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

The presence of vasoactive intestinal polypeptide (VIP) receptors coupled to an adenylate cyclase was demonstrated on membranes of neurons or glial cells grown in primary cultures originating from the cerebral cortex, striatum, and mesencephalon of mouse embryos. A biphasic pattern of activation was observed in all these cell types, involving distinct high- and low-apparent-affinity mechanisms. The absence of additive effects of VIP and 3,4-dihydroxyphenylethylamine (DA, dopamine), isoproterenol (ISO), and 5-hydroxytryptamine (5-HT, serotonin) suggests that the peptide receptors are colocated with each of the corresponding amine receptors on neuronal membranes of the three structures studied. The nonadditivity between the VIP- and ISO-induced responses on cortical and striatal glial membranes reveals as well a colocation of VIP and beta-adrenergic-sensitive adenylate cyclases on the same cells. A subpopulation of mesencephalic glia could possess only one of the two types of receptors, as a partial additivity of the VIP and ISO responses was seen. In addition, VIP modified the characteristics of the somatostatin inhibitory effect on adenylate cyclase activity of neuronal membranes from the cerebral cortex and striatum but not from those of the mesencephalon. On striatal and mesencephalic glial membranes the somatostatin inhibitory effect was observed only in the presence of VIP. However, as previously seen with ISO, the presence of VIP did not allow the appearance of a somatostatin inhibitory response on cortical glial membranes. This suggests that cortical glia are devoid of somatostatin receptors.
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PMID:Vasoactive intestinal polypeptide receptors linked to an adenylate cyclase, and their relationship with biogenic amine- and somatostatin-sensitive adenylate cyclases on central neuronal and glial cells in primary cultures. 285 67

Primary cultures of mouse embryonic neuronal or glial cells from the cerebral cortex, striatum, and mesencephalon were used to identify and determine the cellular localization of somatostatin receptors coupled to an adenylate cyclase. Somatostatin inhibited basal adenylate cyclase activity on neuronal but not on glial crude membranes in the three structures examined. The somatostatin-inhibitory effect on neuronal crude membranes was still observed in the presence of (-)-isoproterenol, 3,4-dihydroxyphenylethylamine (dopamine, DA), or 5-hydroxytryptamine (5-HT, serotonin) used at a concentration (10(-5) M) inducing maximal adenylate cyclase activation. In addition, in most cases biogenic amines modified the pattern of the somatostatin-inhibitory effect, triggering either an increase in the peptide apparent affinity for its receptors or an increase in the maximal reduction of adenylate cyclase activity or both. However, 5-HT did not modify the somatostatin-inhibitory response on striatal and cortical neuronal crude membranes. The changes in somatostatin-inhibitory responses were interpreted as a colocalization of the amine and the peptide receptors on subtypes of neuronal cell populations. Finally, somatostatin was shown to inhibit adenylate cyclase activity following its activation by (-)-isoproterenol on glial crude membranes of the striatum and the mesencephalon but not on those of the cerebral cortex.
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PMID:Modulation by monoamines of somatostatin-sensitive adenylate cyclase on neuronal and glial cells from the mouse brain in primary cultures. 285 57

Alzheimer's disease (AD) and senile dementia (SD) are often classified together, but there are genetic, biochemical, neuropathological and clinical arguments for separating them. The well-known Alzheimer lesions in the brains of patients with AD and SD are described, as is the loss of neurons in the locus coeruleus. White matter changes in brains from patients with dementia are discussed and related to AD and SD. Biochemical changes in brains of patients with AD and SD include reduced activity of acetylcholinesterase (AChE) and choline-acetyltransferase (CAT), indicating reduced activity in the acetylcholinergic system. There is also, however, reduced activity in the dopamine (DA), noradrenaline (NA) and 5-hydroxytryptamine (5-HT) system. The active amines are decreased while the end metabolites are decreased to a lesser extent or normal. The levels of the active amines are thought to reflect the number of neurons, while the levels of end metabolites reflect the rate of turnover in the system. 3-Methoxy-4-hydroxyphenylglycol (MHPG) is increased to levels above normal, which may indicate an increased rate of turnover in the NA system. Monoamine oxidase B (MAO-B), which is increased in advanced age, is further increased in patients with AD and SD. It is assumed that this enzyme is localized in extraneuronal tissue, and therefore the increase may reflect a gliosis. In brains from patients with AD and SD neuropeptides are also studied. Only somatostatin and substance P, however, seem to be reduced, indicating selective damage to the neuropeptides. The biochemical changes can be given pathogenetic importance.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Alzheimer's disease and senile dementia: biochemical characteristics and aspects of treatment. 286 36

