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1.
Exogenously administered zinc compounds have been shown to possess antiulcer activity in the development of gastric lesions. The aim of this study was to investigate the effects of zinc sulphate pretreatment of rats on cysteamine-induced duodenal ulcers and to correlate them with changes in zinc serum and tissue levels. Atomic absorption spectrophotometry was used to determine zinc serum and tissue concentrations in all animal groups. Cysteamine produced marked duodenal ulceration in control animals 24 h after application, with an increase in endogenous zinc tissue concentrations and a marked decrease in serum concentrations. Zinc sulphate (20, 40 or 80 mg kg-1) applied per os one hour prior to cysteamine application inhibited the development of duodenal lesions in a dose-related manner. The application of zinc sulphate in a single intraperitoneal (i.p.) application (80 mg kg-1) did not, however, prevent the formation of duodenal lesions. In order to assess zinc absorption from the gastrointestinal tract, one group of rats received a single oral dose of zinc sulphate (80 mg kg) without cysteamine application. The observations of this study seem to indicate that zinc plays an important cytoprotective role in duodenal ulcer disease.  相似文献   

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3.
We have measured the endogenous levels of gastric and duodenal calcitonin gene-related peptide (CGRP)-, neurokinin A (NKA)-, galanin-vasoactive intestinal polypeptide (VIP)- and neuropeptide Y (NPY)-like immunoreactivity (li) in relation to cysteamine-induced gastric lesions and duodenal ulcers in rats. CGRP-li but not NKA-, galanin-, VIP- or NPY-li was decreased in gastric and duodenal samples following a single ulcerogenic dose of cysteamine (900 mg/kg p.o.). Temporal relationships of this phenomenon showed that CGRP-li was selectively decreased (stomach 45%, duodenum 68% as compared to controls, respectively after 24 h) concomitantly to the formation of acute gastric lesions and duodenal ulcers. Animals bearing healed ulcers 12 days after cysteamine, had gastroduodenal CGRP-li similar to control values. Pretreatment with the selective sensory neurotoxin capsaicin decreased gastroduodenal CGRP-li but not NKA-, galanin-, VIP- or NPY-li, showing that CGRP might be considered a marker of the afferent innervation of the gastroduodenal tract. The residual gastroduodenal CGRP-li levels in capsaicin-pretreated animals were not decreased by cysteamine administration, indicating that the effect of cysteamine is restricted to a peptide pool of primary afferent origin. Duodenal CGRP-li is selectively decreased by the duodenal ulcerogen cysteamine during the acute phase of ulcers formation and might be among the local mediators which afford protection against the ulcerogenic stimuli.  相似文献   

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5.
Growth factors in ulcer healing: lessons from recent studies.   总被引:20,自引:0,他引:20  
Growth factors such as epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF) and more recently vascular endothelial growth factor (VEGF) have been used extensively to heal experimental gastric, duodenal and colonic ulcers in animal models. Encouraging results have been reported in clinical trials with EGF and bFGF. Since our laboratory has been involved with the initial ulcer healing studies with bFGF, PDGF and VEGF, we summarize here the major lessons from these studies and from literature data. These conclusions relate to the role of: 1) gastrointestinal (GI) secretion; 2) epithelial versus vascular components of the healing; 3) efficacy in the upper and lower GI tract; 4) quality of ulcer healing; as well as 5) the endogenous origin; and 6) molar potency of growth factors. Namely, among these growth factors only EGF inhibits gastric acid and stimulates duodenal bicarbonate secretion, while chronic administration of bFGF slightly enhances gastric secretion and PDGF has no effect demonstrating that potent ulcer healing can be achieved without influencing acid base and mucus secretion. This might be related to the fact that these growth factors stimulate with varying potency virtually all the cellular elements needed for ulcer healing, e.g., epithelial cell proliferation and migration by EGF > bFGF > PDGF, fibroblast proliferation by bFGF > PDGF and angiogenesis by VEGF > bFGF > PDGF > EGF. Conceptually, the most interesting results were obtained recently with VEGF which is virtually specific for angiogenesis, illustrating that stimulation of vascular factors is sufficient for ulcer healing because epithelial cells apparently spontaneously proliferate and migrate over a dense granulation tissue to complete the healing process. Since these growth factors directly stimulate the cell components of ulcer healing, it is probably not surprising that they are active in both upper and lower GI tract lesions, produce good quality of ulcer healing in comparison with spontaneously healed duodenal ulcers which are hypovascular and muscle regeneration is not part of natural healing. Contrary to other antiulcer drugs, these growth factors are endogenously derived and play a role in the natural history of ulcer healing, and since these relatively large peptides (18-45 kDa) are active in ng quantities, their molar potency is 2-7 million times superior to cimetidine-like drugs. Thus growth factors are endogenously derived very potent antiulcer drugs which act independently of GI secretion, are active in upper and lower GI lesions, and since they stimulate virtually all the cells of the healing process, they produce an excellent quality of ulcer healing.  相似文献   

