endothelin-1 and Gastritis

Alcohol consumption increases the risk of gastritis and gastric ulcer. Nutritional alternatives are considered for relieving the progression of gastric mucosal lesions instead of conventional drugs that produce side effects. This study was designed to evaluate the gastroprotective effects and investigate the defensive mechanisms of wheat peptides against ethanol-induced acute gastric mucosal injury in rats. Sixty male Sprague-Dawley rats were divided into six groups and orally treated with wheat peptides (0.1, 0.2, 0.4 g/kgbw) and omeprazole (20 mg/kgbw) for 4 weeks, following absolute ethanol administration for 1 h. Pretreatment with wheat peptides obviously enhanced the vasodilation of gastric mucosal blood vessels via improving the gastric mucosal blood flow and elevating the defensive factors nitric oxide (NO) and prostaglandin E2 (PGE2), and lowering the level of vasoconstrictor factor endothelin (ET)-1. Wheat peptides exhibited anti-inflammatory reaction through decreasing inducible nitric oxide synthase (iNOS) and pro-inflammatory cytokines tumor necrosis factor α (TNF-α), interleukin (IL)-1β, IL-6, and increasing trefoil factor 1 (TFF1) levels. Moreover, wheat peptides significantly down-regulated the expression of phosphorylated nuclear factor kappa-B (p-NF-κB) p65 proteins in the NF-κB signaling pathway. Altogether, wheat peptides protect gastric mucosa from ethanol-induced lesions in rats via improving the gastric microcirculation and inhibiting inflammation mediated by the NF-κB signaling transduction pathway.

Topics: Animals; Anti-Inflammatory Agents; Cytokines; Dinoprostone; Disease Models, Animal; Endothelin-1; Ethanol; Gastric Mucosa; Gastritis; Male; Microcirculation; NF-kappa B; Nitric Oxide; Nitric Oxide Synthase; Omeprazole; Peptides; Protective Agents; Rats; Rats, Sprague-Dawley; Signal Transduction; Trefoil Factors; Triticum; Vasodilation

The study included 60 patients with chronic Halicobacter gastritis (30 with chronic non-atrophic and 30 with atrophic Halicobacter gastritis (CNAHG and CAHG)). The control group was comprised of 15 practically healthy subjects. The aim of the work was to elucidate the role of Helicobacter infection, disturbances of regeneration, endothelin-1 and melatonin-secreting neuroendocrine cells of gastric antrum in progression of chronic Helicobacter gastritis (CHG). It was shown that CHG is due to H. pylori persistence and that patients with CNAHG undergo grade III microbial contamination while in CAHG patients atrophic changes are accompanied by metaplasia of gastric mucosa (GM) and inflammation of different severity. Patients with CNAHG has an increased number of melatonin-positive gastric cells and enhanced apoptotic activity of GM epitheliocytes. Patients with CAHG experience a reduction of melatonin-positive cells correlated with enhanced apoptotic activity of GM epitheliocytes. The number of endothelin-1 positive cells in patients with CNAHG and CAHG was similar to that in controls. Adequate eradication promoted normalization of the number of gastric endothelin-1 and melatonin-secreting neuroendocrine cells in patients with CHG. The apoptotic index reached the control value within 1 month after eradication in CNAHG patients but remained relatively high in CAHG patients.

Topics: Adult; Chronic Disease; Disease Progression; Endothelin-1; Gastritis; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Middle Aged; Pyloric Antrum; Severity of Illness Index

