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)

We have developed a model to allow study of the release of somatostatinlike immunoreactivity (SLI) from gastric mucosal cells. Collagenase-dispersed canine fundic mucosal cells were separated by counterflow elutriation. SLI-containing cells were identified in the fractions with small cells (9-11 microns), and these fractions were plated onto collagen. After 2 days in culture, SLI content of the cells was maintained; SLI-positive cells, detected by peroxidase-antiperoxidase immunohistochemistry, comprised 70 +/- 6% (mean +/- SE, n = 6) of these cultured cells. Release of SLI from these cultures into the medium was determined by radioimmunoassay. Epinephrine, dibutyryl cAMP, and gastrin each stimulated SLI release in a time-dependent manner, with a steady rate of secretion maintained for 120 min of incubation. Both epinephrine and dibutyryl cAMP markedly potentiated the release of SLI stimulated by gastrin but were not themselves mutually potentiating. Upon Sephadex G-50 column chromatography of incubation medium and extracts of cultured cells, SLI eluted primarily in a single peak that cochromatographed with synthetic somatostatin tetradecapeptide. Our data suggest that gastrin and adrenergic stimuli act directly on canine fundic somatostatin cells and that potentiating interactions between secretagogues may be important modulating elements in somatostatin cell secretory function.
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PMID:Release of somatostatinlike immunoreactivity from canine fundic mucosal cells in primary culture. 614 97

A peptide fraction containing two 28-residue somatostatins, both products of the anglerfish somatostatin II gene, has been isolated, characterized, and subjected to amino acid sequence analysis. The structural data indicate that one of the two forms of the 28-residue peptide contains 5-hydroxylysine. Hydroxylysine was identified in an acid hydrolysate of somatostatin-28 by gas chromatography/mass spectrometry. Fast-atom bombardment mass spectrometry indicated that the two forms of somatostatin-28 have molecular weights of 3220 and 3204, representing the hydroxylated and nonhydroxylated peptides, respectively. The location of the hydroxylated lysine was deduced by analysis of proteolytic fragments to be position 23. This represents the first observation of a hydroxylated peptide hormone and one of the few reported occurrences of hydroxylysine in non-collagen proteins.
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PMID:Anglerfish preprosomatostatin II is processed to somatostatin-28 and contains hydroxylysine at residue 23. 615 Sep 31

Specimens of hypertrophic scar tissue (n = 9), non-hypertrophic, flat scar tissue (n = 5) and control skin (n = 3) were obtained from eight adult females (aged 22-56) and three adult males (aged 22-59). The specimens were studied histologically and immunohistochemically for vasoactive intestinal polypeptide, neuropeptide Y, calcitonin gene-related peptide, substance P, somatostatin, [Met]enkephalin, [Leu]enkephalin, and the enzyme dopamine beta-hydroxylase. The non-hypertrophic scar tissues were not dissimilar to the control tissue, but contained connective tissue in bundles with a greater number of collagen fibres. In the hypertrophic scar tissue of some patients, the dermis contained adipose tissue displaced upwards from the hypodermis. The connective tissue contained densely packed collagen fibres and fibroblasts; this region was devoid of hair follicles, sweat glands and blood vessels, although they were observed in the region of loosely packed connective tissue. The normal skin contained all the neuropeptides studied, except somatostatin-, and dopamine beta-hydroxylase-immunoreactive nerves, which were seen as single fibres or in nerve bundles, and were associated with blood vessels in the dermis. Neuropeptide Y-immunoreactive nerves were found in the arrector pili muscle, and neuropeptide Y-, vasoactive intestinal polypeptide-, calcitonin gene-related peptide-, [Met]enkephalin- and dopamine beta-hydroxylase-containing nerves were found within sweat glands. In patients with flat, non-hypertrophic scar tissue, neuropeptides and dopamine beta-hydroxylase-containing nerves were absent. In patients with hypertrophic scars, the density of neuropeptide Y-, vasoactive intestinal polypeptide-, substance P-, calcitonin gene-related peptide- and dopamine beta-hydroxylase-immunoreactive nerves was greater in the dermis when compared with controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Neuropeptide-containing nerves in painful hypertrophic human scar tissue. 751 32

