Pyloric Mucosa Research Articles

Expression of claudins in the normal canine gastric mucosa

The aim of the present study was to investigate the expression pattern of claudin-1, -2, -3, -4, -5, -7, -8, -10 and -18 in the intact fundic and pyloric gastric mucosa of dogs. Intense, linear, membranous claudin-18 positivity was detected in the surface gastric cells and in the epithelial cells of the gastric glands both in the fundic and pyloric stomach regions. The mucous neck cells in the apical part of the glands, furthermore the parietal cells and chief cells of the basal part of the gland were all positive for claudin-18, in the same way as the enteroendocrine cells. Cells of the basal part of the pyloric glands showed intense, linear, membranous claudin-2 positivity, but cells of the superficial portion of these glands and the surface gastric cells in this region were claudin-2 negative. Fibroblasts, endothelial cells, lymphocytes of the propria layer, smooth muscle cells and vegetative neurons were all negative for claudin-2. All gastric epithelial cells were negative for claudin-1, -3, -4, -5, -6, -7, -8 and -10. The endothelial cells of the propria layer had intense claudin-5 positivity. We assume that claudin-18 forms a paracellular barrier against gastric acid in the healthy canine stomach, in the same way as in mice.

Effect of free thymol on differential gene expression in gastric mucosa of the young pig

Thymol is the most common molecule in thyme and has been proposed as an oral alternative to antibiotics in the feed of pigs and broilers. The knowledge of the in vivo physiological effects of thymol on tissues is limited, particularly its impact on the gastric mucosa, where it is primarily absorbed when it is orally supplied. In this study, thymol (TH, 50 mg/ kg BW) or a placebo (CO) was introduced directly into the stomach of 8 weaned pigs that were slaughtered 12 h later and sampled for gastric oxyntic and pyloric mucosa. The analysis of whole transcript expression was performed using Affymetrix© Porcine Gene 1.1 ST array strips. Affymetrix Transcripts IDs were associated with 13 406 human gene names based on Sus scrofa Ensemble. Gene Set Enrichment Analysis was performed, comparing TH and CO pigs. For each gene set, the normalized enrichment score (NES) was defined as significant when the false discovery rate % was <25 and the P-value of NES was <0.05. In response to TH, 72 and 19 gene sets were significantly enriched in the oxyntic and pyloric mucosa, respectively. Several gene sets involved in mitosis and its regulation ranked near the top, primarily in the oxyntic mucosa; the gene set DIGESTION ranked first and ninth in the pyloric and oxyntic mucosa, respectively. Within this group, somatostatin (SST), SST receptors, peptide transporter 1 (SLC15A1) and calpain 9 (gastrointestinal tract-specific calpain) were the most strongly upregulated genes. Thymol reduced the enrichment of 120 and 59 gene sets in the oxyntic and pyloric mucosa, respectively. Several gene sets related to ion transport and channeling and aqueous pores across membranes, including short transient receptor potential (TRP) channel 4, potassium voltage-gated channel members 1 and 2, and ryanodine receptors 2 and 3, were less enriched. The downregulation of these genes sensitive to thymol in vitro could depend on the thymol dose and contact with the gastric tissues that causes an adaptive response with their reduced activation. Conversely, the activation of the TRPA1 gene (ranked 1072 and 128 among all the genes in the oxyntic and pyloric mucosa, respectively) indicates the involvement of another TRP-regulating cellular calcium storage. In conclusion, the stimulation of gastric proliferative activity and the control of digestive activity by thymol can influence positively gastric maturation and function in the weaned pigs. These properties should be considered in addition to thymol’s antimicrobial properties when supplementation of this molecule in feed is evaluated.

O34 Adaptation intestinale consécutive à une résection étendue de l’intestin grêle et d’une partie du côlon chez le rat