6.
The role of endogenous somatostatin in the pathogenesis of duodenal was investigated in the present study by using the cysteamine animal model of the disease. Our previous studies showed a rapid and multiorgan depletion of somatostatin immunoreactivity (SIR) in rats given a single dose of duodenal ulcerogen cysteamine. We now determined whether acetylcholinergic and dopaminergic modulation (both known to influence the development of duodenal ulcer) are accompanied by modification of cysteamine-induced SIR depletion in rat organs. Vagotomy performed either 1 or 18 h before cysteamine administration did not interfere with the chemically induced SIR decrease in pancreas, gastric and duodenal mucosa. Vagal denervation alone had no marked influence on SIR levels but if combined with cysteamine, the SIR depletion in the stomach was significantly more pronounced than after the duodenal ulcerogen alone. Pretreatment with the dopamine agonists bromocriptine or lergotrile (known to prevent the chemically induced duodenal ulcers) did not influence the SIR depletion by cysteamine. Thus cysteamine depletes endogenous somatostatin in peripheral organs (e.g., stomach, duodenum, pancreas) by mechanisms independent of both vagus nerve and dopamine agonists. A role of central somatostatin depletion leading to disinhibition of vagus is also considered in the pathogenesis of experimental duodenal ulcer.  相似文献   

7.
F Drago  C Montoneri  C Varga  F Làszlò 《Life sciences》1999,64(25):2341-2350
Since the sexual dimorphism of gastroduodenal ulcers is well known and might possibly relate to the actions of sex hormones, we studied the role of the female sex steroids, progesterone and 17beta-estradiol in cysteamine-induced mucosal ulcers in female Wistar rats (200-220 g). Administration of cysteamine (400 mg/kg, s.c.) provoked macroscopic gastroduodenal mucosa injury as assessed planimetrically, an increase in microvascular permeability in the stomach and the duodenum as assessed by extravasation of radiolabelled albumin, and decreased gastroduodenal mucus levels as assessed by the Alcian blue technique. Ovariectomy (2 weeks before cysteamine) decreased plasma 17beta-estradiol level as assessed by radioimmunoassay, gastroduodenal macroscopic injury and albumin extravasation, and increased mucus levels following cysteamine challenge. Administration of progesterone (10-50 mg/kg/week, s.c.) attenuated in a dose-dependent manner cysteamine-induced gastroduodenal mucosa injury and microvascular leakage, while it increased mucus levels in the stomach and the duodenum. In contrast, administration of 17beta-estradiol (1-5 mg/kg/week, s.c.) dose-dependently augmented gastric and duodenal macroscopic mucosa lesions and microvascular injury provoked by cysteamine, and caused a further reduction in gastroduodenal mucus levels observed after cysteamine administration. In different experiments, ovariectomy decreased indomethacin-induced gastroduodenal injury. The injection of 17beta-estradiol (1-5 mg/kg/week) did not affect gastroduodenal damage, while treatment with progesterone (10-50 mg/kg/week) protected against indomethacin-provoked mucosa ulcers. It is concluded that female sex steroids play a role in drug-induced gastroduodenal ulcers by modulating microvascular permeability and mucus secretion.  相似文献   

8.
Melatonin (MT) and its precursor L-tryptophan (TRP) are implicated in the protection of gastric mucosa against aspirin-induced lesions and in the acceleration of healing of idiopathic gastro-duodenal ulcers, but no information is available whether these agents are also effective in healing of gastroduodenal ulcers accompanied by Helicobacter pylori (H. pylori) infection. In this study three groups A, B and C, each including 7 H. pylori-positive patients with gastric ulcers and 7 H. pylori-positive patients with duodenal ulcers, aging 28-50 years, were randomly assigned for the treatment with omeprazole 20 mg twice daily combined with placebo (group A), MT administered in a dose of 5 mg twice daily (group B) or TRP applied in a dose of 250 mg twice daily (group C). All patients underwent routine endoscopy at day 0 during which the gastric mucosa was evaluated and gastric biopsies were taken for the presence of H. pylori and histopathological evaluation. The rate of ulcer healing was determined by gastroduodenoscopy at day 0, 7, 14 and 21 after the initiation of the therapy. Plasma MT, gastrin, ghrelin and leptin were measured by specific RIA. At day 21, all ulcers were healed in patients of groups B and C but only 3 out of 7 in group A of gastric ulcers and 3 out of 7 in duodenal ulcers. Initial plasma MT showed similar low levels in all three groups but it increased several folds above initial values in ulcer patients at day 7, 14 and 21. Plasma gastrin and leptin levels showed a significant rise over initial values in patients treated with omeprazole and placebo, MT or TRP while plasma ghrelin levels were not significantly affected by these treatments. We conclude that MT or TRP added to omeprazole treatment, significantly accelerates healing rate of H. pylori infected chronic gastroduodenal ulcers over that obtained with omeprazole alone and this likely depends upon the significant rise in plasma MT and possibly also in leptin levels, both hormones involved in the mechanism of gastroprotection and ulcer healing.  相似文献   

9.
Backgroundp-Cymene and rosmarinic acid are secondary metabolites found in several medicinal plants and spices. Previous studies have demonstrated their anti-inflammatory, antioxidant, and cytoprotective effects.PurposeTo evaluate their gastroduodenal antiulcer activity, gastric healing and toxicity in experimental models.MethodsPreventive antiulcer effects were assessed using oral pre-treatment on HCl/ethanol-induced gastric lesions and cysteamine-induced duodenal lesions models. Gastric healing, the underlining mechanisms and toxicity after repeated doses were carried out using the acetic acid-induced gastric ulcer rat model and oral treatment for 14 days.ResultsIn the HCl/ethanol-induced gastric ulcer and cysteamine-induced duodenal injury, p-cymene and rosmarinic acid (50–200 mg/kg) decreased significantly the ulcer area, and so prevented lesions formation. In the acetic acid-induced ulcer model, both compounds (200 mg/kg) markedly reduced the ulcerative injury. These effects were related to an increase in the levels of reduced glutathione (GSH) and interleukin (IL)-10, and due to a decrease in malondialdehyde (MDA), IL-1β, tumor necrosis factor (TNF)-α, total and mitochondrial reactive oxygen species (ROS) levels. Downregulation of factor nuclear kappa B (NFκB) and enhanced expression of suppressor of cytokine signaling (SOCS)3 were also demonstrated. Furthermore, positive vascular endothelial growth factor (VEGF), metalloproteinase (MMP)-2, and cyclooxygenase (COX-2)-stained cells were increased in treated groups. Treatment also upregulated the platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), transforming growth factor (TGF)-β and epidermal growth factor receptor (EGFR) in gastric tissues. In isolated gastric epithelial cells this healing effect seems to be linked to a modulation of apoptosis, proliferation, survival and protein phosphorylation, such as the extracellular signal-regulated kinases (ERK)1/2 and p38 mitogen-activated protein kinase (MAPK). Oral toxicity investigation for 14 days revealed no alterations in heart, liver, spleen, and kidneys weight nor the biochemical and hematological assessed parameters. p-Cymene and rosmarinic acid also protected animals from body weight loss maintaining feed and water intake.ConclusionsData altogether suggest low toxicity, antiulcer and gastric healing activities of p-cymene and rosmarinic acid. Antioxidant and immunomodulatory properties seem to be involved in the curative effect as well as the induction of different factors linked to tissue repair.  相似文献   

10.
A study was made of the effects of some endogenous opioids (beta-endorphin, gamma-endorphin, met-enkephalin, leu-enkephalin and dinorphin) formed in the body from different high-molecular precursors (pro-opiomelanocortin, proenkephalins A and B) on the development in rats of the cysteamine-induced duodenal ulcers. All the peptides under study, gamma-endorphin, in particular, had an anti-ulcerous activity which was mediated by specific opiate receptors. The majority of the opioids was characterized by reduction of the anti-ulcerous effect as the dose was raised. It is assumed that protection of the duodenal mucosa under ulcerogenic exposures is an essential property of endogenous peptides. It is concluded that opioid peptides derived from different precursors are arranged in a complex synergic system responsible for cytoprotection of the duodenum.  相似文献   

11.
An attempt of the assessment of T-cells function in patients with gastric or duodenal ulcer has been undertaken. The studies involved 60 patients with gastric or duodenal ulcers and 47 individuals of the control group. Lymphocyte reactivity to different concentrations of concanavalin A and phytohemagglutinin has been assessed with leukocyte migration inhibition test. Lymphocyte T function has been examined also in patients with gastric or duodenal ulcers in reference to the theophylline-dependent and theophylline-sensitive subpopulation of T-cells. Leukocyte migration index values after phytohemagglutinin and concanavalin A did not differ significantly in patients with gastric or duodenal ulcers and theophylline-sensitive T-cells. Differences have been noted in the migration inhibition deficits. This phenomenon has been least frequent in case of phytohemagglutinin in the control group (5.8%) and most frequent in patients with gastric ulcer (62%). Percentage of patients responding to higher concanavalin A concentration (40 micrograms/ml) with leukocyte migration inhibition has been the highest in patients with duodenal ulcer. This index value has been significantly lower (p < 0.05) only in patients with duodenal ulcer and increased number of theophylline-dependent lymphocytes T. Increased reactivity of T-cells to higher concanavalin A concentration in patients with duodenal ulcer with theophylline-dependent T-cells in peripheral blood probably indicates increased the suppressor lymphocytes activity.  相似文献   

12.
The effect of oxytocin (1 mg/kg s.c) on gastric acid secretion and on different experimentally induced gastric and duodenal ulcers was studied. The acute gastric ulcer models used were pylorus ligation, indomethacin, ethanol and histamine induced acute gastric ulcers. Chronic gastric ulcers were induced using acetic acid and duodenal ulcers by cysteamine hydrochloride. Oxytocin showed significant antisecretory and antiulcer activity in pylorus ligated rats. Similarly oxytocin reduced the ulcer index in histamine induced gastric ulcers in guinea pigs and cysteamine induced duodenal ulcers in rats. The antiulcer and antisecretory effect was comparable to that of ranitidine (50mg/kg, i.p) though less in intensity. However, it did not show any gastric cytoprotective effect in ethanol and indomethacin induced ulcer models but ranitidine showed protection (p<0.05) in later model. Oxytocin enhanced gastric ulcer healing in acetic acid induced chronic gastric ulcer model. The reversal of oxytocin effect by atosiban, an oxytocin receptor antagonist indicates a role for oxytocin receptors. The antiulcer activity of oxytocin can be attributed to its antisecretory effect.  相似文献   

13.
Angiogenesis is an important event for gastric ulcer healing. Vascular endothelial growth factor (VEGF) is known to be a potent stimulator of angiogenesis. This study consequently examined VEGF production, VEGF mRNA expression and angiogenesis during the spontaneous and indomethacin-delayed healing of acetic acid-induced ulcers in rats. The production of VEGF, taking place in the normal mucosa, was significantly elevated by ulceration. The mRNA expression of three isoforms of VEGF (VEGF188, VEGF164 and VEGF120) was also detected. Following the increase in VEGF production, angiogenesis was significantly promoted in the ulcer base. VEGF-immunoreactivity was observed in granulocytes, fibroblasts and regenerated epithelial cells. Indomethacin markedly inhibited prostaglandin E2 synthesis in the ulcer base, resulting in the prevention of ulcer healing. Angiogenesis was also significantly inhibited by indomethacin, but neither VEGF production nor VEGF mRNA expression was reduced. Such results suggest that VEGF might play a role in angiogenesis in the spontaneous healing of gastric ulcers in rats. However, the inhibition of angiogenesis in indomethacin-delayed ulcer healing is not explainable on VEGF expression.  相似文献   

