Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01350 (gastrin)
 9,683 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Serotonin-producing pancreatic endocrine tumours are rare neoplasms which in most cases exhibit malignant biological behaviour. These tumours, in the majority of the well-documented cases, are composed of argyrophil- and argentaffin-positive cells which contain large pleomorphic neurosecretory granules. In contrast, argyrophilic non-argentaffin pancreatic endocrine tumours with tumour cells containing round neurosecretory granules are exceptional. In this study we describe such a tumour not associated with clinical evidence of carcinoid syndrome in a 60-year-old woman. Histological examination revealed tumour extension in pancreatic lymphatic vessels and veins but no evidence of locoregional or distant metastases. Ten months after surgery the patient showed no recurrence of the disease. Immunohistochemistry revealed cytoplasmic serotonin production in the tumour cells which were negative for anti-gastrin, insulin, glucagon, somatostatin, pancreatic polypeptide (PP), vasoactive intestinal peptide (VIP) and ACTH. This study emphasizes the usefulness of combined ultrastructural and immunohistochemical investigations in order to identify and characterize the rare pancreatic endocrine tumours with serotonin production.
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PMID:Serotonin-producing pancreatic endocrine tumour. Histological, ultrastructural and immunohistochemical study of a case. 196 80

The suprachiasmatic nucleus (SCN), which appears to act as a circadian clock, contains a subpopulation of local circuit neurons in which vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI), and gastrin releasing peptide (GRP) are colocalized. To determine whether VIP, PHI, and GRP interact within the SCN to produce a signal important for circadian control, the behavioral and cellular effects of coadministration of these neuropeptides were investigated. Coadministration of VIP, PHI, and GRP within the SCN mimicked the phase-delaying effects of light on circadian control following in vivo microinjection and activated SCN single units recorded in vitro. These behavioral and cellular effects of coadministration of VIP, PHI, and GRP were significantly greater than administration of VIP, PHI, or GRP alone or coadministration of any 2 of these peptides. These data illustrate a new mechanism whereby multiple, colocalized neuropeptides interact in a functionally significant manner, and indicate that the interaction of VIP, PHI, and GRP may be involved in the regulation of circadian rhythms by the SCN.
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PMID:Interaction of colocalized neuropeptides: functional significance in the circadian timing system. 200 63

Hirschsprung's disease (Megacolon congenitum) is characterized by a sustained contraction of a segment of the large intestine and a consequent enlargement of the preceding gut segment. Morphologically, Hirschsprung's disease is characterized by an absence of neuronal cell bodies in the intramural ganglia of the contracted segment. An additional characteristic finding is the presence of enlarged nerve trunks in the submucosa and in the layer separating the circular and longitudinal muscle layers. These nerve trunks contain abundant acetylcholine esterase (AChE)-positive nerve fibers. The nerve fiber hyperplasia together with an increased amount of acetylcholine as well as AChE activity in the aganglionic segment suggests a cholinergic hyperinnervation. There are other reports claiming an adrenergic hyperinnervation in the aganglionic segment. Recent studies on the peptidergic innervation of the afflicted intestinal segment have demonstrated marked reduction in the density of nerve fibers storing vasoactive intestinal peptide (VIP), substance P (SP), enkephalin and gastrin releasing peptide (GRP). The frequency of nerve fibers storing calcitonin gene-related peptide (CGRP) and galanin seems less affected. Interestingly, nerve fibers storing neuropeptide Y (NPY) are more frequent than normally in the aganglionic segment, the circular muscle being penetrated by numerous NPY-containing nerve fibers. Thus, neuropeptides have turned out to be interesting and promising new markers in the histochemical diagnosis of Hirschsprung's disease. Other possibilities for the histochemical diagnosis includes the immunocytochemical demonstration of general neuronal markers such as neurospecific enolase (NEC), neurofilament and chromogranins. Techniques demonstrating the cholinergic and adrenergic hyperinnervation in the aganglionic intestine such as AChE staining and staining for adrenergic nerves are also of interest for the diagnosis.
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PMID:Neuronal markers in Hirschsprung's disease with special reference to neuropeptides. 208 Feb 35

