Indomethacin-induced Gastric Injury In Rats Research Articles

RETRACTED: Alhakamy et al. Optimized Ellagic Acid-Ca Pectinate Floating Beads for Gastroprotection against Indomethacin-Induced Gastric Injury in Rats. Biomolecules 2020, 10, 1006.

The journal retracts the article, "Optimized Ellagic Acid-Ca Pectinate Floating Beads for Gastroprotection against Indomethacin-Induced Gastric Injury in Rats" [...].

LC-MS-Based Metabolomics Reveals the Mechanism of Protection of Berberine against Indomethacin-Induced Gastric Injury in Rats.

Berberine is a natural isoquinoline alkaloid with low toxicity, which exists in a wide variety of medicinal plants. Berberine has been demonstrated to exhibit potent prevention of indomethacin-induced gastric injury (GI) but the related mechanism remains unclear. In the present study, liquid chromatography-mass spectrometry (LC-MS)-based metabolomics was applied for the first time to investigate the alteration of serum metabolites in the protection of berberine against indomethacin-induced gastric injury in rats. Subsequently, bioinformatics was utilized to analyze the potential metabolic pathway of the anti-GI effect of berberine. The pharmacodynamic data indicated that berberine could ameliorate gastric pathological damage, inhibit the level of proinflammatory factors in serum, and increase the level of antioxidant factors in serum. The LC-MS-based metabolomics analysis conducted in this study demonstrated the presence of 57 differential metabolites in the serum of rats with induced GI caused by indomethacin, which was associated with 29 metabolic pathways. Moreover, the study revealed that berberine showed a significant impact on the differential metabolites, with 45 differential metabolites being reported between the model group and the group treated with berberine. The differential metabolites were associated with 24 metabolic pathways, and berberine administration regulated 14 of the 57 differential metabolites, affecting 14 of the 29 metabolic pathways. The primary metabolic pathways affected were glutathione metabolism and arachidonic acid metabolism. Based on the results, it can be concluded that berberine has a gastroprotective effect on the GI. This study is particularly significant since it is the first to elucidate the mechanism of berberine's action on GI. The results suggest that berberine's action may be related to energy metabolism, oxidative stress, and inflammation regulation. These findings may pave the way for the development of new therapeutic interventions for the prevention and management of NSAID-induced GI disorders.

RETRACTED: Ahmed et al. Omega-3 Self-Nanoemulsion Role in Gastroprotection against Indomethacin-Induced Gastric Injury in Rats. Pharmaceutics 2020, 12, 140.

The journal retracts the article, "Omega-3 Self-Nanoemulsion Role in Gastroprotection against Indomethacin-Induced Gastric Injury in Rats" [...].

Gastroprotective effects and metabolomic profiling of Chasteberry fruits against indomethacin-induced gastric injury in rats

Vitex agnus castus L. extract (VACE) was investigated for its gastroprotective properties and possible molecular mechanisms in rats. VACE (60 or 120 mg/kg) or Esomeprazole (20 mg/kg) were orally administered for 3 weeks before the induction of gastropathy using indomethacin (30 mg/kg, single oral dose). VACE ameliorated the indomethacin-induced gastric juice acidity and pathological changes. VACE significantly preserved GSH, SOD, NO and PGE2 contents, while decreased lipid-peroxide, TNF-α and MPO contents. Moreover, VACE downregulated NF-κB1, COX-2, Caspase-3 and upregulated Bcl-2 and HSP-70 expression. Ultra-high-performance liquid chromatography (UPLC) coupled with quadrupole high-resolution time of flight mass spectrometry (qTOF-MS) enabled the tentative identification of 87 compounds allocated in seven main classes including flavonoids, glycosylated iridoid and labdane diterpenes. Notably, different agnuside derivatives and diterpenoids were reported in VACE for the first time. In conclusion, VACE contains an arsenal of bioactive metabolites which may exhibit gastroprotection by inhibiting inflammation, oxidative stress, and apoptosis.

Protective effects of perindopril against indomethacin-induced gastric mucosal damage through modulation of DDAH-1/ADMA and ACE-2/ANG-(1-7) signaling pathways

Indomethacin is a widely used nonsteroidal anti-inflammatory drug; however, its clinical utility is accompanied by serious adverse reactions including peptic ulcers. The current study aims to investigate the protective potential of perindopril against indomethacin-induced gastric injury in rats. Perindopril (4 mg/kg) was administered orally for 7 days and indomethacin (60 mg/kg, single oral dose) was administered on the 7th day, 1 h after perindopril administration. Pantoprazole was used as a standard agent. Ulcer index (UI), preventive index ratio (PI), histopathological examination, oxidative stress, and inflammatory biomarkers were investigated. Perindopril significantly decreased UI while increased PI and counteracted histopathological aberrations induced by indomethacin. It alleviated indomethacin-induced oxidative stress by lowering NO while increasing GSH content and superoxide dismutase activity. Perindopril significantly downregulated TNF-α and asymmetric dimethylarginine (ADMA), while significantly upregulated COX-2, PGE-2, dimethylarginine dimethylaminohydrolase-1 (DDAH-1), ANG-(1-7), and ACE-2 expression. Together, these findings suggest the gastroprotective effects of perindopril through modulation of DDAH-1/ADMA and ACE-2/ANG-(1-7) signaling. HIGHLIGHTS Perindopril attenuated gastric histopathological damage. It increased GSH content and SOD activity while decreased NO content. It modulated gastric ADMA and DDAH-1 activity. It reduced TNF-α, while increased COX-2 and PGE-2 expression. It upregulated ACE-2 activity and ANG-(1-7) protein expression.

Benzyl isothiocyanates modulate inflammation, oxidative stress, and apoptosis via Nrf2/HO-1 and NF-κB signaling pathways on indomethacin-induced gastric injury in rats.

The present study investigated the gastroprotective activity of benzyl isothiocyanates (BITC) on indomethacin (IND)-induced gastric injury in a rat model and explicated the possible involved biochemical, cellular, and molecular mechanisms. The rat model with gastric ulcers was established by a single oral dose of IND (30 mg per kg b.wt). BITC (0.75 and 1.5 mg kg-1) and esomeprazole (20 mg per kg b.wt) were orally administered for 3 weeks to rats before the induction of gastric injury. Compared with the IND group, BITC could diminish both the macroscopic and microscopic pathological morphology of gastric mucosa. BITC significantly preserved the antioxidants (glutathione GSH, superoxide dismutase SOD), nitric oxide (NO), and prostaglandin E2 (PGE2) contents, while decreasing the gastric mucosal malondialdehyde (MDA), tumor necrosis factor alpha (TNFα), and myeloperoxidase (MPO) contents. Moreover, BITC remarkably upregulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), hemoxygenase-1 (HO-1), and NAD(P)H : quinone oxidoreductase (NQO1). In addition, BITC activates the expression of heat shock protein 70 (HSP-70) and downregulated the expression of nuclear factor-κB (NF-κB) and caspase-3 to promote gastric mucosal cell survival. To the best of our knowledge, this study is the first published report to implicate the suppression of inflammation, oxidative stress, and Nrf2 signaling pathway as a potential mechanism for the gastroprotective activity of BITC.

Effect of Single and Repeated Administration of Amitriptyline on Experimental Gastric Ulcer

Amitriptyline is an antidepressant drug widely used as analgesic in the management of chronic pain syndromes. It is also attracting the attention of researchers as an alternative agent for peptic ulcer management because studies have shown that most patients with peptic ulcer also suffer from depression. Thus, this study was conducted to investigate gastroprotective effects of single and repeated dose administration of amitriptyline against indomethacin-induced gastric injury in rats. Rats were randomly divided into three groups of eight rats/each. For 14 days, Group I (control) and Group II (single dose) received distilled water; Group III (repeated dose) received 10 mg/kg amitriptyline orally once daily. On day 15, Group I was given distilled water; Group II and III were given 10 mg/kg amitriptyline orally. Thirty minutes later, indomethacin (25 mg/kg) was administrated orally to all the groups. Six hours after indomethacin administration, animals were sacrificed under thiopental sodium anaesthesia, stomachs were rapidly removed, cut along the greater curvature and cleaned. The stomachs were macroscopically evaluated; total area of stomach and visible ulcerated areas were measured using millimeter square paper. Finally, the stomachs were fixed in 10% formalin for histopathologic valuation. Single dose administration of amitriptyline significantly reduced ulcer indexes and gastric erosions as compared to the control group.However, its role against inflammatory reactions such as necrosis, polymorphonuclear leucocyte infiltration, neutrophil and eosinophil reactions were statistically insignificant. On the other hand, repeated dose administration of amitriptilyine produced significant gastroprotective effects as observed from macroscopical and histopathological evaluation results. Moreover, there was also a significant difference in the gastroprotective effects between single and repeated dose of amitriptyline against indomethacin-induced gastric damage. In conclusion, the results of this study evealed that repeated dose administration of amitriptyline showed better gastroprotective effects compared to single dose amitriptyline administration and the control group.
 Keywords: amitriptyline, gastroprotective effects, indomethacin, histopathologic evaluation, rats