The immunohistochemical detection of six distinct sequences of proglucagon and its derivatives (GRPP, glicentin, glucagon-37, glucagon-29, GLP1, GLP2 and MPGF) in both intestinal L cells and pancreatic or gastric A cells of some mammals (dog, man, guinea pig) confirms that the two cell types produce the same proglucagon molecule, although the final step of its post-translational processing differs in the two cells. Immunohistochemical and ultrastructural patterns of glucagon glicentin cells in the pancreas of lower vertebrates and early human fetuses, as well as tumor cell studies, suggest an evolution of gastropancreatic A cells from L cells. On the contrary, the PP-related peptide PYY of intestinal L cells, and PP with its C-terminal icosapeptide extension of pancreatic PP cells, likely originate from different prohormones. Although intermediate patterns of peptide expression can be observed, including some F-type PP cells of the dog pancreas (uncinate process) and pyloric mucosa showing PYY immunoreactivity or rare PYY and/or HPP immunoreactive cells of the human rectum lacking glicentin reactivity, no obvious relationship can be established between L cells and pancreatic (F-type) PP cells. However, some evolutionary, embryogenetic and oncogenetic link may exist between L cells and human D1-type PP cells, a minor population of PP cells scattered in the pancreatic tissue of dorsal pouch origin and a major fraction of tumor PP cells.

Late administration of a specific COX-2 inhibitor does not treat and/or prevent progression of gastric tumors in rats submitted to duodenogastric reflux procedure

To assess whether late introduction of a specific COX-2 inhibitor (Meloxicam) can treat and/or prevent the progression of tumors in the stomach of rats submitted to duodenogastric reflux. Seventy five male Wistar rats, weighing 150 grams, were submitted to the induction of duodenogastric reflux through the pylorus. At 36 weeks of follow-up were established three experimental groups: DGR36 sacrificed immediately, DGR54 and DGR54MLX both sacrificed at 54th week of follow-up . The animals of the latter group were fed with a rat chow premixed with Meloxicam (2.0 mg/ kg feed; 0.3 mg / kg bw / day) and the other two with standard rat chow. The lesions found in the pyloric mucosa and gastrojejunal anastomosis were analyzed macroscopically and histologically. For statistical analysis was adjusted a generalized linear model assuming a binomial distribution with LOGIT link function. No significant differences were found when comparing the incidences of benign tumor lesions (Adenomatous Hyperplasia), p=0.4915, or malignant (Mucinous Adenocarcinoma), p=0.2731, among groups. Late introduction of specific COX-2 inhibitor (Meloxicam) did not treat and was not able to prevent the progression of tumoral lesions induced by duodenogastric reflux in the rat stomachs.

Lack of cholinergic innervation in gastric mucosa does not affect gastrin secretion or basal acid output in neurturin receptor GFRα2 deficient mice

Efferent signals from the vagus nerve are thought to mediate both basal and meal-induced gastric acid secretion, and provide trophic support of the mucosa. However, the underlying mechanisms are incompletely understood. Neurturin, signalling via glial cell line-derived neurotrophic factor (GDNF)-family receptor α2 (GFRα2), is essential for parasympathetic innervation of many target tissues but its role in gastric innervation is unknown. Here we show that most nerve fibres in wild-type mouse gastric mucosa, including all positive for gastrin-releasing peptide, are cholinergic. GFRα2-deficient (KO) mice lacked virtually all cholinergic nerve fibres and associated glial cells in the gastric (oxyntic and pyloric) mucosa but not in the smooth muscle, consistent with the selective expression of neurturin mRNA in the gastric mucosa. 2-Deoxyglucose and hexamethonium failed to affect acid secretion in the GFRα2-KO mice indicating the lack of functional innervation in gastric mucosa. Interestingly, basal and maximal histamine-induced acid secretion did not differ between wild-type and GFRα2-KO mice. Moreover, circulating gastrin levels in both fasted and fed animals, thickness of gastric mucosa, and density of parietal and different endocrine cells were similar. Carbachol-stimulated acid secretion was higher in GFRα2-KO mice, while atropine reduced basal secretion similarly in both genotypes. We conclude that cholinergic innervation of gastric mucosa depends on neurturin-GFRα2 signalling but is dispensable for gastrin secretion and for basal and maximal acid output. Basal acid secretion in the KO mice appears to be, at least partly, facilitated by constitutive activity of muscarinic receptors.