In recent years, the localization and physiological significance of vasoactive intestinal peptide (VIP) in various organs have been studied. Investigations of the significance of VIP in the ovary have been done, but the detailed mechanism of action is still unknown. We made in vitro studies of VIP using rat ovaries. Ovarian granulosa cells were collected after treatment with estrogen in immature hypophysectomized rats. Luteal cells were collected from immature rats treated with pregnant mare serum (PMS) and human chorionic gonadotropin (hCG). These cells were cultured in a serum free medium for 48 hr in the absence or presence of various amounts of VIP. We determined the amount of steroids produced in the culture medium by specific RIA. Activities of 3 beta-HSD in the granulosa cells were determined by the amount of progesterone formed from labelled pregnenolone. Induction of LH-receptor in the granulosa cells by VIP and VIP-receptor in these cells was investigated. VIP stimulated estrogen and progesterone production dose and time dependently with an approximate ED50 value of 3 x 10(-8) M. The amount of cyclic adenosine monophosphate (c-AMP) was similarly increased. VIP enhanced 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) activity when incubated with the granulosa cells for 24 hours. VIP stimulated the granulosa cells in a way similar to follicle stimulating hormone (FSH), but the stimulating effect was slightly less than that of FSH. Unlike FSH, VIP did not induce LH-receptor. The binding of 125I-VIP with the granulosa cells was blocked, dose dependently, by unlabelled VIP, suggesting the presence of VIP-receptor in the granulosa cells. Another peptide, PHM-27, stimulated the granulosa cells although its potency was less than that of VIP. In contrast, gastrin, CCK and secretion did not stimulate the granulosa cells at all. According to the present study. VIP did not exert any effect on the luteal cells, and progesterone production in vitro was not stimulated by this peptide. The VIP effects seem to be at least partly c-AMP dependent and may be mediated through the VIP-receptor in the granulosa cells. The observed direct effects of VIP suggest that it may act as a local hormone to regulate the ovarian function.
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PMID:[The effect of vasoactive intestinal peptide on the rat ovary]. 217 Feb 9

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

The ileocaecal junctions of 5 horses and 2 donkeys were examined by using antisera to the following peptides: somatostatin, glucagon, gastrin, neurotensin, vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI), calcitonin gene-related peptide (CGRP), substance P (SP) and neuropeptide Y (NPY). Antisera to somatostatin, neurotensin and NPY demonstrated endocrine cells in the ileal- and caecal parts of the ileocaecal junction, while immunoreactivity for glucagon was demonstrated in endocrine cells of the ileal part only. Nerve cell bodies showing immunoreactivity to SP, VIP, CGRP and PHI were demonstrated in the myenteric and submucosal plexuses and were associated with small blood vessels in the submucosa of all the regions tested. Ramified nerve fibres in the submucosa immunoreactive to SP, VIP, CGRP and PHI extended to the mucosa and to small blood vessels in the submucosa. Nerve fibres showing immunoreactivity to SP, VIP and PHI extended to the circular smooth muscle layer of the ileocaecal junction.
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PMID:An immunohistochemical study of various peptide-containing endocrine cells and neurones at the equine ileocaecal junction. 233 94

An immunocytochemical method was used for localization of various peptide-like substances in the Ascaris nervous system. Out of 45 antipeptide antisera, 12 demonstrated immunoreactivity in different subsets of neurons; these 12 antisera were raised against luteinizing hormone-releasing hormone (LHRH), Aplysia peptide L11 (L11), Aplysia peptide 12B (12B), small cardioactive peptide B (SCPB), neuropeptide Y (NPY), FMRFamide, gastrin-17, cholecystokinin octapeptide (CCK-8), alpha-melanocyte stimulating hormone (alpha MSH), calcitonin gene related peptide (CGRP), corticotropin releasing factor (CRF), and vasoactive intestinal peptide (VIP). Several peptide-like substances were colocalized to the same neuron. Our results suggest that Ascaris, like other organisms, contains multiple peptidergic systems.
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PMID:Neuropeptide diversity in Ascaris: an immunocytochemical study. 234 16

The gastrointestinal tract harbors several populations of peptide containing nerve fibers. Among the gut neuropeptides are vasoactive intestinal peptide (VIP), substance P, enkephalin, and gastrin releasing peptide (GRP). We have examined specimens from five patients with pyloric stenosis and from five controls immunocytochemically with respect to the density of nerve fibers containing VIP, substance P, enkephalin, or GRP. In the control specimens VIP and enkephalin fibers were fairly numerous, whereas substance P and GRP fibers were few. In the pyloric stenosis patients the density of VIP fibers and enkephalin fibers was reduced in the smooth muscle. In the myenteric ganglia there was no such reduction. Substance P and GRP fibers were rare as in controls. The results indicate a reduction of VIP and enkephalin fibers in smooth muscle in pyloric stenosis patients and may be interpreted to support the view that an impaired neuronal function is involved in the pathophysiology of pyloric stenosis.
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PMID:Peptidergic innervation in infantile hypertrophic pyloric stenosis. 242 40

