Protective and Healing Effects of Ghrelin and Risk of Cancer in the Digestive System.

Ghrelin is an endogenous ligand for the ghrelin receptor, previously known as the growth hormone secretagogue receptor. This hormone is mainly produced by endocrine cells present in the gastric mucosa. The ghrelin-producing cells are also present in other organs of the body, mainly in the digestive system, but in much smaller amount. Ghrelin exhibits a broad spectrum of physiological effects, such as stimulation of growth hormone secretion, gastric secretion, gastrointestinal motility, and food intake, as well as regulation of glucose homeostasis and bone formation, and inhibition of inflammatory processes. This review summarizes the recent findings concerning animal and human data showing protective and therapeutic effects of ghrelin in the gut, and also presents the role of growth hormone and insulin-like growth factor-1 in these effects. In addition, the current data on the possible influence of ghrelin on the carcinogenesis, its importance in predicting the risk of developing gastrointestinal malignances, as well as the potential usefulness of ghrelin in the treatment of cancer, have been presented.

Pretreatment with Warfarin Attenuates the Development of Ischemia/Reperfusion-Induced Acute Pancreatitis in Rats.

In acute pancreatitis (AP), pancreatic damage leads to local vascular injury, manifesting as endothelial damage and activation, increased vascular permeability, leukocyte rolling, sticking and transmigration to pancreatic tissue as well as activation of coagulation. Previous studies have shown that pretreatment with heparin or acenocoumarol inhibits the development of AP. The aim of the present study was to check the impact of pretreatment with warfarin, an oral vitamin K antagonist, on the development of ischemia/reperfusion-induced AP in rats. AP was induced by pancreatic ischemia followed by reperfusion of the gland. Warfarin (90, 180 or 270 µg/kg/dose) or vehicle were administered intragastrically once a day for 7 days before induction of AP. The effect of warfarin on the severity of AP was assessed 6 h after pancreatic reperfusion. The assessment included histological, functional, and biochemical analyses. Pretreatment with warfarin given at a dose of 90 or 180 µg/kg/dose increased the international normalized ratio and reduced morphological signs of pancreatic damage such as pancreatic edema, vacuolization of acinar cells, necrosis and the number of hemorrhages. These effects were accompanied by an improvement of pancreatic blood flow and a decrease in serum level amylase, lipase, pro-inflammatory interleukin-1ß and plasma level of D-dimer. In contrast, pretreatment with warfarin given at a dose of 270 µg/kg/dose led to an increase in severity of pancreatic damage and biochemical indicators of AP. In addition, this dose of warfarin resulted in deaths in some animals. Pretreatment with low doses of warfarin inhibits the development of AP induced by pancreatic ischemia followed by reperfusion.

Chemerin alleviates acute pancreatitis in the rat thorough modulation of NF-κB signal.

OBJECTIVE: Chemerin, an adipokine, works as the chemoattractant for the immune cells. The role of chemerin in the inflammatory reaction is controversial. Chemerin has been shown to aggravate the inflammatory response, but other studies demonstrated its anti-inflammatory influence. This study assessed the effects of chemerin on acute pancreatitis (AP) in vivo and in vitro. METHODS: For in vivo experiments male Wistar rats were used. For in vitro study rat pancreatic AR42J cells were employed. Chemerin (1, 5 or 10 µg/kg) was given to the rats prior to the induction of AP by subcutaneous caerulein infusion (25 µg/kg). For in vitro studies cells were subjected to caerulein (10 nM) with or without chemerin (100 nM). Serum amylase activity was measured by enzymatic method, serum TNFα concentration - by ELISA kit. Western-blot was used to examine cellular proteins. RESULTS: AP was confirmed by histological examination. Chemerin given to AP rats decreased histological manifestations of AP, reduced serum amylase activity and TNFα concentration. In AR42J cells subjected to caerulein with addition of chemerin signal for TNFα was reduced comparing to the cultures treated with caerulein alone. Analysis of the dynamics of nuclear translocation for p50, p65 and Bcl-3 points out to NF-κB attenuation as a mechanism of observed anti-inflammatory action of chemerin. CONCLUSION: Chemerin significantly alleviated severity of AP in the rat, this is possibly due to the inhibition of pro-inflammatory signaling in the pancreatic cells.