Rebamipide induces dendritic cell recruitment to N-methyl-N′-nitro-N-nitrosoguanidine (MNNG)-exposed rat gastric mucosa based on IL-1β upregulation

Rebamipide is usually used for mucosal protection, healing of gastric ulcers, treatment of gastritis, etc., but its effects on gastric malignancy have not been elucidated. Using Lewis and Buffalo rat strains treated with peroral administration of N-methyl-N′-nitro-N-nitrosoguanidine (MNNG), we evaluated the effect of rebamipide on the induction of tumor-suppressive dendritic cells, which are known to be heterogeneous antigen-presenting cells of bone marrow origin and are critical for the initiation of primary T-cell responses. Using CD68 as a marker for dendritic cells, the stomach pyloric mucosae of Lewis and Buffalo rats were immunohistochemically analyzed in the presence or absence of rebamipide and MNNG. After a 14-day treatment of rebamipide alone, no significant change in number of CD68-expressing cells was detected in either rat strain. However, after concurrent exposure to MNNG for 14days, treatment with rebamipide slightly increased CD68-positive cells in the Lewis strain, and significantly increased them in the Buffalo strain. Analysis of two chemotactic factors of dendritic cells, IL-1β and TNF-α, in the gastric cancer cells showed that expression of IL-1β, but not TNF-α, was induced by rebamipide in a dose-dependent manner. A luciferase promoter assay using gastric SH-10-TC cells demonstrated that an element mediating rebamipide action exists in the IL-1β gene promoter region. In conclusion, rebamipide has potential tumor-suppressive effects on gastric tumorigenesis via the recruitment of dendritic cells, based on the upregulation of the IL-1β gene in gastric epithelial cells.

Histochemical characterization of the mucins of the alimentary tract of the grass snake, Natrix natrix (Colubridae)

Characterization of mucins in the alimentary tract of the grass snake, Natrix natrix was performed by histochemical (PAS, Alcian Blue, pH 2.5 and pH 1.0, sialidase-Alcian Blue, pH 2.5, HID-AB pH 2.5) and lectin-histochemical (WGA, SWGA, PNA, sialidase-PNA, SBA, sialidase-SBA, DBA, sialidase-DBA, ConA, BSI-B4, AAA, UEA-1, LTA) techniques. Oesophageal lining epithelium consisted of ciliated and goblet cells, with no pluricellular glands. Mannosylated sialosulfomucins were observed. Fundic mucosa of stomach presented surface cells producing sialomucins with terminal sialic acid linked to galactose. In gastric glands neck and oxynticopeptic cells were found. Neck cells had sialomucins with mannose, N-acetylglucosamine, galactose, N-acetylgalactosamine and fucose-α-(1,2)-linked residues. Cytoplasm of oxynticopeptic cells showed N-acetylgalactosamine and fucose residues. Secretion of surface cells in pyloric mucosa was similar to that of fundic ones, differing in having fucose. Goblet cells in the small intestine of N. natrix produced sulfo- and sialomucins, with sialic acid linked to galactose and N-acetylgalactosamine residues. Mucins also presented residues of mannose. Goblet cells in the large intestine presented sulfomucins only, with terminal N-acetylgalactosamine, galactose and N-acetylglucosamine. The glycosylation patterns found are probably related to protection against injuries, gastric juice and microorganisms, both pathogenic and decomposers, as well as to dietary adaptations.

Effectiveness of Electroacupuncture at Zusanli (ST36) on the Immunohistochemical Density of Enteroendocrine Cells Related to Gastrointestinal Function

The purpose of this study was to examine the effects of electroacupuncture at Zusanli on the immunohistochemical density of enteroendocrine cells related to gastrointestinal function. The authors investigated the histochemical changes of mucous substances and immunohistochemical density of gastrin, serotonin, calcitonin gene-related peptide (CGRP), insulin, and pancreatic polypeptide (PP) secreting cells in rats. Staining density of mucous substances and the enteroendocrine cells of the gastrointestinal tract was observed with histochemical and immunohistochemical methods. Stainless steel needles with a diameter of 0.25mm were inserted into Zusanli (St36, 5mm below the head of the fibula under the knee joint, and 2mm lateral to the anterior tubercle of the tibia) and connected to an electrical stimulator. The electroacupuncture (EA) stimulation was delivered for 30 minutes at 10mA, 2Hz in EA stimulation (2EA group) or 4Hz in EA stimulation (4EA group) in each experimental group. In 4EA stimulation at the Zusanli, staining density of Alcian blue-periodic acid-Schiff on mucous substances of the stomach body was stronger than those of the 2EA and control groups. Periodic acidi-Schiff staining density of pyloric mucosa in the 4EA group was stronger than that of the 2EA and control groups. The immunohistochemical staining density of gastrin, serotonin, and CGRP-secreting cells of pylorus in the 2EA and 4EA groups was stronger than that of the control group. Immunohistochemical staining density of insulin and PP secreting cells of islets of the pancreas in the 2EA and 4EA groups was stronger than that of the control group. These results suggest that EA stimulus at St36 has the potential to influence gastric mucous substances and enteroendocrine cells (gastrin, serotonin, CGRP, insulin, and PP) that subsequently modulate digestive functions.

