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

Bombesin-like immunoreactivity (BLI), a putative peptidergic neurotransmitter of the gastrointestinal intrinsic nervous system is released from the isolated perfused rat stomach in response to the classical neurotransmitter acetylcholine and in response to other putative peptidergic neurotransmitters such as vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI) or growth hormone releasing factor (GRF). The secretion of BLI is modulated not only by gastric factors such as the intragastric pH but also by changes of perfusate glucose concentrations indicating that alterations of carbohydrate metabolism might have an effect on gastric neuroendocrine regulation. Since previous studies have shown that insulin, the major regulatory hormone of glucose metabolism, reduces gastric somatostatin and glucagon secretion it was of interest to determine the effect of insulin on gastric BLI and gastrin secretion. The experiments were performed in the isolated perfused rat stomach model. The addition of porcine insulin to the perfusate at concentrations of 50 and 100 microU/ml had no effect on basal BLI and gastrin secretion. The infusion of acetylcholine (2 X 10(-6)M and 4 X 10(-6)M) elicited a stimulation of BLI and gastrin secretion which was not altered by the addition of insulin (100 microU/ml). On the other hand, significant effects of insulin were observed during administration of the two putative peptidergic neurotransmitters VIP and leu-enkephalin. The infusion of VIP at 10(-11)M and 10(-8)M had no effect on BLI and gastrin secretion in the absence of insulin, however, with the addition of insulin (100 microU/ml) the higher dose of VIP (10(-8)M) elicited a significant stimulation of BLI secretion while both doses of VIP (10(-11)M and 10(-8)M) significantly increased gastrin release. Similar to VIP the infusion of leu-enkephalin at doses of 10(-9)M and 10(-6)M had no effect on BLI and gastrin secretion in the absence of insulin. When insulin was added to the perfusate both doses of leu-enkephalin elicited a significant stimulation of BLI secretion while gastrin remained unchanged. The addition of the specific opiate receptor antagonist naloxone (10(-5)M) did not block the effect of leu-enkephalin in the presence of insulin. In addition the effect of naloxone was also examined during cholinergic stimulation. The addition of naloxone (10(-5)M) during the infusion of acetylcholine abolished the stimulatory effect on BLI secretion in the absence of insulin, whereas in the presence of insulin naloxone did not alter cholinergically-induced BLI secretion.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Effect of insulin on secretion of bombesin-like immunoreactivity and gastrin from the isolated rat stomach in response to acetylcholine, VIP and leucine-enkephalin. 351 44

Intestinal hyperperistalsis is one part of the clinical picture in infantile colic. Three gut hormones involved in the regulation of gut motility; motilin, vasoactive intestinal peptide (VIP) and gastrin, were measured with the RIA method in: 40 infants with infantile colic, (age 2-22 weeks), 42 healthy age-matched infants, 11 children (age 3-36 months) with gastrointestinal disorders, and 20 children (age 3-36 months) with non-gastrointestinal disorder. Basal s-motilin levels were raised in infants with infantile colic (p less than 0.01) and in children with other gastrointestinal disorders (p less than 0.001). Formula-fed infants had higher basal s-motilin levels than the breast-fed infants (p less than 0.05). P-VIP and s-gastrin levels were raised in children with other gastro-intestinal disorders (p less than 0.05), but not in infantile colic. Formula-fed colicky infants had higher s-gastrin levels than the breast-fed colicky infants (p less than 0.05). We suggest that the increased s-motilin level in infantile colic might account in part for the clinical picture of this disorder.
 ...
PMID:Motilin, vasoactive intestinal peptide and gastrin in infantile colic. 359 Dec 97

Previous studies have demonstrated mostly inhibitory effects of elevated plasma glucose levels on gastric exo- and endocrine as well as motor functions. Because increased plasma glucose levels reduce vagal activity via the central nervous system, it remains unclear if glucose exerts a direct effect on gastric functions. Therefore, our study was designed to determine the effect of acute changes in glucose concentrations on the release of gastrin and bombesin-like immunoreactivity (BLI) from the isolated perfused rat stomach. Acute elevations of perfusate glucose from 100 to 200 mg/dl or from 100 to 300 mg/dl augmented BLI secretion significantly without affecting gastrin release. During an acute decrease from 200 to 30 mg/dl, the secretion of both peptides remained unchanged. When acetylcholine was administered to stimulate BLI and gastrin secretion, the elevation of perfusate glucose to 200 mg/dl and the decrease to 30 mg/dl attenuated BLI secretion, whereas gastrin secretion remained unchanged compared with the control experiments at 100 mg/dl glucose. On the other hand, the perfusion of vasoactive intestinal peptide (VIP) and Leu-enkephalin had no effect on BLI and gastrin secretion during 100 mg/dl glucose perfusion, but both peptides elicited a significant stimulatory effect on BLI secretion during a perfusate glucose concentration of 200 mg/dl without affecting gastrin secretion. In conclusion, our study demonstrates first that an acute increase of glucose augments basal BLI secretion. Second, cholinergically induced BLI secretion is attenuated by hypo- and hyperglycemia. Third, hyperglycemia augments BLI secretion in response to the neuropeptides VIP and Leu-enkephalin. Fourth, basal and stimulated gastrin secretion remains unchanged during acute alterations of perfusate glucose levels.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Modulatory glucose effect on bombesin-like immunoreactivity and gastrin secretion from isolated perfused rat stomach. 372 Oct 63