The effect of a milk substitute diet containing concentrated soya protein on secretory functions of the abomasum and pancreas and on plasma concentrations of gut hormones and soya antibodies was studied. Sixteen calves aged 12-19 weeks were given a milk substitute in which a major part of the protein source was either soya concentrate (soya diet) or skim milk (control diet). The soya diet was prepared by hot aqueous ethanol extraction of soya bean meal to remove oligosaccharides and inactivate antigenic constituents. Circulatory IgG antibodies against soya proteins were found in all of the calves when they were 16 weeks of age. Their titres increased slightly between 16 and 19 weeks, irrespective of the diet. It seems unlikely that the presence of these antibodies was related specifically to the feeding of the soya concentrate. At slaughter the weight of the gastric mucosa and pancreas and quantities of pancreatic protein together with specific activities of trypsin and chymotrypsin were significantly lower (17, 20, 16, 30 and 36%, respectively) with the soya diet. The quantities of enzymes in the gastric mucosa or the specific activity of pancreatic amylase were not affected, whereas that of lipase increased by 26%. Total enzyme activities as well as units per kg live weight gave significant differences only for trypsin and chymotrypsin which were reduced by 43 and 38%, respectively. With the soya diet, fasting concentrations of gastric inhibitory peptide (GIP) and secretin in plasma samples were significantly lower (49 and 34%, respectively). Values of GIP were also lower (54%) 1 h after feeding. In contrast, postprandial values of cholecystokinin (CCK) were 1.4 times greater. No significant differences were found between the two diets for gastrin, vasoactive intestinal peptide (VIP), bovine pancreatic polypeptide (BPP), somatostatine and motilin. In general these observations could be explained, in part, by the more rapid passage of protein and fat from the abomasum to the duodenum following feeds containing soya concentrate. However, these differences in concentrations of gut hormones did not seem to be related to variations in the weights of gastric mucosa and pancreas or activities of pancreatic enzymes.
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PMID:Effect of soya protein on digestive enzymes, gut hormone and anti-soya antibody plasma levels in the preruminant calf. 242 2

Dopamine has been shown to effect pancreatic flow, protein output and amylase secretion in a variety of species. However, there is conflicting evidence regarding the role of dopamine on amylase release in vitro. Specific studies were conducted to evaluate the effect of dopamine and to compare its effects with other substances on basal- and secretagogue-stimulated amylase secretion in a guinea pig dispersed pancreatic acinar cells preparation. Dopamine (10(-6) M) induced a small, but significant (P less than 0.05) increase of amylase secretion. Established secretagogues (10(-6) M) including bombesin, cholecystokinin-octapeptide (CCK-8) and carbachol as anticipated induced significantly larger responses. Other substances tested (10(-6) M) including thyrotropin-releasing hormone (TRH) and muscimol were without effect. Complete dose-response studies (10(-11)-10(-3) M) in the presence of bombesin, CCK-8 and carbachol revealed that dopamine does not affect amylase release in response to these secretagogues. These findings suggest that dopamine is a weak stimulant of amylase secretion in vitro, and that it may therefore play a minor role in regulation of pancreatic enzyme secretion. Several factors including vascular, hormonal and neural have been implicated in regulation of pancreatic exocrine secretion. In particular, autonomic nervous system activity, notably cholinergic, has been shown to affect the secretory status of the pancreatic acinar cell. In addition, several biologically active peptides including bombesin, cholecystokinin (CCK), secretin, vasoactive intestinal peptide (VIP), substance P, gastrin and stimulation of cholinergic (muscarinic) receptors with carbachol have been shown to stimulate pancreatic enzyme secretion both in vivo and in vitro. Certain controversy regarding the role of the sympathetic nervous system in regulation of pancreatic exocrine secretion does exist. For example, several studies with agonists and antagonists of noradrenergic and dopaminergic receptor subtypes suggest a stimulatory effect on pancreatic fluid, electrolyte and enzyme secretion. However, these responses are species-specific and variations inherent to the model have been described. Dopamine administration has been shown to stimulate pancreatic bicarbonate and enzyme secretion in a variety of species including mice, dogs, and man. Radioligand binding studies with 3H-dopamine have revealed the presence of high- and low-affinity dopamine binding sites in dog pancreatic acinar cells. Stimulation of these receptors has been correlated with dose-dependent increases in intracellular cAMP levels.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Effect of dopamine on amylase secretion from guinea pig pancreatic acinar cells in vitro. 247 35


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