Presence and distribution of serotonin in the stomach of the Antarctic silverfish Pleuragramma antarcticum

Serotonin is a signal molecule with a wide range of functions in vertebrates. In Antarctic fishes, the serotonergic system has been studied in the brain, revealing differences from temperate fishes related to the long-term cold adaptation. To date, little is known regarding the peripheral nervous system, and no information is available for the stomach. In the present work, we contribute to fill the gaps by investigating the presence and the immunohistochemical distribution of serotonin in the stomach of the Antarctic silverfish Pleuragramma antarcticum, a cold-adapted key species of the Southern Ocean shelf food web. The main aim was to investigate the serotonergic system at the gastric level, in order to reveal possible peculiarities related to long-term cold adaptation, similar to the ones seen in the central nervous system of Antarctic fishes. Serotonin immunoreactivity was detected in the pyloric and cardiac mucosa of P. antarcticum stomach with immunopositive cells in the pyloric and cardiac surface epithelia and in the tubular glands. No immunopositive fibers and neuronal cell bodies were found. Our results highlight that the serotonin distribution pattern at the gastric level is similar to that described in temperate teleosts. This finding suggests that in P. antarcticum, long-term adaptations to the Antarctic condition do not affect the serotonergic system at the gastric level. In addition, our data constitute the baseline information for further investigations aimed at clarifying the effects of short-term temperature variations on the gastric serotonergic system of Antarctic species in the frame of the global climate change.

Achalasia With Dense Eosinophilic Infiltrate Responds to Steroid Therapy

A patient presented with chronic substernal discomfort and intermittent dysphagia for solids. High-resolution impedance manometry (HRIM) of the esophagus showed that there was no peristalsis in the esophageal body but incomplete relaxation of the lower esophageal sphincter and incomplete bolus transit, so the patient was diagnosed with achalasia. Moreover, probably because of esophageal stasis, eosinophilic infiltration that mimicked a pattern of eosinophilic esophagitis was observed, on the basis of multiple biopsies of the esophagus. The patient was given 50 mg prednisolone once daily; the symptoms improved dramatically, and HRIM showed complete recovery of esophageal peristalsis, deeper relaxation of the lower esophageal sphincter, and complete bolus transit profile. HRIM can therefore be used to assess dysmotility abnormalities in patients with achalasia and eosinophilic-like esophagitis, and steroids relieve these symptoms. Treatment with a high dose of prednisolone resulted in a complete disappearance of dysphagia because of improved esophageal motility and reduced eosinophilic infiltrate. It is therefore important to control the inflammatory process in patients with idiopathic achalasia, which is likely to result from an autoimmune reaction.

Complementary expression of EphB receptors and ephrin-B ligand in the pyloric and duodenal epithelium of adult mice

Eph receptors and ephrin ligands are membrane-bound cell-cell communication molecules that regulate the spatial organisation of cells in various tissues by repulsive or adhesive signals arising from contact between EphB- and ephrin-bearing cells. However, the expression and functions of Eph receptors in the gastric epithelium and Brunner's glands are virtually unknown. We detected several EphB receptors and ephrin-B ligands in the pyloric and duodenal mucosa of the adult mouse by RT-PCR amplification. Immunostaining showed complementary expression patterns, with ephrin-B1 being preferentially expressed in the superficial part and EphB receptors in the deeper part of both epithelia. In the gastric pylorus, ephrin-B1 was expressed in pit cells and proliferating cells of the isthmus. In contrast, EphB2, EphB3, and EphB4 were expressed in pyloric glandular cells and proliferating cells of the isthmus. In the duodenum, ephrin-B1 was expressed in cells lining the ducts of Brunner's glands as well as those covering villi and the upper portion of the crypts of Lieberkühn. In contrast, EphB2 and EphB3 were expressed in the gland segment of Brunner's glands and the lower portion of the crypts and EphB4, in the crypts. In both mucosae, EphB2, EphB3, and EphB4 were found to be tyrosine phosphorylated, suggesting that EphB/ephrin-B signalling might occur preferentially in the isthmus, crypts, and duct-gland transition of Brunner's glands, where the receptor and ligand expression overlaps. Based on these findings, we propose that EphB/ephrin-B signalling may regulate cell positioning within the pyloric and duodenal epithelium.