To establish a rat ethanol gastritis model, we evaluated the effects of ethanol on gastric mucosa and studied the preventive effects of geranylgeranylacetone on ethanol-induced chronic gastritis.. One hundred male Sprague-Dawley rats were randomly divided into 4 equal groups: normal control group, undergoing gastric perfusion of normal saline (NS) by gastrogavage; model control group and 2 model therapy groups that underwent gastric perfusion with ethanol (distillate spirits with 56% ethanol content) by gastrogavage for 4 wk. Low or high doses of geranylgeranylacetone were added 1 h before ethanol perfusion in the 2 model therapy groups, while the same amount of NS, instead of geranylgeranylacetone was used in that model control group. The rats were then sacrificed and stomachs were removed. The injury level of the gastric mucosa was observed by light and electron microscopy, and the levels of prostaglandin 2 (PGE₂), endothelin-1 (ET-1) and nitric oxide (NO) were measured by radioimmunoassay and the Griess method.. The gastric mucosal epidermal damage score (EDS; 4.5) and ulcer index (UI; 12.0) of the model control group were significantly higher than that of the normal control group (0 and 0 respectively, all P = 0.000). The gastric mucosal EDS and UI of the 2 model therapy groups (EDS: 2.5 and 2.0; UI: 3.5 and 3.0) were significantly lower than that of the model control group (all P < 0.01). There was no statistically significant difference between the low-dose and high-dose model therapy groups. The expression value of plasma ET-1 of the model control group was higher than that of the normal control group (P < 0.01) and the 2 model therapy groups (all P < 0.01). The expression values of gastric mucosal PGE₂ and serum NO of the model control group were lower than those of the normal control group (all P < 0.05) and the 2 model therapy groups (all P < 0.05). The thickness of the gastric mucous layerand the hexosamine content in the model control group were significantly lower than that in the normal control group (all P < 0.01) and the 2 model therapy groups (all P < 0.05). Scanning and transmission electron microscopy observation showed that in the model control group, the epithelial junctions were vague, the intercellular joints disappeared and damage of the intracellular organelles were significantly worse than those in the normal control group. However, in the 2 model therapy groups, damage to the intercellular joints and organelles was ameliorate relative to the model control group.. Administration of geranylgeranylacetone was correlated with a more favorable pattern of gastric mucosa damage after ethanol perfusion. The mechanism could be related to regulation of ET-1, NO and PGE₂.

Topics: Animals; Anti-Ulcer Agents; Cytoprotection; Dinoprostone; Disease Models, Animal; Diterpenes; Endothelin-1; Ethanol; Gastric Mucosa; Gastritis; Male; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Nitric Oxide; Radioimmunoassay; Rats; Rats, Sprague-Dawley; Stomach Ulcer

Leptin, a multifunctional hormone that regulates food intake and energy expenditure, has emerged recently as an important modulator of gastric mucosal responses to Helicobacter pylori infection. We applied the animal model of H. pylori LPS-induced gastritis to investigate the role of endothelin-1 (ET-1) in the mucosal leptin production. We show that the histologic pattern of inflammation reached a maximum on the fourth day following the LPS and was reflected in a marked increase in the mucosal level of ET-1 and leptin. Therapeutic administration of phosphoramidon, an inhibitor of ECE-1 activity, led to a 61.2% decline in the mucosal ET-1 level and a 64.1% reduction in leptin, while the severity of mucosal inflammatory involvement increased by 28.6%. A drop in the level of leptin and the increase in severity of the inflammatory involvement elicited by the LPS was also attained in the presence of ET(A) receptor antagonist BQ610, but not the ET(B) receptor antagonist BQ788. Moreover, administration of ERK inhibitor, PD98059, in the presence of ET(B) receptor antagonist, but not the ET(A) receptor antagonist, caused reduction in the mucosal leptin level. Our findings are the first to implicate ET-1 as a key factor in up-regulation of gastric mucosal leptin-associated H. pylori infection. We also show that the effect of ET-1 on leptin production is a consequence of ET(A) receptor activation.

Topics: Animals; Aspartic Acid Endopeptidases; Endothelin A Receptor Antagonists; Endothelin B Receptor Antagonists; Endothelin-1; Endothelin-Converting Enzymes; Extracellular Signal-Regulated MAP Kinases; Flavonoids; Gastric Mucosa; Gastritis; Glycopeptides; Helicobacter pylori; Leptin; Lipopolysaccharides; Metalloendopeptidases; Oligopeptides; Piperidines; Rats; Rats, Sprague-Dawley; Receptor, Endothelin A; Receptor, Endothelin B; Up-Regulation

Endothelins have been implicated in gastric mucosal damage in a variety of animal models. Furthermore, clinical reports also show elevated gastric mucosal endothelin-1 levels in patients suffering from peptic ulcer diseases. We have demonstrated, first, the presence of immunoreactive endothelin (IR-ET) in human saliva. We also show that endothelins are rather stable in human saliva. The present study was undertaken to determine whether patients with endoscopically proven upper gastrointestinal diseases have a salivary excess of IR-ET, compared with patients with a normal esophagogastroduodenoscopy. Saliva was collected from fasting subjects prior to esophagogastroduodenoscopy. The levels of IR-ET were measured by the radioimmunoassay method. The salivary concentrations of IR-ET in the studied subjects were as follows: 8.9 +/- 1.0 fmol/mL (mean +/- standard error of the mean) for patients with gastric ulcers (n = 18); 7.3 +/- 1.0 fmol/mL for patients with duodenal ulcers (n = 22); and 6.8 +/- 0.6 fmol/mL for patients with gastritis (n = 28). These values are all higher than that of normal subjects (4.4 +/- 0.5 fmol/mL, n = 20; P < 0.001, P < 0.01, and P < 0.05, respectively). No significant differences in salivary IR-ET were noted between patients with a normal esophagogastroduodenoscopy and patients with esophagitis (3.8 +/- 0.7 fmol/mL, n = 4) or gastric cancer (5.3 +/- 1.4 fmol/mL, n = 4). There were no significant differences in the salivary IR-ET levels between males and females. However, the salivary IR-ET levels in the smokers (8.0 +/- 0.6 fmol/mL, n = 38) were significantly higher (P < 0.01) than those of the non-smokers (6.0 +/- 0.4 fmol/mL, n = 58). There was no correlation of IR-ET levels with age. Our findings suggest that salivary endothelin may have a contributing role in certain gastroduodenal diseases.