Potential Therapeutic Effects of Gut Hormones, Ghrelin and Obestatin in Oral Mucositis.

Chemotherapy and/or head and neck radiotherapy are frequently associated with oral mucositis. Oral pain, odynophagia and dysphagia, opioid use, weight loss, dehydration, systemic infection, hospitalization and introduction of a feeding tube should be mentioned as the main determinated effect of oral mucositis. Oral mucositis leads to a decreased quality of life and an increase in treatment costs. Moreover, oral mucositis is a life-threatening disease. In addition to its own direct life-threatening consequences, it can also lead to a reduced survival due to the discontinuation or dose reduction of anti-neoplasm therapy. There are numerous strategies for the prevention or treatment of oral mucositis; however, their effectiveness is limited and does not correspond to expectations. This review is focused on the ghrelin and obestatin as potentially useful candidates for the prevention and treatment of chemo- or/and radiotherapy-induced oral mucositis.

Correction: Warzecha, Z. et al. Protective Effect of Pretreatment with Acenocoumarol in Cerulein-Induced Acute Pancreatitis. Int. J. Mol. Sci. 2016, 17, 1709.

We would like to submit the correction to our published paper [...].

Correction: Warzecha, Z., et al. Therapeutic Effect of Low Doses of Acenocoumarol in the Course of Ischemia/Reperfusion-Induced Acute Pancreatitis in Rats. Int. J. Mol. Sci. 2017, 18, 882.

We would like to submit this correction to our published paper [...].

Correction: Bonior, J., et al. Capsaicin-Sensitive Sensory Nerves Are Necessary for the Protective Effect of Ghrelin in Cerulein-Induced Acute Pancreatitis in Rats. Int. J. Mol. Sci. 2017, 18, 1402.

We would like to submit the correction to our published paper [...].

Treatment with Obestatin-A Ghrelin Gene-Encoded Peptide-Reduces the Severity of Experimental Colitis Evoked by Trinitrobenzene Sulfonic Acid.

Obestatin is a 23-amino acid peptide derived from proghrelin, a common prohormone for ghrelin and obestatin. Previous studies showed that obestatin exhibited some protective and therapeutic effects in the gut. The aim of our presented study was to examine the effect of treatment with obestatin on trinitrobenzene sulfonic acid (TNBS)-induced colitis. In rats anesthetized with ketamine, colitis was induced through intrarectal administration of 25 mg of 2,4,6-trinitrobenzene sulfonic acid (TNBS). Obestatin was administered intraperitoneally at doses of 4, 8, or 16 nmol/kg, twice per day for four consecutive days. The first dose of obestatin was given one day before the induction of colitis, and the last one was given two days after administration of TNBS. Fourteen days after the induction of colitis, rats were anesthetized again with ketamine, and the severity of colitis was determined. The administration of obestatin had no effect on the parameters tested in rats without the induction of colitis. In rats with colitis, administration of obestatin at doses of 8 or 16 nmol/kg reduced the area of colonic damage, and improved mucosal blood flow in the colon. These effects were accompanied by a reduction in the colitis-evoked increase in the level of blood leukocytes, and mucosal concentration of pro-inflammatory interleukin-1ß. Moreover, obestatin administered at doses of 8 or 16 nmol/kg reduced histological signs of colonic damage. The administration of obestatin at a dose of 4 nmol/kg failed to significantly affect the parameters tested. Overall, treatment with obestatin reduced the severity of TNBS-induced colitis in rats. This effect was associated with an improvement in mucosal blood flow in the colon, and a decrease in local and systemic inflammatory processes.

Serum Concentrations of Angiopoietin-2 and Soluble fms-Like Tyrosine Kinase 1 (sFlt-1) Are Associated with Coagulopathy among Patients with Acute Pancreatitis.

In severe acute pancreatitis (SAP), systemic inflammation leads to endothelial dysfunction and activation of coagulation. Thrombotic disorders in acute pancreatitis (AP) include disseminated intravascular coagulation (DIC). Recently, angiopoietin-2 and soluble fms-like tyrosine kinase 1 (sFlt-1) were proposed as markers of endothelial dysfunction in acute states. Our aim was to assess the frequency of coagulation abnormalities in the early phase of AP and evaluate the relationships between serum angiopoietin-2 and sFlt-1 and severity of coagulopathy. Sixty-nine adult patients with AP were recruited: five with SAP, 15 with moderately severe AP (MSAP) and 49 with mild AP. Six patients were diagnosed with DIC according to International Society on Thrombosis and Haemostasis (ISTH) score. All patients had at least one abnormal result of routine tests of hemostasis (low platelet count, prolonged clotting times, decreased fibrinogen, and increased D-dimer). The severity of coagulopathy correlated with AP severity according to 2012 Atlanta criteria, bedside index of severity in AP and duration of hospital stay. D-dimers correlated independently with C-reactive protein and studied markers of endothelial dysfunction. Angiopoietin-2, D-dimer, and ISTH score were best predictors of SAP, while sFlt-1 was good predictor of MSAP plus SAP. In clinical practice, routine tests of hemostasis may assist prognosis of AP.

Effects of Melatonin and Its Analogues on Pancreatic Inflammation, Enzyme Secretion, and Tumorigenesis.

Melatonin is an indoleamine produced from the amino acid l-tryptophan, whereas metabolites of melatonin are known as kynuramines. One of the best-known kynuramines is N¹-acetyl-N¹-formyl-5-methoxykynuramine (AFMK). Melatonin has attracted scientific attention as a potent antioxidant and protector of tissue against oxidative stress. l-Tryptophan and kynuramines share common beneficial features with melatonin. Melatonin was originally discovered as a pineal product, has been detected in the gastrointestinal tract, and its receptors have been identified in the pancreas. The role of melatonin in the pancreatic gland is not explained, however several arguments support the opinion that melatonin is probably implicated in the physiology and pathophysiology of the pancreas. (1) Melatonin stimulates pancreatic enzyme secretion through the activation of entero-pancreatic reflex and cholecystokinin (CCK) release. l-Tryptophan and AFMK are less effective than melatonin in the stimulation of pancreatic exocrine function; (2) Melatonin is a successful pancreatic protector, which prevents the pancreas from developing of acute pancreatitis and reduces pancreatic damage. This effect is related to its direct and indirect antioxidant action, to the strengthening of immune defense, and to the modulation of apoptosis. Like melatonin, its precursor and AFMK are able to mimic its protective effect, and it is commonly accepted that all these substances create an antioxidant cascade to intensify the pancreatic protection and acinar cells viability; (3) In pancreatic cancer cells, melatonin and AFMK activated a signal transduction pathway for apoptosis and stimulated heat shock proteins. The role of melatonin and AFMK in pancreatic tumorigenesis remains to be elucidated.

Essential Role of Growth Hormone and IGF-1 in Therapeutic Effect of Ghrelin in the Course of Acetic Acid-Induced Colitis.

Previous studies have shown that ghrelin exhibits a protective and therapeutic effect in the gut. The aim of the present study was to examine whether administration of ghrelin affects the course of acetic acid-induced colitis and to determine what is the role of growth hormone (GH) and insulin-like growth factor-1 (IGF-1) in this effect. In sham-operated or hypophysectomized male Wistar rats, colitis was induced by enema with 1 mL of 3% solution of acetic acid. Saline or ghrelin (given at the dose of 8 nmol/kg/dose) was administered intraperitoneally twice a day. Seven days after colitis induction, rats were anesthetized and the severity of the colitis was assessed. Treatment with ghrelin reduced the area of colonic mucosa damage in pituitary-intact rat. This effect was associated with increase in serum levels of GH and IGF-1. Moreover, administration of ghrelin improved blood flow in colonic mucosa and mucosal cell proliferation, as well as reduced mucosal concentration of proinflammatory interleukin-1ß (IL-1ß) and activity of myeloperoxidase. Hypophysectomy reduced serum levels of GH and IGF-1 and increased the area of colonic damage in rats with colitis. These effects were associated with additional reduction in mucosal blood follow and DNA synthesis when compared to pituitary-intact rats. Mucosal concentration of IL-1ß and mucosal activity of myeloperoxidase were maximally increased. Moreover, in hypophysectomized rats, administration of ghrelin failed to affect serum levels of GH or IGF-1, as well as the healing rate of colitis, mucosal cell proliferation, and mucosal concentration of IL-1ß, or activity of myeloperoxidase. We conclude that administration of ghrelin accelerates the healing of the acetic acid-induced colitis. Therapeutic effect of ghrelin in experimental colitis is mainly mediated by the release of endogenous growth hormone and IGF-1.

Capsaicin-Sensitive Sensory Nerves Are Necessary for the Protective Effect of Ghrelin in Cerulein-Induced Acute Pancreatitis in Rats.

Ghrelin was shown to exhibit protective and therapeutic effect in the gut. Aim of the study was to investigate the role of sensory nerves (SN) in the protective effect of ghrelin in acute pancreatitis (AP). Studies were performed on male Wistar rats or isolated pancreatic acinar cells. After capsaicin deactivation of sensory nerves (CDSN) or treatment with saline, rats were pretreated intraperitoneally with ghrelin or saline. In those rats, AP was induced by cerulein or pancreases were used for isolation of pancreatic acinar cells. Pancreatic acinar cells were incubated in cerulein-free or cerulein containing solution. In rats with intact SN, pretreatment with ghrelin led to a reversal of the cerulein-induced increase in pancreatic weight, plasma activity of lipase and plasma concentration of tumor necrosis factor-α (TNF-α). These effects were associated with an increase in plasma interleukin-4 concentration and reduction in histological signs of pancreatic damage. CDSN tended to increase the severity of AP and abolished the protective effect of ghrelin. Exposure of pancreatic acinar cells to cerulein led to increase in cellular expression of mRNA for TNF-α and cellular synthesis of this cytokine. Pretreatment with ghrelin reduced this alteration, but this effect was only observed in acinar cells obtained from rats with intact SN. Moreover, CDSN inhibited the cerulein- and ghrelin-induced increase in gene expression and synthesis of heat shock protein 70 (HSP70) in those cells. Ghrelin exhibits the protective effect in cerulein-induced AP on the organ and pancreatic acinar cell level. Sensory nerves ablation abolishes this effect.

Therapeutic Effect of Low Doses of Acenocoumarol in the Course of Ischemia/Reperfusion-Induced Acute Pancreatitis in Rats.

Intravascular activation of coagulation is observed in acute pancreatitis and is related to the severity of this inflammation. The aim of our study was to evaluate the impact of acenocoumarol therapy on the course of acute pancreatitis induced in male rats by pancreatic ischemia followed by reperfusion. Acenocoumarol at a dose of 50, 100, or 150 µg/kg/dose was administered intragastrically once a day, starting the first dose 24 h after the initiation of pancreatic reperfusion. RESULTS: Histological examination showed that treatment with acenocoumarol reduces pancreatic edema, necrosis, and hemorrhages in rats with pancreatitis. Moreover, the administration of acenocoumarol decreased pancreatic inflammatory infiltration and vacuolization of pancreatic acinar cells. These findings were accompanied with a reduction in the serum activity of lipase and amylase, concentration of interleukin-1ß, and plasma d-Dimer concentration. Moreover, the administration of acenocoumarol improved pancreatic blood flow and pancreatic DNA synthesis. Acenocoumarol given at a dose of 150 µg/kg/dose was the most effective in the treatment of early phase acute pancreatitis. However later, acenocoumarol given at the highest dose failed to exhibit any therapeutic effect; whereas lower doses of acenocoumarol were still effective in the treatment of acute pancreatitis. CONCLUSION: Treatment with acenocoumarol accelerates the recovery of ischemia/reperfusion-induced acute pancreatitis in rats.