Distribution, organization and innervation of gastric MALT in conventional piglet

Mucosa-associated lymphoid tissue (MALT) is the initial inductive site for mucosal immunity. It is present in the different layers of the mucosal wall and consists of organized lymphoid tissue which may occur as isolated or aggregated lymphoid follicles (LFs) and interfollicular areas. It is present in many organs, including the pig stomach. Gastric MALT has been intensely studied in experimentally infected pigs but few data are available in healthy, non-gnotobiotic or germ-free animals. In the present study we described the gastric MALT in conventional piglets in the cardiac mucosa of the gastric diverticulum, in the pyloric mucosa, and in the sites of transition from cardiac to oxyntic and from cardiac to pyloric mucosa by means of histological and immunohistochemical stains. The majority of LFs were located in the cardiac mucosa and in the transition from the cardiac to the oxyntic mucosa. Here the LFs were mainly located in the submucosa and reached the mucosa; we called these submucosal lymphoid follicles (SLFs). In the pyloric mucosa and in the transition sites from the cardiac to the pyloric mucosa, LFs were located in the mucosa; we called these mucosal lymphoid follicles (MLFs). In SLFs, a compartmental organization of T and B lymphocytes was present; by contrast, in the MLFs, the T and B cells were intermingled, suggesting the possibility of different roles for the two types of follicles. In the epithelium overlying the lymphoid tissue, numerous T lymphocytes and some cells immunoreactive to cytokeratin-18 were observed. Following the application of the fluorescent tracer DiI into the SLFs of the diverticulum, enteric neurones located in the submucosal plexus were labelled, confirming the interplay between the immune and the enteric nervous system.

Pregnancy-associated glycoprotein, chymosin and pepsinogen immunoreactivity of proteins extracted from fetal gastric tissue in bovine species

The objective of this work was to investigate the expression of gastric aspartic proteinases in fundic and pyloric mucosa removed from bovine fetuses. For this purpose, fractions issued from classical biochemical protocols were analyzed by proteolytic method, by PAG-RIA and by Western blot with the use of antisera raised against both pepsinogens and PAG. A strong reaction of proteins extracted from the fundic mucosa collected at the beginning of pregnancy was revealed with both anti-bPAG-I and anti-bPAG-II antisera, suggesting the expression of pepsinogen F in bovine species. Concerning pyloric mucosa, the analysis by Western blot highlighted a very strong immunoreaction with the anti-bovine chymosin serum. Amino-terminal sequencing allowed to identify bovine fetuin and albumin in fundic extracts, chymosin in the pyloric mucosa extracts, as well as some unknown proteins in both mucosa. Despite no N-terminal microsequence corresponding to the hypothetical pepsinogen F could be identified, it cannot be excluded that an existing bovine pepsinogen F-like molecule could be degraded during the purification procedure or that co-purified proteins could be responsible for masking its N-terminal microsequence.

Aberrant Expression of TFF1, TFF2, and PDX1 and Their Diagnostic Value in Lobular Endocervical Glandular Hyperplasia

Lobular endocervical glandular hyperplasia (LEGH) is a distinct benign glandular lesion expressing gastric gland mucous cell-type mucin (N-acetylglucosaminα1 → 4galactose → R [GlcNAcα1 → 4Gal → R]). To investigate histogenesis and diagnostic markers of LEGH, we examined the immunohistochemical expression profile of gastric surface mucous cell (MUC5AC and TFF1), gastric gland mucous cell (MUC6, TFF2, and GlcNAcα1 → 4Gal → R), gastric pyloric epithelial cell (PDX1), and endocervical cell (keratan sulfate) markers in normal endocervix samples and benign glandular lesions (nabothian cysts, tunnel clusters, and LEGHs). MUC5AC and MUC6 were expressed in normal endocervical mucosa and benign glandular lesions. TFF1, TFF2, GlcNAcα1 → 4Gal → R, and PDX1 were expressed only in LEGH. Keratan sulfate was expressed in normal endocervical mucosa and benign glandular lesions. In LEGH, gastric surface mucous cell and gastric gland mucous cell differentiation were demonstrated, and transdifferentiation from endocervical mucosa into gastric pyloric mucosa was suggested. In addition to GlcNAcα1 → 4Gal → R, TFF1, TFF2, and PDX1 are additional useful markers for LEGH.