Topics: Asian People; Duodenal Ulcer; Endoscopy, Digestive System; Endothelin-1; Endothelin-2; Endothelin-3; Esophagitis; Female; Gastritis; Gastrointestinal Diseases; Humans; Male; Radioimmunoassay; Saliva; Smoking; Stomach Neoplasms; Stomach Ulcer; Taiwan; Up-Regulation; Upper Gastrointestinal Tract

Gastric microcirculatory disturbances are involved in the ethanol-induced gastric mucosal damage. In this study in humans we evaluated the time course of plasma and gastric mucosal endothelin-1 (ET-1) concentrations after intragastric ethanol administration; furthermore we determined the correlation among changes in gastric tissue endothelin-1 and microscopic and gross gastric hemorrhagic damage. ET-1 concentrations in plasma and gastric mucosa were measured by radioimmunoassay. The endoscopic appearance of the gastric mucosa was evaluated and scored on a scale of 0-5, and gastric biopsies for histological evaluation were obtained from the antral and the corpus mucosa just before and 30 min after 40% ethanol administration in seven healthy volunteers. Plasma ET-1 concentration increased as soon as 20 min after ethanol administration, reached a significant peak at 30 min (P < 0.01), and returned to near basal level within 120 min. Gastric mucosal ET-1 concentration significantly increased 30 min after ethanol administration in both the body (P < 0.05) and the antrum (P < 0.05) of the stomach; however the ET-1 increase was significantly higher in the body. Moreover, data obtained 30 min after ethanol administration showed a significant correlation between gastric mucosal ET-1 levels and gross hemorrhagic damage (r = 0.84). A significant correlation was also observed between antral gastric mucosal ET-1 and microscopic lesions (r = 0.70). We conclude that 40% ethanol, given orally, stimulates the release of gastric mucosal endothelin-1 and causes a rapid and time-dependent increase of ET-1 plasma level in humans. The increased plasma and gastric tissue endothelin-1 concentration may play a role in ethanol-induced gastric hemorrhagic injury in humans.

Topics: Adult; Alcohol Drinking; Biopsy; Capillary Permeability; Endothelin-1; Gastric Mucosa; Gastritis; Gastroscopy; Humans; Male; Microcirculation; Peptic Ulcer Hemorrhage; Stomach Ulcer; Vasoconstriction

The animal model of H. pylori lipopolysaccharide (LPS)-induced gastritis was used to study the role of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) in the mucosal release of tumor necrosis factor-alpha (TNF-alpha) and endothelin-1 (ET-1) in response to H. pylori infection. Rats, pretreated with specific inhibitors of p38 and ERK pathways, SB203580 and PD98059, were submitted to intragastric application of H. pylori LPS and maintained on the daily regimen of the inhibitors for 4 days. In the absence of inhibitors, the LPS elicited a pattern of mucosal inflammatory responses resembling that of acute gastritis, and reflected in a massive increase in the mucosal level of ET-1 and TNF-alpha. Administration of SB203580 led to a 63.4% reduction in the extent of inflammatory involvement, the level of ET-1 fell by a 42% and TNF-alpha declined by a 52.3%, whereas PD98059 elicited a 21.2% reduction in the extent of inflammatory involvement and a 22.7% decrease in TNF-alpha, but had no effect on the LPS-induced increase in ET-1. A combination of both inhibitors, while exerting additive effect on TNF-alpha, produced no additional reduction in ET-1 and the extent of inflammatory involvement achieved with SB203580 alone. The findings suggest that the p38 MAPK signaling pathway plays a key role in the mediation of gastric mucosal inflammatory reaction to H. pylori infection.