14.
Copper is known as Gunma Kaalan in Siddha literature, which means that the drug is effective for healing ulcers. The herbomineral drug “Thamira parpam” is prepared by calcining the purified copper foils with rock salt, lime juice, bracteated birth wort juice, and Alangium root decoction according to Siddha medicine. Our study investigated the possible role of Thamira parpam (TP) in the management of cysteamine-induced duodenal ulcers. Cysteamine (400 mg kg?1?body weight?1, two doses at 4 h interval) orally given to rats resulted in high ulcer index, increased TBARS with concomitant depletion of antioxidants such as superoxide dismutase, glutathione, glutathione peroxidase, and inflammatory markers cathepsin D, and myeloperoxidase (p?<?0.01). Herbomineral drug TP (0.5, 1, and 2 mg/kg, p.o.) challenged with cysteamine attenuated the elevation of TBARS and imbalance of antioxidants. In the increases in liver inflammatory markers, tissue histopathology changes were not severe in TP treatment. Positive control omeprazole (25 mg/kg, body weight, orally) showed considerable protection against anomaly in biochemical parameters and tissue histology. Hence, our results indicate that the attenuation of oxidative stress by the herbomineral drug in experimentally induced damage to liver and duodenum of rats could be mediated by free radical quenching property.  相似文献   

15.
Thirteen patients with peptic ulcer were treated with fresh cabbage juice, which, experiments have indicated, contains an antipeptic ulcer factor. This factor (vitamin U) prevents the development of histamin-induced peptic ulcers in guinea pigs.The average crater healing time for seven of these patients who had duodenal ulcer was only 10.4 days, while the average time as reported in the literature, in 62 patients treated by standard therapy, was 37 days.The average crater healing time for six patients with gastric ulcer treated with cabbage juice was only 7.3 days, compared with 42 days, as reported in the literature, for six patients treated by standard therapy.The rapid healing of peptic ulcers observed radiologically and gastroscopically in 13 patients treated with fresh cabbage juice indicates that the anti-peptic ulcer dietary factor may play an important role in the genesis of peptic ulcer in man.  相似文献   

16.
Buruli Ulcer (BU) is a necrotizing skin disease caused by Mycobacterium ulcerans infection. BU is characterized by a wide range of clinical forms, including non-ulcerative cutaneous lesions that can evolve into severe ulcers if left untreated. Nevertheless, spontaneous healing has been reported to occur, although knowledge on this process is scarce both in naturally infected humans and experimental models of infection. Animal models are useful since they mimic different spectrums of human BU disease and have the potential to elucidate the pathogenic/protective pathway(s) involved in disease/healing. In this time-lapsed study, we characterized the guinea pig, an animal model of resistance to M. ulcerans, focusing on the macroscopic, microbiological and histological evolution throughout the entire experimental infectious process. Subcutaneous infection of guinea pigs with a virulent strain of M. ulcerans led to early localized swelling, which evolved into small well defined ulcers. These macroscopic observations correlated with the presence of necrosis, acute inflammatory infiltrate and an abundant bacterial load. By the end of the infectious process when ulcerative lesions healed, M. ulcerans viability decreased and the subcutaneous tissue organization returned to its normal state after a process of continuous healing characterized by tissue granulation and reepethelialization. In conclusion, we show that the experimental M. ulcerans infection of the guinea pig mimics the process of spontaneous healing described in BU patients, displaying the potential to uncover correlates of protection against BU, which can ultimately contribute to the development of new prophylactic and therapeutic strategies.  相似文献   