NSAID effects on pyloric and duodenal mucosa of dogs

NSAID effects on pyloric and duodenal mucosa of dogs

Effect of nonsteroidal anti-inflammatory drugs with varied cyclooxygenase-2 selectivity on cyclooxygenase protein and prostanoid concentrations in pyloric and duodenal mucosa of dogs

To assess in vivo effects of short-term administration of NSAIDs with varied cyclooxygenase (COX)-2 selectivity on pyloric and duodenal mucosa. 8 healthy dogs. Each dog received deracoxib (2 mg/kg, PO, q 24 h for 3 days), firocoxib (5 mg/kg, PO, q 24 h for 3 days), meloxicam (0.2 mg/kg, PO, q 24 h for 1 day followed by 0.1 mg/kg, PO, q 24 h for 2 days), or placebo orally for 3 days; there was a 4-week interval between successive treatments. Prior to and on day 3 of drug administration, pyloric and duodenal mucosae were assessed endoscopically and biopsy specimens obtained for histologic examination. Cyclooxygenase-1 and -2 protein expressions were assessed (western blotting) and prostanoid concentrations measured (ELISAs). Data were analyzed by use of an ANOVA. Drug administration did not significantly affect endoscopic mucosal scores, histologic scores, or COX-1 or -2 protein expression. The COX-1 protein expression was significantly higher in the pylorus than in the duodenum. Total prostaglandin and thromboxane B(2) (TXB(2)) concentrations were significantly greater in pyloric than in duodenal mucosa. Drug administration had no effect on prostaglandin or TXB(2) concentrations. Prostanoid concentrations in gastric and duodenal tissues, and gross and histologic appearances, were not significantly affected by drugs with varied COX-2 selectivity. These findings suggested that, for these experimental conditions, there were no differences among the preferential and selective COX-2 inhibitors with regard to adverse effects on the gastric and duodenal portions of the gastrointestinal tract of dogs.

Pitavastatin Fails to Lower Serum Lipid Levels or Inhibit Gastric Carcinogenesis in Helicobacter pylori–Infected Rodent Models

Statins are commonly used lipid-lowering drugs that reduce the risk of cardiovascular morbidity and mortality. Although recent studies have pointed to chemopreventive effects of statins against various cancers, their efficacy for gastric cancer is unclear. Here, we examined the effects of pitavastatin, a lipophilic statin, on Helicobacter pylori (H. pylori)-associated stomach carcinogenesis and gastritis using Mongolian gerbil and mouse models. The animals were allocated to H. pylori + N-methyl-N-nitrosourea administration (gerbils, 52 weeks) or H. pylori infection alone groups (gerbils and mice, 12 weeks). After H. pylori infection, they were fed basal diets containing 0 to 10 ppm of pitavastatin. The incidences of H. pylori-associated gastric adenocarcinomas and degrees of chronic gastritis were not decreased by pitavastatin compared with those of control values. Expression of interleukin-1beta and tumor necrosis factor-alpha mRNAs in the pyloric mucosa was markedly up-regulated in pitavastatin-treated animals. Furthermore, in the H. pylori-infected groups, serum total cholesterol, triglyceride, and low-density lipoprotein levels were significantly increased by pitavastatin treatment, contrary to expectation. In the short-term study, H. pylori-infected gerbils and mice also showed significant up-regulation of serum triglyceride levels by pitavastatin, whereas total cholesterol was markedly reduced and low-density lipoprotein exhibited a tendency for decrease in noninfected animals. These findings indicate pitavastatin to be ineffective for suppressing gastritis and chemoprevention of gastric carcinogenesis in H. pylori-infected gerbils. Our serologic results also suggest that the H. pylori infection and consequent severe chronic gastritis interfere with the cholesterol-lowering effects of pitavastatin.