Topics: Animals; Endothelin-1; Flavonoids; Gastric Mucosa; Gastritis; Helicobacter Infections; Helicobacter pylori; Imidazoles; Lipopolysaccharides; Mitogen-Activated Protein Kinases; p38 Mitogen-Activated Protein Kinases; Pyridines; Rats; Rats, Sprague-Dawley; Signal Transduction; Tumor Necrosis Factor-alpha

Helicobacter pylori is recognized as a primary etiologic factor in the development of gastric disease and the product of particular significance to the virulent action of the bacterium is its cell wall lipopolysaccharide. We applied the animal model of H. pylori lipopolysaccharide-induced acute gastritis to study the effect of antiulcer agents, omeprazole and sucralfate, on the course of mucosal inflammatory responses by analyzing the interplay between the extent of epithelial cell apoptosis and the mucosal expression of endothelin-1 (ET-1), tumor necrosis factor-alpha (TNF-alpha), and the activity of constitutive (cNOS) and inducible (NOS-2) nitric oxide synthase.. Rats pretreated twice daily for 3 consecutive days with omeprazole at 40 mg/kg, sucralfate at 100 mg/kg or the vehicle, were subjected to intragastric application of H. pylori lipopolysaccharide at 50 microg/animal, and after 2, 4, and 10 additional days on the antiulcer drug or vehicle regimen their mucosal tissue used for histologic and biochemical assessment.. In the absence of antiulcer agents, H. pylori lipopolysaccharide elicited within 2 days a pattern of acute mucosal inflammatory responses accompanied by a massive epithelial cell apoptosis, a 2.9-fold increase in the mucosal expression of ET-1, an 11.7-fold enhancement in TNF-alpha, and a 9.3-fold increase in NOS-2, while cNOS activity showed a 5.5-fold decrease. The extent of mucosal inflammatory involvement reached a maximum by the 4th day and showed a decline by the 10th day. This was reflected in a marked reduction in epithelial cell apoptosis, decrease in the mucosal expression of ET-1, TNF-alpha and NOS-2, and the recovery in cNOS activity. Comparing to the vehicle controls, treatment with proton pump inhibitor, omeprazole, led at the end of a 10 day period to a 48.3% reduction in the extent of mucosal inflammatory involvement elicited by H. pylori lipopolysaccharide, while a 74.2% reduction in the mucosal inflammatory involvement was achieved with gastroprotective agent, sucralfate. Moreover, this advantage of sucralfate over omeprazole in countering the lipopolysaccharide-induced changes was reflected at the end of 10 day treatment period in a 20.4% greater decrease in apoptosis, a 47.5% greater reduction in TNF-alpha and a 50.7% greater reduction in ET-1. However, both agents exerted similar influence on the restoration of gastric mucosal cNOS activity and showed a comparable effect at the end of a 10 day treatment in countering the lipopolysaccharide-induced increase in the expression of NOS-2.. The findings suggest that an increase in the mucosal ET-1 level elicited by H. pylori lipopolysaccharide, combined with a decline in cNOS may be responsible for the induction of TNF-alpha and triggering the inflammatory process. We also show that sucralfate exhibits greater efficacy than omeprazole in suppressing the H. pylori-induced mucosal inflammatory responses. This property of sucralfate may well be due to its ability to suppress the mucosal rise in ET-1.

Topics: Acute Disease; Animals; Anti-Ulcer Agents; Apoptosis; Endothelin-1; Gastric Mucosa; Gastritis; Helicobacter pylori; Lipopolysaccharides; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Omeprazole; Rats; Rats, Sprague-Dawley; Sucralfate; Tumor Necrosis Factor-alpha; Up-Regulation

In this study, we investigated gastric mucosal inflammatory responses during Helicobacter pylori lipopolysaccharide-induced gastritis by analyzing the interplay between mucosal expression of endothelin-1 (ET-1), interleukin-4 (IL-4) and tumor necrosis factor-alpha (TNF-alpha). The assays conducted 4 days after intragastric dose of H. pylori lipopolysaccharide demonstrated a pattern of acute mucosal reaction characterized by the inflammatory infiltration of the lamina propria, hyperemia, and epithelial hemorrhage. This was accompanied by a 3.1-fold increase in the mucosal expression of ET-1 and a 9-fold enhancement in TNF-alpha, while the level of IL-4 showed a 20.8% decline. The results implicate ET-1 in gastric mucosal responses to H. pylori, and suggest that an increase in its level, combined with a loss of compensatory action by IL-4, may be responsible for the induction of TNF-alpha and triggering apoptotic events that exacerbate the inflammatory process.

Topics: Animals; Endothelin-1; Gastric Mucosa; Gastritis; Helicobacter pylori; Inflammation Mediators; Interleukin-4; Lipopolysaccharides; Rats; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha