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)

Regulation of cholecystokinin (CCK) secretion was studied in conscious unrestrained rats by simultaneous duodenal perfusion with foodstuffs, intravenous infusion of hormones or neural agents, and arterial blood sampling for CCK bioassay. Duodenal infusion of casein resulted in elevation of plasma CCK from fasting level of 0.5 +/- 0.1 to 3.8 +/- 0.4 pM. Casein hydrolysate, calcium, and glucose did not elevate plasma CCK. Infusion of intact fat had a small, but nonsignificant, effect (1.4 +/- 0.4 pM), whereas infusion of oleate increased plasma CCK to 3.7 +/- 0.6 pM. Thus intact protein and fatty acids are the major dietary intestinal stimuli for CCK release in the rat. The CCK response to protein could be inhibited by somatostatin but not by peptide YY (0.2, 2, or 20 micrograms.kg-1.h-1); intravenous infusion of 1 or 10 micrograms.kg-1.h-1 somatostatin decreased casein-stimulated CCK levels to 1.5 +/- 0.2 and 0.9 +/- 0.3 pM, respectively. Stimulation of vagal discharge with 2-deoxy-D-glucose had no effect on basal or protein-stimulated plasma CCK levels; thus CCK release in the rat does not appear to be modulated by central vagal pathways. Gastrin-releasing peptide increased fasting plasma CCK levels to 1.6 +/- 0.1 pM. Administration of the cholinergic agonist bethanechol, while having no effect on fasting CCK level, inhibited protein-stimulated plasma CCK from 3.9 +/- 0.6 to 1.3 +/- 0.3 pM. Cholinergic blockade with atropine, in contrast, had no effect on basal or protein-stimulated plasma CCK. Thus CCK release is stimulated by dietary protein or fatty acid and by gastrin-releasing peptide and inhibited by somatostatin and bethanechol.
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PMID:Regulation of cholecystokinin secretion by food, hormones, and neural pathways in the rat. 197 Jul 7

The influence of PYY on stimulated gastric acid secretion and the possible role of gastric somatostatin was measured in rats. PYY, infused intravenously at a dose of 800 pmol/kg/h, reduced pentagastrin (20.8 nmol/kg/h) stimulated gastric acid secretion by 34 +/- 3%, whereas in controls acid secretion remained constant throughout the 90 min observation period. In a second series the effect of PYY on the endogenous gastric somatostatin-like immunoreactivity and gastrin-release was tested in the isolated, vascularly perfused rat stomach. PYY perfused at concentrations of 10 pM to 100 nM did not change either somatostatin or gastrin secretion from the rat stomach in vitro. The study shows that PYY suppressed acid secretion in the rat. Endogenous somatostatin or gastrin is unlikely to mediate the inhibitory effect of PYY on acid production.
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PMID:Effect of peptide YY on gastric acid secretion, gastrin and somatostatin release in the rat. 197 69

The aganglionic intestine in Hirschsprung's disease displays a severe neuronal derangement. The changes are particularly evident in the muscular innervation. In the gut the endocrine cells are among the cells known to be influenced by neurons. We have, therefore, examined the endocrine cells in ganglionic and aganglionic intestine using immunocytochemistry and immunochemistry. The endocrine cells were studied using antibodies against the neuroendocrine marker chromogranin A, the amine serotonin and the hormonal peptides somatostatin, glucagon/glicentin and peptide YY (PYY), thus covering virtually all endocrine cell types known to occur in this region. The PYY concentration in the mucosal layer was measured by radioimmunoassay. In ganglionic as well as in aganglionic intestine large populations of cells storing chromogranin A, serotonin, glucagon and PYY and a smaller population of somatostatin cells were seen. There was an increase in the density of these cells in the aganglionic intestine compared with ganglionic. The data indicate that the endocrine cell populations in the intestinal wall can be maintained despite severe derangements of the nerve supply.
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PMID:Intestinal endocrine cells in Hirschsprung's disease. No reduction in density in aganglionic compared with ganglionic segment. 197 32