Optimized Ellagic Acid-Ca Pectinate Floating Beads for Gastroprotection against Indomethacin-Induced Gastric Injury in Rats.

A peptic ulcer is an alimentary tract injury that leads to a mucosal defect reaching the submucosa. This work aimed to optimize and maximize ellagic acid (EA) loading in Ca pectinate floating beads to maximize the release for 24 h. Three factors were selected: Ca pectinate concentration (X1, 1–3 w/v %), EA concentration (X2, 1–3 w/v %) and the dropping time (X3, 10–30 min). The factorial design proposed eight formulations. The optimized EA–Ca pectinate formulation was evaluated for the gastric ulcer index and the oxidative stress parameter determination of gastric mucosa. The results indicated that the optimum EA–Ca pectinate formula significantly improved the gastric ulcer index in comparison with raw EA. The protective effect of the optimized EA–Ca pectinate formula was further indicated by the histopathological features of the stomach. The results of the study indicate that an EA formulation in the form of Ca pectinate beads would be effective for protection against gastric ulcers because of Nonsteroidal anti-inflammatory drugs (NSAID) administration.

Omega-3 Self-Nanoemulsion Role in Gastroprotection against Indomethacin-Induced Gastric Injury in Rats.

Peptic ulcer disease is an injury of the alimentary tract that leads to a mucosal defect reaching the submucosa. This study aimed to formulate and optimize omega-3 oil as a self-nanoemulsifying drug delivery system (SNEDDS) to achieve oil dispersion in the nano-range in the stomach to augment omega-3 oil gastric ulcer protection efficacy. Three SNEDDS components were selected as the design factors: the concentrations of the oil omega-3 (X1, 10–30%), the surfactant tween 20 and Kolliphor mixture (X2, 20–40%), and the cosurfactant transcutol (X3, 40–60%). The mixture experimental design proposed twenty-three formulations with varying omega-3 SNEDDS formulation component percentages. The optimized omega-3 SNEDDS formula was investigated for gastric ulcer protective effects by evaluating the ulcer index and by the determination of gastric mucosa oxidative stress parameters. Results revealed that optimized omega-3-SNEDDS achieved significant improvement in the gastric ulcer index in comparison with pure omega-3 oil. Histopathological findings confirmed the protective effect of the formulated optimized omega-3 SNEDDS in comparison with omega-3 oil. These findings suggest that formulation of omega-3 in the form of a SNEDDS would be more effective in gastric ulcer protection than the administration of omega-3 as a crude oil.

The gastroprotective effect of N-acetylcysteine and genistein in indomethacin-induced gastric injury in rats.

The protective effect of N-acetylcysteine (NAC) and genistein (GEN) on an experimental model of indomethacin (IND)-induced gastric injury was investigated. A total of 50 male rats were divided into 5 groups: (1) control, (2) IND, (3) NAC pretreated, (4) GEN pretreated, and (5) NAC+GEN pretreated. Rats in groups 3-5 were orally administered NAC (500 mg/kg), GEN (10 mg/kg), or both, respectively, once daily for 7 days before the induction of gastric injury by IND (50 mg/kg). The stomach was removed for biochemical analysis and histopathological examination. Pretreatment with NAC, GEN, or both significantly improved ulcer indices and increased nitric oxide level and superoxide dismutase activity. They also significantly decreased malondialdehyde, tumour necrosis factor α levels, and myeloperoxidase activity, and downregulated matrix metalloproteinase 9 (MMP-9) gene expression compared to the IND group. NAC alone ameliorated IND-induced apoptosis, whereas GEN only significantly increased prostaglandin E2 level. Further, coadministration of both resulted in a significantly better gastroprotective effect versus solo administration. Coadministration of NAC and GEN has an additive gastroprotective effect in IND-induced gastric injury, which may be through interaction of their potential cytoprotective, antioxidant, anti-inflammatory, and antiapoptotic mechanisms together with regulation of MMP-9 expression.

