 83% at 90 min post-injection (P < 0.005 vs saline at both time points). To investigate whether this effect was through the tuberoinfundibular dopaminergic (TIDA) system, a supra-maximal dose of domperidone, a dopamine receptor antagonist, was injected intraperitoneally (i.p.) prior to ICV injection of orexin A. ICV orexin A significantly suppressed domperidone (9 mg/kg)-stimulated plasma prolactin levels, by up to 40% (i.p. domperidone + ICV orexin A 3 nmol 34.5 +/- 7.4 ng/ml and i.p. domperidone + ICV orexin A 20 nmol 43.5 +/- 4.3 ng/ml, both P < 0.005 vs i.p. domperidone + ICV saline 57.9 +/- 2.7 ng/ml). Orexin A, 100 nM, significantly stimulated release of neurotensin, vasoactive intestinal polypeptide, somatostatin, corticotropin releasing factor and luteinizing hormone releasing hormone, but had no effect on release of dopamine, thyrotropin releasing hormone (TRH), vasopressin or melanin-concentrating hormone from hypothalamic explants in vitro. Orexin A did not alter basal or TRH stimulated prolactin release in dispersed pituitary cells harvested from male rats. The data suggest that ICV administration of orexin A suppresses plasma prolactin in part through a pathway independent of the dopaminergic system.
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PMID:Central administration of orexin A suppresses basal and domperidone stimulated plasma prolactin. 1110 80

A DNA fragment encoding an amino acid sequence possessing common features to the G protein-coupled receptor (GPCR) superfamily was found in the human genomic sequence, and from this information, the full-length cDNA of a novel GPCR, designated SLT, was cloned from the human hippocampus cDNA library. SLT showed the highest homology to the melanin-concentrating hormone (MCH) receptor, SLC-1 (31.5% identity), and to a lesser extent, to the somatostatin (SST) receptor subtypes. MCH exhibited agonistic behavior when applied to the SLT-expressing CHO cells at subnanomolar doses whereas more than 200 known peptides, including SST and cortistatin, did not. These results indicated that MCH is the cognate ligand of the SLT receptor and that this newly cloned GPCR is the second subtype of the MCH receptor. Quantitative polymerase chain reaction analysis of the SLT gene expression in human tissues showed that the SLT receptor is expressed mainly in brain areas including the cerebral cortex, amygdala, hippocampus, and corpus callosum, as well as in a limited number of peripheral tissues. The distribution of the SLT nearly overlapped that of SLC-1, suggesting that some of the neural functions of MCH may be mediated by both of these receptor subtypes.
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PMID:Cloning of a novel G protein-coupled receptor, SLT, a subtype of the melanin-concentrating hormone receptor. 1135 73

The neuropeptides orexin-A and orexin-B are produced in neurons of the lateral hypothalamic area and have been implicated to be involved in the regulation of food/water intake and sleep-wake control. The orexins act at two different G-protein-coupled orexin receptors (OX-R1 and OX-R2) that are derived from separate genes and expressed differentially throughout the central nervous system. In the present study, we have used a polyclonal antipeptide antiserum to analyse in detail the distribution of OX-R1-immunoreactive neurons in the rat hypothalamus. In order to identify the chemical mediators of orexin action in the hypothalamus, the OX-R1-containing neurons were characterized with regard to the content of peptides shown previously to affect ingestive and drinking behaviour. Neurons containing OX-R1 immunoreactivity were widely distributed in the hypothalamus with cell bodies located in the suprachiasmatic, periventricular, paraventricular (both magno- and parvocellular division), supraoptic, arcuate, ventromedial, dorsomedial and tuberomammillary nuclei and the lateral hypothalamic area. In magnocellular neurons of the paraventricular and supraoptic nuclei, OX-R1 immunoreactivity was seen in both vasopressin- and oxytocin-containing neurons. OX-R1 immunoreactivity was demonstrated in vasopressin and vasoactive intestinal polypeptide (VIP) neurons of the suprachiasmatic nucleus, in somatostatin neurons of the periventricular nucleus and in corticotropin-releasing hormone (CRH) neurons of the parvocellular paraventricular nucleus. In the arcuate nucleus, OX-R1 immunoreactivity was present in neuropeptide Y (NPY) and agouti-related peptide (AGRP) neurons of the ventromedial part as well as in proopiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript (CART) neurons of the ventrolateral division. In the lateral hypothalamic area, OX-R1 immunoreactivity was demonstrated in melanin-concentrating hormone (MCH)- and orexin-containing neurons. In the hypothalamic tuberomammillary nucleus, OX-R1-immunoreactivity was shown in many histamine-containing neurons. The results support the idea that orexins have important actions on hypothalamic neurons that control food intake and fluid balance, but also that orexins may regulate other neuroendocrine systems.
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PMID:Orexin receptor-1 (OX-R1) immunoreactivity in chemically identified neurons of the hypothalamus: focus on orexin targets involved in control of food and water intake. 1184 98