17.
The incidence of ulcer perforation in 1480 patients treated in the Bergen area of Norway between 1935 and 1990 was analyzed for daily (circa-dian), weekly (circaseptan), and yearly (circannual) time effects. A circadian rhythm was found overall that was reproducible and fairly stable across seasons, decades, and days of the week. After subgrouping, a circadian rhythm was found in younger patients, males, and duodenal perforations, while a 12h (circasemidian) rhythm characterized ulcer perforation for women and for gastric ulcers. Duodenal perforations showed highest incidence in the afternoon, while gastric perforations showed a major peak around noon and a secondary peak near midnight. For duodenal ulcer perforation, the circannual pattern was characterized by a 6-month rhythm, with significantly higher incidence in May-June-July and in November-December in most subgroups. A circaseptan rhythm was not found, but there was a significantly higher incidence on Thursday-Friday as compared to Sunday-Monday. The pathophysiological mechanisms underlying the perforation of an ulcer thus seemed to show pronounced circadian and 6-month rhythmic variations, much less so circaseptan or circannual rhythms. While it is likely that exogenous environmental and/or societal factors play a significant role, variations in ulcer perforation may be related to endogenous biological rhythms in pathophysiological factors since the circadian pattern of duodenal perforations follows that for gastric acidity. Knowledge of the temporal patterns in peptic ulcer perforation and associated pathophysiologic factors should prove useful in optimizing the chronotherapeutic management of ulcer disease.  相似文献   

18.
Circulating gastric-mucosa antibodies were found more frequently among patients with different forms of chronic gastritis than among a miscellaneous control group and groups that presented prepyloric ulcer or duodenal ulcer. A higher incidence of circulating antibodies and of chronic gastritis lesions among Caucasians and “Mestizos” than among Negroes was also observed. The latter showed a higher tendency to duodenal ulcer and prepyloric ulcer. The high incidence of gastritis and gastric ulcer of the Chinese and the Mestizos support the ethnic relation between these two human groups. Our study favors the hypothesis that genetic and ethnic factors influence, on the one hand, chronic gastritis and gastric ulcer and, on the other hand, duodenal and prepyloric ulcers.  相似文献   

19.
The gastric cytoprotective effects of vitamin A, De-Nol and sucralfate were compared with the effectiveness of pirenzepine in healing ulcer in patients with chronic gastric ulcer. A total of 100 patients was randomized into different groups: the patients were treated with antacids, vitamin A (3 X 50.000 IU), De-Nol liquid (4 X 5 ml), sucralfate (4 X 1 g) or pirenzepine (3 X 50 mg). The treatment was continued for 4 weeks. At the beginning, 2 and 4 weeks after starting treatment the patients were subjected to endoscopy and the size of the ulcer was measured planimetrically. The ulcer-healing effect of De-Nol liquid was significantly better than that of the antacids (p less than 0.01). Ulcer size was reduced significantly in all groups (p less than 0.01), however, at the end of the study the gastric ulcers were smallest in the De-Nol treated group (p less than 0.001). The dynamics of ulcer healing in the second week was most favourable in the patients receiving vitamin A (p less than 0.01). The present data point to the cytoprotective effects of De-Nol liquid, vitamin A and sucralfate and to their ability of healing chronic gastric ulcers.  相似文献   

20.
The present study examined the expression of 73-kDa of heat shock cognate protein (HSC70), 72-kDa of heat shock protein (HSP70) and 47-kDa of HSP (HSP47) observed in the ulcer healing process in rats. Gastric ulcers were induced by a luminal application of acetic acid in male Donryu rats. During the ulcer healing process, the expression of HSPs in the ulcerated tissue was determined. A high level of HSC70 expression was observed both in the normal mucosa and ulcerated tissue, but the level did not change upon ulceration and ulcer healing. While HSP70 and HSP47 were markedly expressed in the ulcer base during ulceration, and decreased with ulcer healing. HSP70 expression in the ulcer margin was gradually increased with ulcer healing. Omeprazole accelerated the healing of gastric ulcers with strong inhibition of gastric acid secretion, while indomethactin delayed in ulcer healing despite slight inhibition of gastric acid secretion. Omperazole enhanced the expression of HSP70 both in the ulcer margin and base, but it reduced HSP47 expression in the ulcer base Indomethacin markedly enhanced HSP47 expression only in the ulcer base. In conclusion, the expression of HSP70 and HSP47 is changed during ulcer healing. Furthermore, it was suggested that the enhanced expression of HSP70 is involved in acceleration of ulcer healing, but overexpression of HSP47 is involved in delayed ulcer healing.  相似文献   

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