A Novel Role of Irbesartan in Gastroprotection against Indomethacin-Induced Gastric Injury in Rats: Targeting DDAH/ADMA and EGFR/ERK Signaling

The advent of angiotensin II type 1 receptor blockers (ARBs) as intriguing gastroprotective candidates and the superior pharmacokinetics and pharmacodynamics displayed by irbesartan compared to many other ARBs raised the interest to investigate its gastroprotective potential in a rat model of gastric injury. Irbesartan (50 mg/Kg) was orally administered to male Wistar rats once daily for 14 days; thereafter gastric injury was induced by indomethacin (60 mg/Kg, p.o). Irbesartan reduced gastric ulcer index, gastric acidity, and ameliorated indomethacin-induced gastric mucosal apoptotic and inflammatory aberrations, as demonstrated by hampering caspase-3, prostaglandin E2 and tumor necrosis factor-alpha levels and cyclooxygenase-2 mRNA expression. This ARB increased mucosal dimethylarginine dimethylaminohydrolase-1 (DDAH-1) gene expression and decreased elevated levels of matrix metalloproteinase-9, asymmetric dimethylarginine (ADMA), epidermal growth factor receptor (EGFR) mRNA and phosphorylated extracellular signal-regulated kinase 1 and 2 (pERK1/2). Histopathological evaluation corroborated biochemical findings. Overall efficacy of irbesartan was comparable to ranitidine, the widely used H2 receptor blocker. In conclusion, irbesartan exerts significant gastroprotection against indomethacin-induced mucosal damage via acid-inhibitory, anti-inflammatory, anti-apoptotic and extracellular matrix remodeling mechanisms that are probably mediated, at least partly, by down-regulating DDAH/ADMA and EGFR/ERK1/2 signaling.

Effects and possible mechanisms of Alpinia officinarum ethanol extract on indomethacin-induced gastric injury in rats

Context: Alpinia officinarum Hance (Zingiberoside) has a long history in treating gastrointestinal diseases, but its mechanisms of action are not yet known.Objective: To investigate the effects and underlying mechanisms of the ethanol extract of A. officinarum rhizomes in an indomethacin-induced gastric injury rat model.Material and methods: Indomethacin (0.3 g/kg) was orally administered to Sprague-Dawley rats to induce gastric damage; after 7 h, the rats were treated with 0.03, 0.09, or 0.18 g/kg of the plant extract, galangin (0.2 g/kg), or bismuth potassium citrate (0.08 g/kg), once a day for 6 days. Rats in the control group received an equivalent volume of vehicle solution for 6 days. Gastric damage was evaluated by gross ulcer and histological indexes. Cyclooxygenase and non-cyclooxygenase pathway proteins were quantified by western blotting and ELISA.Results: Alpinia officinarum extract ameliorated gastric injury in a dose-dependent manner, and 0.18 g/kg dose exhibited the best performance by reducing the gross ulcer (from 20.23 ± 1.38 to 1.66 ± 0.37) and histological (from 4.67 ± 1.03 to 0.33 ± 0.51) indexes, decreasing serum TNF-α level (14.17%), increasing serum VEGF level (1.58 times), increasing cyclooxygenase-1 level (1.25 times, p < 0.001) in the gastric mucosa, and reversing indomethacin-induced changes in the expression of non-cyclooxygenase pathway proteins (p < 0.05). Galangin was less effective as an antiulcer agent than the whole extract, indicating that other components also contributed to the protective effect.Conclusions: Alpinia officinarum extract and galangin exert antiulcer effects through cyclooxygenase and non-cyclooxygenase pathways validating use of galangin as a treatment for gastric damage.