We investigated the existence of an enterogastrone in rats induced by duodenal administration of oleic acid. Acid secretion by the luminally perfused stomach was stimulated in anesthetized rats by intravenous infusion of 0.3 micrograms.kg-1.h-1 pentagastrin. Intraduodenal administration of 3 mmol of oleic acid produced a profound inhibition (94%) of pentagastrin-stimulated acid output in 10 rats (P less than 0.01). Of several peptides in plasma including secretin, neurotensin, somatostatin, and peptide YY, only secretin was found to increase significantly (P less than 0.001). A similar degree of inhibition of acid output (93%) was caused by porcine secretin, 5.6 pmol.kg-1.h-1, given intravenously to mimic the plasma level of secretin produced by oleic acid infusion. The inhibitory effect of oleic acid on the acid secretion was completely reversed by intravenous injection of a rabbit antisecretin serum but not by a normal rabbit serum. These observations strongly suggest that the inhibition was mediated via circulating secretin. The inhibition produced by either oleic acid or secretin was completely blocked by indomethacin. The blocking action was completely reversed by intravenous administration of 48 micrograms.kg-1.h-1 prostaglandin E2. We conclude that endogenous secretin is a major enterogastrone released by oleic acid in anesthetized rats and that the inhibitory action of secretin requires endogenous prostaglandins.
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PMID:Mechanism of oleic acid-induced inhibition on gastric acid secretion in rats. 201 32

Somatostatin is known to inhibit the postprandial release of most gastrointestinal hormones. The aim of the present study was to evaluate the effect of an analog of somatostatin, SMS 201-995 (120 ng/kg/hr), on both meal-induced and cholecystokinin octapeptide (CCK-8, 500 ng/kg/hr)-induced peptide YY (PYY) release. Six mongrel dogs with distal ileal Thiry-Vella loops were used in this study. PYY was measured in both plasma and ileal luminal effluent. SMS 201-995 did not affect interdigestive plasma or ileal luminal PYY concentrations. CCK-8 and a fat meal both stimulated PYY release into the circulation. SMS 201-995 completely inhibited the CCK-8 and fat-stimulated circulatory release of PYY. Both CCK-8 and a mixed meal increased ileal luminal PYY recovery. SMS 201-995 inhibited CCK-8-induced, but not meal-induced, ileal luminal PYY recovery. These findings support previous studies that describe independent circulatory and ileal luminal PYY release. We conclude that both somatostatin and CCK may have a regulatory role in postprandial circulatory release of PYY.
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PMID:The effect of SMS 201-995 on meal and CCK-stimulated peptide YY release. 203 80

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

Endocrine cell types in 12 argentaffin and six argyrophil carcinoids and in nonneoplastic epithelia of the appendix vermiformis were investigated histochemically, immunohistochemically, and ultrastructurally. The nonneoplastic epithelia contained serotonin (Ser), peptide YY (PYY), glicentin (Gli), neurotensin (Neu), and somatostatin (So) cells in decreasing frequency. Out of 30 nonneoplastic Ser cells examined ultrastructurally, 28 cells were EC1 cells and two were non-EC cells. Eleven of 12 argentaffin carcinoids could be immunostained with anti-Ser serum and all of those 11 were composed almost totally of Ser cells. One of the 11 contained a small number of Neu cells. Ultrastructurally, 11 argentaffin carcinoids were composed predominantly of EC1 and/or ECn cells, and one was composed primarily of non-EC cells. Out of the six argyrophil carcinoids, five were argyrophil, non-argentaffin carcinoids; three consisted almost totally of PYY cells; one consisted of 60% PYY cells, 40% So cells and a few Gli cells; and one consisted of Ser cells alone. Ultrastructurally, the first four of those tumors were composed of D1 and/or L cells and the latter tumor was composed of ECn cells. The remaining one argyrophil carcinoid contained a few Ser-positive argentaffin cells and consisted almost totally of ECn cells which were found in both parts, with and without argentaffinity. It is concluded that the appendiceal carcinoids comprise two distinct groups on the basis of the main constituting cell type: Ser-positive, argentaffin carcinoids, composed of EC cells and peptide (especially of PYY)-positive, and Ser-negative, argyrophil non-argentaffin carcinoids of D1 and/or L cells.
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PMID:Immunohistochemical and ultrastructural studies of twelve argentaffin and six argyrophil carcinoids of the appendix vermiformis. 219 76