Peptide YY (PYY) is a 36 amino acid peptide produced by mucosal endocrine cells of the ileum and colon which inhibits acid secretion and intestinal transit in man. To assess its effects on metabolites and digestive hormones PYY was infused into 18 fasting normal subjects at three dose levels (0.06, 0.19, and 0.57 pmol kg-1 min-1), each for a period of 1 h. During the infusions mean plasma PYY levels increased by 8, 25, and 73 pmol/liter, respectively. The mean disappearance half-time on stopping the infusions was 9.2 +/- 0.4 (SEM) min. The mean MCR was 7.3 +/- 0.7 ml kg-1 min-1 and the apparent volume of distribution was calculated to be 94 +/- 9 ml kg-1. During the highest dose infusion there was a significant increase in both systolic and diastolic blood pressure, of 8.6 +/- 3.7 mmHg (P less than 0.05) and 10.9 +/- 3.0 mmHg (P less than 0.01), respectively. PYY caused a significant 50% reduction in plasma pancreatic polypeptide concentrations (P less than 0.05) and a 55% reduction in circulating motilin levels (P less than 0.05). PYY had no significant effect on circulating concentrations of insulin, glucagon, gastrin, gastric inhibitory peptide, neurotensin, enteroglucagon, or vasoactive intestinal peptide. PYY also had no significant effect on circulating concentrations of glucose, lactate, glycerol, or nonesterified fatty acids. This recently discovered human intestinal hormonal peptide thus has significant effects both on gastrointestinal hormones (motilin and pancreatic polypeptide) and blood pressure in man, but appears not to influence glucose or lipid metabolism.
 ...
PMID:Peptide YY kinetics and effects on blood pressure and circulating pancreatic and gastrointestinal hormones and metabolites in man. 375 28

Effects of microelectrophoretic application of cholecystokinin-8, gastrin-17, vasoactive intestinal peptide and secretin on activities of septal-preoptic neurons were examined in ovariectomized rats. All of the 4 peptides produced either excitatory or inhibitory responses in some neurons tested. No consistent relationship was observed between effects of different peptides, even between the peptides of the same family. These results provide electrophysiologic evidence for the action in the septal-preoptic region of these peptides, and suggest that there may be specific interneurons sensitive to a corresponding peptide with some overlapping.
 ...
PMID:Septal-preoptic unit responses to microelectrophoresis of cholecystokinin, gastrin, vasoactive intestinal peptide and secretin in the rat. 377 98

Gastric acid secretion is known to be controlled by a complex system of interacting factors. Amongst these, regulatory peptides make a significant contribution. In the present study, immunocytochemistry and radioimmunoassay were used to investigate gastric regulatory peptides in animals with pharmacologically reduced gastric acid secretion. Increased numbers of densely immunostained antral gastrin-immunoreactive (G) cells were seen in rats which had been rendered virtually achlorhydric by administration of high-dose (400 mumol/kg daily) omeprazole over a 10-week period. These morphological changes were accompanied by increases in the plasma, antral and fundic concentrations of gastrin, as measured by radioimmunoassay. In contrast, antral somatostatin-containing cells were reduced, and there was a corresponding fall in the tissue content of the peptide. Ten weeks after treatment had ceased, the peptide profiles had returned to normal. No other regulatory peptide, whether endocrine or neural, appeared to alter during treatment with high-dose omeprazole. Treatment with high-dose (700 mumol/kg daily) ranitidine also caused an elevation in the G cell population and the antral and plasma content of gastrin, but to a lesser extent than that observed during omeprazole treatment. Somatostatin cells and tissue levels did not alter in these animals, and no other morphological changes could be detected. Radioimmunoassay, however, measured reduced quantities of vasoactive intestinal peptide, peptide histidine isoleucine and calcitonin gene-related peptide. Achlorhydria, induced by omeprazole at a dosage of 250-500 times that required for effective acid inhibition in man and animals, therefore resulted in reciprocal changes in gastrin and somatostatin cells. These changes are support for the postulated roles of these peptides in the control of gastric acid secretion.
 ...
PMID:Gastric regulatory peptides in rats with reduced acid secretion. 379 73