Modulatory effect of silymarin on nuclear factor-erythroid-2-related factor 2 regulated redox status, nuclear factor-κB mediated inflammation and apoptosis in experimental gastric ulcer

Non-steroidal anti-inflammatory drugs (NSAIDs) consumption has been commonly associated with gastric mucosal lesions including gastric ulcer. Silymarin (SM) is a flavonoid mixture with anti-oxidant and anti-inflammatory activities which explain its protective role against hepatic and renal injuries. However, its impact on gastric ulcer has not yet been elucidated. Thus we went further to investigate the potential protective effects of SM against indomethacin-induced gastric injury in rats. Pretreatment with SM (50 mg/kg orally) attenuated the severity of gastric mucosal damage as evidenced by decreasing ulcer index (UI) and ulcer score, improvement of disturbed histopathologicl features to be insignificant with those induced by the reference anti-ulcer drug. Pretreatment with SM also suppressed gastric inflammation by decreasing myeloperoxidase activity, tumer necrosis factor-α (TNF- α) and interleukin 6 (IL6) levels along with nuclear factor kappa B p65 (NF-κB) expression. Meanwhile, SM prevent gastric oxidative stress via inhibition of lipid peroxides formation, enhancement of glutathione peroxidase, superoxide dismutase activities and up-regulation of nuclear factor-erythroid-2-related factor 2 (Nrf2), the redox-sensitive master regulator of oxidative stress signaling. In conclusion, the results herein revealed that SM has a gastro-protective effect which is mediated via suppression of gastric inflammation, oxidative stress, increased the anti-oxidant and the cyto-protective defense mechanisms.

Gastroprotective effect of ghrelin against indomethacin-induced gastric injury in rats: possible role of heme oxygenase-1 pathway

Ghrelin has been shown to ameliorate gastric injury by several mechanisms in experimental animal models. The present study aimed to investigate the effect of pretreatment with ghrelin on indomethacin-induced gastric injury in rats and the role of heme oxygenase-1(HO-1) pathway as a novel mechanism underlying the gastroprotective effect of ghrelin. In all groups studied, ulcer score (U.S), ulcer index (U.I) and preventive index (P.I) were evaluated and the gastric inflammatory biomarkers including levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and myeloperoxidase (MPO) activity as well as prostaglandin E2 (PGE2), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), HO-1 and bilirubin as an indicator of heme oxygenase activity were measured. Indomethacin induced significant elevation in U.S and U.I as well as the inflammatory and the oxidative markers and reduced the PGE2 in addition to HO-1 level and activity. Pretreatment with ghrelin reversed these results. In order to elucidate the possible role of HO-1 in mediating the protective effects of ghrelin, tin protoporphyrin (SnPP) HO-1 blocker was administrated; it significantly attenuated the gastroprotective effect of ghrelin. In conclusion HO-1 activity significantly contributes toward ghrelin-mediated gastroprotection.

Mechanisms by which endogenous glucocorticoid protects against indomethacin-induced gastric injury in rats.

We investigated the mechanisms underlying the protective action of glucocorticoids against indomethacin-induced gastric lesions. One-week adrenalectomized rats with or without corticosterone replacement (4 mg/kg sc) were administered indomethacin (25 mg/kg sc), and gastric secretion (acid, pepsin, and mucus), motility, microvascular permeability, and blood glucose levels were examined. Indomethacin caused gastric lesions in sham-operated rats, with an increase in gastric motility and microvascular permeability as well as a decrease in mucus secretion. Adrenalectomy significantly worsened the lesions and potentiated these functional disorders. Glucose levels were lowered by indomethacin in sham-operated rats, and this response was enhanced by adrenalectomy. The changes observed in adrenalectomized rats were prevented by supplementations of corticosterone at a dose mimicking the indomethacin-induced rise in corticosterone, whereas the protective effect of corticosterone was attenuated by RU-38486, a glucocorticoid receptor antagonist. We conclude that the gastroprotective action of endogenous glucocorticoids may be provided by their support of glucose homeostasis and inhibitory effects on enhanced gastric motility and microvascular permeability as well as maintaining the production of mucus.

Protective effect of cromakalim and diazoxide, and proulcerogenic effect of glibenclamide on indomethacin-induced gastric injury