Ghrelin, the endogenous ligand of the GH secretagogue receptor, acts at central level to elicit GH release and regulate food intake. To elucidate the neural circuit that exerts its effects, we measured the expression of hypothalamic neuropeptides involved in weight regulation and GH secretion after ghrelin administration. Adult male rats, fed or fasted for 72 h, were treated centrally (intracerebroventicularly) with a single dose of ghrelin (5 micro g). After 2, 4, and 6 or 8 h, agouti-related peptide, melanin-concentrating hormone, neuropeptide Y, prepro-orexin, GHRH, and somatostatin mRNA levels were measured by in situ hybridization. We found that ghrelin increased agouti-related peptide and neuropeptide Y expression in the arcuate nucleus of the hypothalamus of fed and fasted rats. In contrast, no change was demonstrated in the mRNA levels of the other neuropeptides studied at any time evaluated. Finally, we examined the effect of ghrelin on GHRH and somatostatin mRNA levels in GH-deficient (dwarf) rats. Our results show that ghrelin increases somatostatin mRNA levels in the hypothalamus of these rats. This study furthers our understanding of the molecular basis and mechanisms involved in the effect of ghrelin on food intake and GH secretion.
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PMID:Agouti-related peptide, neuropeptide Y, and somatostatin-producing neurons are targets for ghrelin actions in the rat hypothalamus. 1253 15

Lanreotide was labelled with 188Re obtained from 188W/188Re generator, using stannous ion as reducing agent, ascorbic acid as stabilizers and hydroxy ethylidene bisphosphonate (HEDP) as intermediary ligand at different molar ratios, pH and incubation times. Best yields (>95%) were obtained using molar ratios SnF2/lanreotide, ascorbic/lanreotide and HEDP/lanreotide of 40, 12 and 260, respectively, pH 1-2 with an incubation at 100 degrees C for 30 min. Quality control evaluation and stability of the radiolabel compound was done by the following selected methods: chromatography in Whatman 3 MM with MEK and NaCl 0.15 M as solvents, ITLC-SG with ethanol-HCl 0.01N (90:10); reverse phase extraction cartridge (Sep-pak C18, Waters Associated) and RP-HPLC with radiometric and UV detection (220 nm) using MCH-5 n-capp column with linear gradient from 90% H2O (TFA 0.1%): 10% ACN (TFA 0.1%) up to 10% H2O (TFA 0.1%):90% ACN (TFA 0.1%) in 30 min, at flow 1 ml/min. Biodistribution in normal mice showed that 188Re-lanreotide is excreted mainly through the hepatobiliary system: more than 70% I.D. is present in gallbladder and intestines at 2 hr post injection. The stability of the 188Re-peptide bond by cysteine challenge test at 37 degrees C, during 2 and 24 hr of incubation time, reveals that approximately 300 and 100 molar ratio cys/peptide is required to displace 50% of the 188Re from the complex. In vitro stability of 188Re-lanreotide at room temperature (Rt) was demonstrated during 24 hr Future works must be done in order to investigate its binding capacity to somatostatin receptors.
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PMID:Labeling and quality control of 188Re-lanreotide. 1261 68


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