The relative frequency and topographical distribution of proventricular endocrine cells were examined immunohistochemically in seven species of birds: common finch, pigeon, quail, chicken, duck, gull and kite. Gastrin releasing peptide (GRP), somatostatin-, avian pancreatic polypeptide (APP)-, glucagon-, 5-hydroxytryptamine (5-HT)- and neurotensin-immunoreactive cells were observed in this study. GRP- and somatostatin-immunoreactive cells were found in all species examined. All six kinds of immunoreactive cells were found with varying frequency in the pigeon, quail and gull, but not all immunoreactives were found in the other species examined. Species differences with regard to the relative frequency and topographical distribution of proventricular endocrine cells were observed.
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PMID:The relative frequency and topographical distribution of somatostatin-, GRP-, APP-, glucagon-, 5-HT-, and neurotensin-immunoreactive cells in the proventriculus of seven species of birds. 286 40

The ability of certain neuropeptides (glucagon, somatostatin, leu-enkephalin and neurotensin) to release known neurotransmitters (glycine, GABA, dopamine and 5-hydroxytryptamine) was tested in the chicken retina. Tritiated neurotransmitters were injected intravitreally in chicken eyes. After excision, the retina was stimulated in vitro with the neuropeptide in micromolar concentrations while monitoring the efflux of radioactivity from the retina. A rise of the efflux represents a stimulus dependent release. Neurotensin release [3H] glycine, [3H]dopamine and [3H]5-hydroxytryptamine. Leu-enkephalin released [3H]dopamine and somatostatin released [3H]5-hydroxytryptamine. Glucagon was without effect. [3H]GABA was not released by any of the neuropeptides.
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PMID:Neurotransmitter release by certain neuropeptides in the chicken retina. 286 56

Segi's cap, a large aggregation of endocrine cells on the top of intestinal villi, was studied in porcine fetuses and neonates by histological and immunohistochemical methods. The following observations were made: 1) Segi's caps were found in the proximal small intestine in all fetuses larger than 17 cm (beyond 10 weeks of gestation), in neonates before suckling and in 1-4 day-old piglets (suckling neonates); they were not found in a 1 week-old animal. 2) Segi's caps were seen more frequently in the distal duodenum and proximal jejunum than in the proximal and middle duodenum. 3) The Segi's cap consisted mainly of numerous argyrophil cells as demonstrated by Grimelius' method and a few argentaffin cells as identified by a modified Masson-Hamperl's method. 4) Immunohistochemically, ten kinds of immunoreactive cells were dispersed in the mucosal epithelium, outside of Segi's caps, in the proximal small intestine of fetuses: 5-hydroxytryptamine (5-HT)-, gastrin-, bovine pancreatic polypeptide (BPP)-, secretin-, somatostatin-, cholecystokinin-, gastric inhibitory polypeptide (GIP)-, motilin-, leucine-enkephalin- and neurotensin-immunoreactive cells. Except for neurotensin-immunoreactive cells, all of these cells were detected also in the caps. 5) Regional differences were noted in the distribution of cells in the caps; gastrin-, BPP- and secretin-immunoreactive cells were dominant in the caps in the proximal duodenum, while 5-HT-immunoreactive cells were most numerous in those in the proximal jejunum.
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PMID:Histological and immunohistochemical studies of the Segi's cap, a large aggregation of endocrine cells on the intestinal villi of porcine fetuses and neonates. 286 50

The aim of the present study was to evaluate the physiological role of intrapancreatic serotonergic nerves for endocrine pancreatic function. The specific uptake of [3H]5-hydroxytryptamine (5-HT) into pancreatic slices from the rat was completely abolished after an intrapancreatic injection of 5,7-dihydroxytryptamine (5,7-DHT). Since also high-affinity uptake of [3H]5-HT was absent it was concluded that intrapancreatic serotonergic nerves were destroyed. The effects of this selective denervation on glucose-stimulated insulin and somatostatin secretion were investigated with the aid of perfused rat pancreatic glands removed 3, 7 or 14 days after the injection of 5,7-DHT. Neither the basal release of these hormones nor their response to a glucose challenge was significantly altered by the ablation of the intrapancreatic serotonergic nerves. The microsphere technique was used to investigate the blood flow through the pancreatic islets in rats injected intrapencreatically with 5,7-DHT 4 days previously. No significant changes in either the whole pancreatic blood flow or the islet blood flow could be demonstrated. These result show that in normal physiological conditions the intrapancreatic serotonergic nerves do not affect the hormonal release from or the blood flow through the endocrine pancreas.
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PMID:Ablation of serotonergic nerves in the rat pancreas. Lack of effects on hormone secretion and intrinsic blood flow. 286 99