We investigated the influences of the K + channel opening drugs cromakalim and diazoxide and their blocker, glibenclamide, in indomethacin-induced gastric injury in rats. Cromakalim (0.1 and 0.3 mg/kg) and diazoxide (10 and 30 mg/kg) produced dose-dependent gastroprotection at doses that were also effective on the cardiovascular system. Glibenclamide reversed their gastroprotective effects and aggravated indomethacin-induced gastric damage by its own. Cromakalim (10 −9–10 −5 M) and diazoxide (10 −9–10 −4 M) relaxed noradrenaline pre-contracted gastric arteries (94.59±1.58% and 93.86±2.99%, respectively). Their relaxant effects were inhibited by glibenclamide (10 −5 M) but not by indomethacin (10 −5 M) and l G-nitro- l-arginine (10 −4 M). Cromakalim (0.1 and 0.3 mg/kg) did not change gastric mucosal blood flow but increased the gastric mucosal vascular conductance in anaesthetized rats as measured by the hydrogen gas clearance technique. Indomethacin increased myeloperoxidase activity in the gastric mucosa, an effect which was reversed by cromakalim and diazoxide. Glibenclamide abolished their effects on myeloperoxidase activity and, alone, increased this parameter. Additionally, indomethacin caused infiltration of neutrophils which was reduced by cromakalim and diazoxide in a glibenclamide sensitive manner. The effects of cromakalim and diazoxide on mucosal myeloperoxidase activity, neutrophil infiltration and gastric injury correlated with each other. The effects of diazoxide (30 mg/kg) and glibenclamide (10 mg/kg) on blood glucose level were not correlated with their effects on gastric injury. Taken together, K + channel opening drugs show misoprostol-like protective effects in indomethacin-induced gastric injury which seems to be related to modulation of neutrophil function.

Oral trefoil peptides protect against ethanol- and indomethacin-induced gastric injury in rats

BACKGROUND & AIMS: The trefoil factors, a family of proteins abundantly expressed in gastrointestinal mucous cells, protect the epithelium in vitro. This study determines the effects of exogenously administered trefoil peptides on experimental injury in rats in vivo. METHODS: Gastric injury was induced by either intragastric absolute ethanol (1.0 mL) or subcutaneous indomethacin (20 mg/kg). Recombinant human spasmolytic polypeptide (rHSP) or rat intestinal trefoil factor (ITF) were administered at different doses and time points before or after injury. Vehicle or bovine serum albumin was used as control. The pH of the stomach contents was assessed when the rats were killed. Gastric injury was blindly evaluated macroscopically and histologically. Serum levels of rHSP and ITF were determined by an enzyme-linked immunosorbent assay. RESULTS: Oral rHSP and ITF markedly protected against both ethanol- and indomethacin-induced gastric injury (P < 0.005 at doses of 1-15 mg/rat) when given up to 2 hours before injury; no protection was noted by intraperitoneal rHSP against ethanol injury. Intraperitoneal rHSP protected against indomethacin-induced injury only at the maximal dose given (15 mg). Neither rHSP nor ITF altered gastric pH. Protection was not associated with systemic absorption of trefoil peptides. CONCLUSIONS: Topical trefoil peptides protect the gastric mucosa against ethanol- and indomethacin-induced gastric injuries. These peptides contribute to surface mucosal defense. (Gastroenterology 1996 Feb;110(2):489-97)

Role of tumor necrosis factor α release and leukocyte margination in indomethacin-induced gastric injury in rats

Background/Aims: Several studies have shown that polymorphonuclear neutrophil leukocyte (PMN) margination is an early and critical event in the pathogenesis of gastric mucosal injury caused by nonsteroidal anti-inflammatory drugs. Tumor necrosis factor (TNF) α is a proinflammatory cytokine that causes PMN margination by up-regulating expression of adhesion molecules on both PMN and endothelial cells. This study investigated whether substances that modulate TNF synthesis and release influence PMN margination and indomethacin-induced gastric damage. Methods: Rats were treated with several doses of indomethacin alone or in association with substances known to increase (interleukin 2 and lipopolysaccharide) or inhibit (pentoxifylline, dexamethasone, granulocyte colony-stimulating factor [G-CSF]) TNF synthesis and release. Results: Indomethacin administration caused dose-dependent damage and increased PMN margination and plasma TNF concentrations. Pretreatment with interleukin 2 and lipopolysaccharide significantly increased TNF release, PMN margination, and gastric mucosal damage, but administration of dexamethasone, pentoxifylline, and G-CSF provided almost total protection. The administration of G-CSF alone caused a significant increase in gastric PMN margination but protected against the indomethacin-induced gastropathy. Conclusions: Agents that regulate TNF synthesis and release influence gastric susceptibility to indomethacin by modulating PMN margination. G-CSF increased PMN infiltration but protected against the mucosal injury, suggesting that PMN margination alone is not sufficient to induce mucosal damage.