A unique group of neurons in the submucous plexus of the gastrointestinal tract in guinea pigs was studied using (1) Nissl staining and an enzyme histochemical technique for acetylcholinesterase (AChE), (2) immunohistochemical methods for the localisation of neuron specific enolase (NSE) and neuropeptides, including vasoactive intestinal peptide (VIP), substance P (SP), somatostatin (SOM), calcitonin gene-related peptide (CGRP), leu-enkephalin (leu-ENK), neuropeptide (NPY) and cholecystokinin (CCK), (3) a fluorescence tracer technique involving the intraperitoneal (i.p.) injection of fluorogold, and (4) normal electron microscopy. The results showed that these neurons were distributed singly or in groups in the submucosa. They were closely adherent to the outer walls of lymphatic vessels, some appearing to protrude into the lumen. Ultrastructurally, only a thin layer of basal lamina and some collagen fibrils intervened between the endothelia of the lymphatic vessels and these neurons. Based on their synaptic contacts and the features of their content of synaptic vesicles, at least 4 types of axon terminal forming synaptic contacts with the 'lymphatic vessel-associated neurons' (LV-AN) were identified. The sources of origin of these terminals remains uncertain although it is speculated that they may be derived from vagal efferents or of intrinsic origin from the neighbouring neurons. All the LV-AN showed AChE and NSE positive reactions, but only a varying number were positive for VIP, SP, SOM, ENK, CGRP, CCK or NPY. The LV-AN were labelled with fluorogold injected i.p.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Studies of the lymphatic vessel-associated neurons in the intestine of the guinea pig. 755 16

Angiopeptin (AP: BIM23014C), a cyclic analogue of the peptide hormone somatostatin, inhibits intimal hyperplasia after balloon angioplasty. This inhibition has been attributed to a direct inhibitory effect on smooth muscle cell (SMC) proliferation. However, the SMC that proliferate in the intima and contribute to intimal hyperplasia arrive there by migrating from the injured media, suggesting that SMC migration may also play an important role in this process. Indeed, in the experiments we describe, AP inhibited the migration of rat aortic SMC cells (RA-SMC) in response to type I collagen, the predominant form of collagen in the vessel media, and did so dose dependently. RA-SMC migration was inhibited 70% in the presence of AP 100 nM. RA-SMC adhesion to type I collagen in these conditions was not inhibited, suggesting that AP does not interfere with RA-SMC recognition of type I collagen; instead, it blocks subsequent signaling events that are necessary for RA-SMC migration in response to type I collagen. AP inhibited the forskolin-stimulated accumulation of cyclic AMP by RA-SMC (35% at 30 nM). In addition, pertussis toxin (PT), which blocks Gi-mediated inhibition of adenylyl cyclase, blocked the inhibitory effect of AP on cyclic AMP (cAMP) accumulation and also blocked the inhibitory effect of AP on RA-SMC migration. These findings suggest that the inhibitory effect of AP on intimal hyperplasia is due at least in part to its effects on SMC migration and that these effects are mediated by a Gi-dependent pathway and may involve inhibition of adenylyl cyclase and cAMP accumulation.
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PMID:Angiopeptin (BIM23014C) inhibits vascular smooth muscle cell migration in vitro through a G-protein-mediated pathway and is associated with inhibition of adenylyl cyclase and cyclic AMP accumulation. 759 30