Anti‐inflammatory effects of caffeic acid phenethyl ester (CAPE), a nuclear factor‐κB inhibitor, on Helicobacter pylori‐induced gastritis in Mongolian gerbils

Nuclear factor-kappaB (NF-kappaB) plays a major role in host inflammatory responses and carcinogenesis and as such is an important drug target for adjuvant therapy. In this study, we examined the effect of caffeic acid phenethyl ester (CAPE), an NF-kappaB inhibitor, on Helicobacter pylori (H. pylori)-induced NF-kappaB activation in cell culture and chronic gastritis in Mongolian gerbils. In AGS gastric cancer cells, CAPE significantly inhibited H. pylori-stimulated NF-kappaB activation and mRNA expression of several inflammatory factors in a dose-dependent manner, and prevented degradation of IkappaB-alpha and phosphorylation of p65 subunit. To evaluate the effects of CAPE on H. pylori-induced gastritis, specific pathogen-free male, 6-week-old Mongolian gerbils were intragastrically inoculated with H. pylori, fed diets containing CAPE (0-0.1%) and sacrificed after 12 weeks. Infiltration of neutrophils and mononuclear cells and expression of NF-kappaB p50 subunit and phospho-IkappaB-alpha were significantly suppressed by 0.1% CAPE treatment in the antrum of H. pylori-infected gerbils. Labeling indices for 5'-bromo-2'-deoxyuridine both in the antrum and corpus and lengths of isolated pyloric glands were also markedly reduced at the highest dose, suggesting a preventive effect of CAPE on epithelial proliferation. Furthermore, in the pyloric mucosa, mRNA expression of inflammatory mediators including tumor necrosis factor-alpha, interferon-gamma, interleukin (IL)-2, IL-6, KC (IL-8 homologue), and inducible nitric oxide synthase was significantly reduced. These results suggest that CAPE has inhibitory effects on H. pylori-induced gastritis in Mongolian gerbils through the suppression of NF-kappaB activation, and may thus have potential for prevention and therapy of H. pylori-associated gastric disorders.

Effect of experimental immune atrophic gastritis on the induction of gastric carcinoma by X-irradiation in ICR mice.

Divided doses of 6,000 or 8,000 rad of X-ray were given to the gastric region of ICR/JCL female mice with immune atrophic gastritis produced by the injection with allogenic stomach antigen. The carcinogenic effect of X-rays for inducing gastric carcinoma was significantly increased by this method. Two points can be presented as its reason. First, the pyloric gland mucosa regenerating from injuries by immunization was exposed to the divided dose of X-rays. Second, the marked requirement of gastrin secretion attributable to severe injuries of parietal cell mass by immunization and local X-irradiation acted as a promoting factor on the induction of gastric carcinoma by X-ray for a long time through the trophic effects on the pyloric gland.

Supplemental Sodium Butyrate Stimulates Different Gastric Cells in Weaned Pigs 3

Sodium butyrate (SB) is used as an acidifier in animal feed. We hypothesized that supplemental SB impacts gastric morphology and function, depending on the period of SB provision. The effect of SB on the oxyntic and pyloric mucosa was studied in 4 groups of 8 pigs, each supplemented with SB either during the suckling period (d 4–28 of age), after weaning (d 29 to 39–40 of age) or both, or never. We assessed the number of parietal cells immunostained for H+/K+-ATPase, gastric endocrine cells immunostained for chromogranin A and somatostatin (SST) in the oxyntic mucosa, and gastrin-secreting cells in the pyloric mucosa. Gastric muscularis and mucosa thickness were measured. Expressions of the H+/K+-ATPase and SST type 2 receptor (SSTR2) genes in the oxyntic mucosa and of the gastrin gene in the pyloric mucosa were evaluated by real-time RT-PCR. SB increased the number of parietal cells per gland regardless of the period of administration (P < 0.05). SB addition after, but not before, weaning increased the number of enteroendocrine and SST-positive cells (P < 0.01) and tended to increase gastrin mRNA (P = 0.09). There was an interaction between the 2 periods of SB treatment for the expression of H/K-ATPase and SSTR2 genes (P < 0.05). Butyrate intake after weaning increased gastric mucosa thickness (P < 0.05) but not muscularis. SB used orally at a low dose affected gastric morphology and function, presumably in relationship with its action on mucosal maturation and differentiation.