Noradrenaline (NA) and somatostatin (SOM) stimulate intestinal water and ion absorption and are found in mucosal nerve fibres and nerve terminals in submucous ganglia of the guinea-pig small intestine. As the main projection of submucous neurons is to the mucosa, NA and SOM might alter mucosal transport either by a direct effect on the epithelium or indirectly, by affecting submucous neurons. In this study these two possible sites of action of NA and SOM have been investigated in mucosa-submucosa preparations of guinea-pig ileum. In addition, the actions of NA and SOM on the secretory responses caused by stimulation of different populations of submucous neurons have been studied. The stimulants of secretion used were a nicotinic agonist, 1,1-dimethyl-4-phenylpiperazinium (DMPP, 10(-5) M), 5-hydroxytryptamine (5-HT, 10(-7) M) and electrical field stimulation (EFS), which activate cholinergic, noncholinergic and mixed populations of submucous secretomotor neurons, respectively. Segments of intestine were dissected free of external muscle and myenteric plexus and mounted in Ussing chambers. Short-circuit current (Isc) was measured as an indication of net active ion transport across the tissue. NA (greater than or equal to 10(-8) M) and SOM (greater than 10(-10) M) each caused a decrease in Isc, indicating a net increase in ion absorption. The NA response was abolished and the magnitude of the SOM response was reduced to 20% by tetrodotoxin (10(-7) M). DMPP, 5-HT and EFS each stimulated nerves that increased Isc and each of these responses was significantly diminished by NA and SOM.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of noradrenaline and somatostatin on basal and stimulated mucosal ion transport in the guinea-pig small intestine. 287 1

The pre- and post-hatching development and differentiation of the endocrine cells in quail gizzard were examined histologically and immunohistochemically. A total of 158 heads (from 5th d of incubation to adult) were used in this study. The formation of gizzard tubular glands began from 11th d of incubation. 8 kinds of endocrine cells, argyrophil cells, and gastrin releasing polypeptide (GRP)-, 5-hydroxytryptamine (5-HT)-, somatostatin-, glucagon-, avian pancreatic polypeptide (APP)-, neurotensin-, and gastrin-immunoreactive cells were detected in the gizzard. These endocrine cells began to appear from 10th d of incubation. Argyrophil cells and GRP-immunoreactive cells in the gizzard were increased with age. Other kinds of immunoreactive cells were found rarely and irregularly, and some of them were found transitory in the embryonic stage.
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PMID:Histological and immunohistochemical study on ontogeny of the endocrine cells in the quail gizzard. 288 69

Synaptic organization of the intermediolateral nucleus of the guinea pig thoracic spinal cord was examined with particular focus on monoamine- and peptide-containing nerve terminals. Axon varicosities having flat synaptic vesicles constituted 17% of all axons in the nucleus and formed exclusively symmetric synapses. Enkephalin-, substance P-, somatostatin-, 5-hydroxytryptamine-, and catecholamine-immunoreactive nerve terminals were densely distributed, while neurotensin, vasoactive intestinal polypeptide-, oxytocin-, and cholecystokinin-8-immunoreactive nerves were sparse in the nucleus. Coexistence of 5-hydroxytryptamine and enkephalin was demonstrated, and coexistence of somatostatin and enkephalin as well as somatostatin and 5-hydroxytryptamine in the same axons was also shown by serial semithin sections. Catecholamine axons labelled by 5-hydroxydopamine formed axodendritic and axosomatic synapses and made direct synaptic contacts on the preganglionic sympathetic neurons identified by retrograde transport of horseradish peroxidase. Direct synaptic contacts from enkephalin- and substance P-immunoreactive axons to preganglionic sympathetic neurons were also revealed. Enkephalin-, substance P-, and 5-hydroxytryptamine-immunoreactive axons formed axodendritic and axosomatic synapses. Catecholamine axon varicosities constituted 19% of all axon varicosities in the nucleus and 30% of them showed synaptic specializations in a sectional plane. Axon varicosities immunoreactive to enkephalin, 5-hydroxytryptamine, and substance P constituted approximately 35, 19, and 13% of all axon varicosities, respectively, while those with synaptic contacts made up 27, 30, and 26%, respectively, in a sectional plane. Enkephalin-, 5-hydroxytryptamine-, and noradrenaline-immunoreactive axons showed mainly symmetric synaptic contacts.
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PMID:Synaptic structure of the monoamine and peptide nerve terminals in the intermediolateral nucleus of the guinea pig thoracic spinal cord. 288 97


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