The study of intrahepatic bile duct epithelial cells (i.e., cholangiocytes) has been limited by the lack of a polarized in vitro model that allows easy access to both apical and basolateral cell surfaces. Therefore, we developed a cell line of polarized normal rat cholangiocytes (NRCs) and established conditions that produced a confluent monolayer of cells grown on collagen-coated filters of tissue culture inserts. We passaged NRCs at high density to collagen-coated, tissue-culture inserts and measured transepithelial electrical resistance. We evaluated ultrastructural features by transmission and scanning electron microscopy. gamma-glutamyl-transpeptidase (gamma GT) was visualized in cultured cells by enzyme histochemistry, and cytokeratin (CK)-7, CK-19, vimentin, and desmin staining was done by immunohistochemistry. We studied the biologic responsiveness and functional polarity of NRCs by measuring their levels of cyclic AMP after addition of forskolin with or without somatostatin to either the apical or basolateral chambers. When seeded with approximately 1 x 10(5) cells/cm2, the NRCs formed a confluent monolayer in 72 hr. Transepithelial electrical resistance increased over time, achieving a maximum of 625 (+- 25) ohms.cm2 by 1 week after confluence. Transmission and electron microscopy scanning showed the apical cell surface to be tightly packed with microvilli with a heterogeneous display of cilia ranging from none to 20 to 30 cilia/cell. On transmission, apically positioned tight junctions and vesicles were apparent; nuclei were oriented basally and the basolateral surface was characterized by membrane interdigitations. NRCs stained positively for the cholangiocyte marker proteins, gamma-glutamyl-transpeptidase, CK-7, and CK-19, and negative for the mesenchymal markers, vimentin, and desmin. Exposure of the basolateral (but not the apical) cell surface to somatostatin caused a 60% inhibition of forskolin-induced increases in intracellular levels of cyclic AMP, suggesting the presence of somatostatin receptors exclusively on the basolateral plasma membrane domain. We have developed a unique model of primary cultures of normal rat cholangiocytes in which the apical and basolateral surfaces are easily accessible; the cells develop intermediate-strength tight junctions, retain their cholangiocyte phenotype, display morphologic and functional polarity, and are responsive to hormones. This model should be useful for the assessment of vectorial transport of solutes and other constituents of blood and bile, as well as for studying growth regulation of cholangiocytes.
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PMID:Development and characterization of polarized primary cultures of rat intrahepatic bile duct epithelial cells. 856 94

Octreotide (OCT) is a somatostatin analog used for its inhibitory action on multiple GI functions. Although octreotide has numerous clinical benefits, it has also been shown to inhibit postresectional hyperplasia of small bowel and hepatic regeneration. Because octreotide inhibits both trophic and anabolic hormones, we hypothesize that the use of octreotide may be detrimental in patients with a recent bowel anastomosis. To test this hypothesis, 60 male rats were randomized to four equal groups following small bowel anastomosis. Group I = control; Group II = 10 mg/day of hydrocortisone succinate; Group III = 2.5 micrograms/kg/day octreotide (equivalent of a clinical dose); Group IV = 25 micrograms/kg/day octreotide. Hydrocortisone was used as a negative control because it is known to have inhibitory effects on small bowel anastomotic healing. On postoperative Day 7, bursting pressures were measured. Serum T-kininogen levels, as a marker for systemic inflammation, and hydroxyproline content from the anastomotic segments were obtained. These results indicate that in the rat small bowel model, octreotide did not have any deleterious effect on anastomotic strength, systemic inflammation, and collagen content, even at high doses. Hydrocortisone, as expected, showed significant detrimental effects on bursting strength, as well as decreasing systemic inflammation. These findings have significant clinical implications, as octreotide could be used without jeopardizing the intestinal anastomosis.
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PMID:The effects of octreotide on healing of small bowel anastomosis. 875 64