The Mastomys (Praomys natalensis) species are a unique natural model in which the bioactivity of gastric carcinoids may be studied. Several investigators have previously demonstrated that these tumors contain large amounts of histamine. In this study we investigated the presence of peptides associated with the neoplasm. The levels and location of gastrin, gastric inhibitory peptide (GIP), neurotensin, peptide YY (PYY), pancreatic polypeptide (PP), glucagon, bombesin, vasoactive intestinal peptide (VIP) and somatostatin (SRIF) were investigated by radioimmunoassay and immunocytochemistry. In addition the distribution of these peptides were evaluated in the gastrointestinal tract of young and old animals to investigate possible age-related changes. PYY and enteroglucagon (EG) were significantly (P less than 0.001) elevated in both tumor tissue (676 +/- 152, 551 +/- 164 pmol/g) and plasma (620 +/- 160, 500 +/- 147 pmol/l) of tumor-bearing animals. Immunocytochemistry revealed PYY- and EG-like immunoreactivity in 20-30% of tumor cells. A significant decrease (P less than 0.05) in bombesin was noted in older animals, but no changes in gastric tissue content of PYY or EG could be detected between young and old animals. Gastrin was not detected in tumors and there were no significant changes in tissue or plasma levels with age. Small bowel concentrations of VIP and PYY were higher in the older mastomys (P less than 0.05). In contrast, colonic levels of bombesin, VIP, somatostatin and PYY were significantly lower (P less than 0.05) in older mastomys compared with young. The age-related changes in several peptides may reflect an adaptive response to acid hypersecretion. The multi-hormonal character of these neoplasms suggests that these tumors develop from a pluripotential stem cell.
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PMID:Significance of gastric endocrine tumor and age-related gut peptide alterations in Mastomys. 232 98

Neuropeptide Y and peptide YY were injected into rat striatum and their effects on dopamine, serotonin and their metabolites were examined at 1 h. Neuropeptide Y induced a dose-dependent increase in dopamine turnover in the ipsilateral striatum with no effect on serotonin turnover. When neuropeptide Y was coinjected with somatostatin there was an additive effect in increasing dopamine turnover. There was no alteration in striatal concentrations of gamma-aminobutyric acid, glutamate, or aspartate with either neuropeptide Y or somatostatin injections. These results suggest that neuropeptide Y may play a role with somatostatin in regulating striatal dopaminergic transmission.
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PMID:The effect of neuropeptide Y on striatal catecholamines. 243 56

Five argyrophil, non-argentaffin classical carcinoids of the appendix were found in 19 appendiceal classical carcinoids and were investigated histochemically, immunohistochemically and ultrastructurally. All tumors consisted entirely of argyrophil cells. Three of the five carcinoids were composed almost totally of peptide YY cells and were negative for serotonin. One of them consisted of peptide YY cells (60%), somatostatin cells (40%), and a few cells with glucagon-like immunoreactivity (GLI). The remaining one without peptides was homogeneously immunoreactive for serotonin alone. Ultrastructurally, each of the four peptide-positive carcinoids was composed of one kind of endocrine cell type with round secretory granules. Average diameter of granules were 150, 160, 190, and 210 nm, respectively. The non-argentaffin, serotonin-positive carcinoid showed predominant round secretory granules and a few irregular ones, both being 150 nm in largest diameter. It is suggested that the argyrophil, non-argentaffin carcinoids of the appendix are subdivided into two groups; carcinoids composed mainly of peptide (especially, peptide YY)-positive cells with round granules of D1 and/or L cell type and those of serotonin-positive cells with pleomorphic granules of ECn cell type.
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PMID:Argyrophil, non-argentaffin carcinoids of the appendix vermiformis. Immunohistochemical and ultrastructural studies. 244 67


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