The gastric autonomic innervation of the dogfish was examined for regulatory peptides and serotonin by immunochemical techniques. Bouin's-fixed, paraffin-embedded or benzoquinone-fixed frozen sections were used for light microscopical immunocytochemistry and glutaraldehyde-fixed resin-embedded sections for electron microscopical immunocytochemistry. Bombesin-, somatostatin-, gastrin/cholecystokinin-, substance P-, peptide histidine isoleucine-, vasoactive intestinal peptide- and serotonin-immunoreactive nerves were found in all layers of the stomach wall. Bombesin and vasoactive intestinal peptide-containing nerves were identified at ultrastructural level. Radioimmunoassay of acetic acid extracts of tissue confirmed the presence of immunoreactivity for bombesin, somatostatin, substance P, peptide histidine isoleucine and vasoactive intestinal peptide. Reverse phase high performance liquid chromatography indicated that the peptides identified were broadly similar to their mammalian counterparts.
 ...
PMID:Neuropeptides and 5-HT immunoreactivity in the gastric nerves of the dogfish (Scyliorhinus stellaris). 391 13

Intracellular recording methods were used to study the actions of bombesin, gastrin releasing peptide and vasoactive intestinal peptide on electrical behavior of AH/Type 2 myenteric neurons in guinea-pig ileum in vitro. Each peptide evoked membrane depolarization associated with increased input resistance, enhanced excitability and suppression of hyperpolarizing after-potentials. The effects of the peptides simulated slow synaptic excitation in the myenteric plexus and are consistent with a neurotransmitter or neuromodulatory function.
 ...
PMID:Bombesin, gastrin releasing peptide and vasoactive intestinal peptide excite myenteric neurons. 404 29

Immunohistochemical studies using an antiserum to a pure porcine vasoactive intestinal peptide, possessing no cross reactivity against the related hormones glucagon, secretin, and gastrin-inhibitory peptide, revealed a wide distribution of vasoactive intestinal peptide cells throughout the entire length of the mammalian and avian gut. The highest numbers of cells were present in the small intestine and more particularly in the large intestine in all species investigated. Three types of endocrine cell in the mammalian gut are sufficiently widely distributed to be considered as the sites for production of vasoactive intestinal peptide. In the avian gut there are only two identifiable cell types. Sequential immunofluorescence and silver staining showed, in the bird, that the enterochromaffin (EC) cell was not responsible. This procedure could not be used in our mammalian gut samples but here serial section immunofluorescence for enteroglucagon and vasoactive intestinal peptide indicated that the two cells were not identical and that each was differently localized in the mucosa. These results leave the D cell of the Wiesbaden classification as the most likely site for the production of vasoactive intestinal peptide. The final identification must come from successful immune electron cytochemistry but this has not yet been achieved.
 ...
PMID:Cellular localization of a vasoactive intestinal peptide in the mammalian and avian gastrointestinal tract. 461 59

Historically, the enterochromaffin cell was the first endocrine cell type detected in avian gut; subsequently, a number of types of such cells were distinguished on the basis of the ultrastructural features of the secretory granules. More recently, immunocytochemical procedures have revealed somatostatin-, pancreatic polypeptide (PP)-, polypeptide YY-, glucagon-, secretin-, vasoactive intestinal peptide (VIP)-, gastrin-, cholecystokinin-, neurotensin-, bombesin-, substance P-, enkephalin-, motilin-, and FMRFamide-like immunoreactivity in avian gastrointestinal endocrine cells. Most endocrine cells are located in the antrum; there are a number in the proventriculus and small intestine but few in the gizzard, cecum, and rectum. Several avian gastroenteropancreatic hormones, including glucagon, VIP, secretin, bombesin, neurotensin, and PP, have been isolated and sequenced. They resemble the equivalent mammalian peptides in terms of molecular size but differ in amino acid composition and sequence; some (e.g., VIP) differ only in minor respects, others (e.g., secretin) more radically. Gastrointestinal endocrine cells appear late in development; available data indicate that few types are recognized by either immunocytochemistry or electron microscopy before 16 days of incubation. Experimental evidence has shown that at least the majority of gut endocrine cells are of endodermal origin and are not derived from the neural crest or neuroectoderm as earlier proposed. In early embryos, the progenitors of gastrointestinal endocrine cells are more widespread than are the differentiated cells in chicks at hatching. This, along with other observations, raises the question of factors that might influence the differentiation of gut endocrine cells.
 ...
PMID:Gastrointestinal hormones in birds: morphological, chemical, and developmental aspects. 608 44


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>