Treatment of diabetes mellitus by transplantation of isolated pancreatic islets could constitute an alternative to human pancreas allograft. Before transplantation, porcine islets are submitted to a procedure of isolation and purification. The quality of islets through these different steps may be assessed by morphological and functional studies. The aim of this work was the histological characterization of the four main cell types of porcine adult endocrine islets during the different steps of the isolation procedure using immunohistochemistry (IHC) applied in light (LM) and electron microscopy (EM). In fresh pancreas, islets were various sizes and shapes in LM. The number was not found different between the different portions of the pancreas. In IHC, insulin (Ins)-secreting cells accounted for the majority of the islet cells, while glucagon(Glu)-somatostatin (Som)- and polypeptide(PP)-immunoreactive cells, in decreasing number, were found in the mantle around the core of Ins-cells. In EM, B-cells contained poly-hedric granules with a dense central core and clear halo. Glu granules were spherical and very dense. D-cells and PP-cells were characterized by numerous granules, rather spherical and of inequal density for Som and more ellipsoidal for PP granules. After purification in Euroficoll, in EM, the four cellular types remained recognizable, but underwent vacuolization, mitochondrial swelling, and enlargement of intercellular spaces. After 3 days of culture on plastic dishes, as on Biopore membranes in a Millicell insert, microvilli appeared and vacuolization increased in EM. At the seventh day of culture, in EM, most of the cells were lysed in contrast to LM where at the same time, the four cell types were clearly identified by IHC but only in collagen matrix. Important discrepancies were noticed between LM and EM. This fact emphasizes the complementarity of morphological and functional studies in assessment of the quality of an islet isolation.
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PMID:Immunohistochemical and ultrastructural study of adult porcine endocrine pancreas during the different steps of islet isolation. 895 Jun 10

We recently demonstrated that cultured malignant schwannoma (MS)-derived cells can support human skin mast cell (HSMC) survival in vitro. Cultured HSMCs were spindleshaped in close contract with MS-derived cells, suggesting cell to cell interaction. To elucidate the mechanism of the enhanced HSMC survival in coculture with MS-derived cells and the cellular interactions between HSMC and MS-derived cells, we examined the immunocytochemical characteristics of MS-derived cells using immunofluorescence. Morphologically, cultured MS-derived cells were polygonal with abundant cytoplasm and resembled perineurial cells. The cultured cells immunoreacted positively with vimentin, fibronectin, laminin and collagen IV, but negatively with anti-S100 protein, anti-neuron specific enolase, and anti-neurofilament (68 kd, 145 kd, 200 kd) antibodies. MS-derived cells were distinct from Schwann cells in their lack of S100 protein and also distinguishable from endoneurial fibroblasts that produce fibronectin, but never expressed laminin or collagen IV. MS-derived cells thus possess the characteristics of perineurial cells in their general morphology and their immunocytochemical properties. Immunoreactivity for substance P (SP) and neurokinin A (NKA) was found in the cytoplasm of these cells, particularly around the nuclei. Vasoactive intestinal peptide, somatostatin, and calcitonin gene related peptide were negative. From these findings, we characterized the MS-derived cell's in vitro properties and concluded that it is similar to a perineurial cell. The extracellular matrix protein, laminin, and fibronectin expressed in the MS-derived cell might contribute to HSMC survival and morphology through cell to matrix adhesion. Neuropeptides such as SP and NKA, expressed in the MS-derived cell, might play some role in enhanced HSMC survival in vitro.
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PMID:Immunocytochemical characterization of malignant schwannoma-derived cells in culture. 904 33

We have examined the effect of alteration in cell shape on promoting differentiated morphology and physiology in cultured nonpigmented epithelial cells from the ciliary body. We have grown pure populations of nonpigmented cells on collagen gels released from the culture dish to create collagen rafts. Shortly after the gels were detached, the cells shrank in diameter and increased in height while they contracted the gel. Concurrently, the actin cytoskeleton reorganized to the cell cortex as found in vivo. After this differentiated morphology developed, large changes in intracellular Ca2+ could be elicited by simultaneous activation of acetylcholine and epinephrine or acetylcholine and somatostatin receptors as seen in intact tissue. Explant cultures of isolated nonpigmented cell layers maintained their actin distribution and also showed synergistic Ca2+ increases. Spread cells, grown on rigid substrates, had a disorganized cytoskeleton and rarely showed synergism. These data suggest that the mechanism underlying synergistic Ca2+ responses in the ciliary body is functional in nonpigmented cells grown on collagen rafts. In addition, this pathway appears to be sensitive to the disposition of the cell's cytoarchitecture.
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PMID:Functional and morphological differentiation of nonpigmented ciliary body epithelial cells grown on collagen rafts. 928 15


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