Molecular Ghrelin System in the Pancreatic Acinar Cells: The Role of the Polypeptide, Caerulein and Sensory Nerves.

Ghrelin (GHRL) is an endogenous ligand for the growth hormone secretagogue receptor (GHS-R). Experimental studies showed that GHRL protects the stomach and pancreas against acute damage, but the effect of GHRL on pancreatic acinar cells was still undetermined. AIM: To investigate the effect of GHRL and caerulein on the functional ghrelin system in pancreatic acinar cells taking into account the role of sensory nerves (SN). METHODS: Experiments were carried out on isolated pancreatic acinar cells and AR42J cells. Before acinar cells isolation, GHRL was administered intraperitoneally at a dose of 50 µg/kg to rats with intact SN or with capsaicin deactivation of SN (CDSN). After isolation, pancreatic acinar cells were incubated in caerulein-free or caerulein containing solution. AR42J cells were incubated under basal conditions and stimulated with caerulein, GHRL or a combination of the above. RESULTS: Incubation of isolated acinar cells with caerulein inhibited GHS-R and GHRL expression at the level of mRNA and protein in those cells. Either in rats with intact SN or with CDSN, administration of GHRL before isolation of acinar cells increased expression of GHRL and GHS-R in those cells and reversed the caerulein-induced reduction in expression of those parameters. Similar upregulation of GHS-R and GHRL was observed after administration of GHRL in AR42J cells. CONCLUSIONS: GHRL stimulates its own expression and expression of its receptor in isolated pancreatic acinar cells and AR42J cells on the positive feedback pathway. This mechanism seems to participate in the pancreatoprotective effect of GHRL in the course of acute pancreatitis.

Angiopoietin-2 Is an Early Indicator of Acute Pancreatic-Renal Syndrome in Patients with Acute Pancreatitis.

Within the first week of the disease, acute kidney injury (AKI) is among the most common causes of mortality in acute pancreatitis (AP). Recently, serum angiopoietin-2 (Ang-2) has been associated with hyperdynamic state of the systemic circulation. The aim of this study was to examine the associations between Ang-2 and the clinical AP severity during the first 72 hours of the disease, and organ disfunction, including AKI. Methods. Study included patients admitted to the surgery ward, diagnosed with AP. AKI was diagnosed according to KDIGO guidelines and renal failure according to modified Marshall scoring system. Ang-2 was determined in serum with ELISA. Results. AP was classified as mild (MAP) in 71% of patients, moderately severe (MSAP) in 22%, and severe (SAP) in 8%. During the first 72 hours of AP, 11 patients developed AKI and 6 developed renal failure. Ang-2 at 24, 48, and 72 hours following the onset of AP symptoms significantly predicted SAP and MSAP, as well as AKI and renal failure. Also, Ang-2 significantly correlated with acute phase proteins as well as with the indicators of renal disfunction. Conclusions. Serum Ang-2 may be a relevant predictor of AP severity, in particular of the development of AP-renal syndrome.

Protective Effect of Pretreatment with Acenocoumarol in Cerulein-Induced Acute Pancreatitis.

Coagulation is recognized as a key player in inflammatory and autoimmune diseases. The aim of the current research was to examine the effect of pretreatment with acenocoumarol on the development of acute pancreatitis (AP) evoked by cerulein. METHODS: AP was induced in rats by cerulein administered intraperitoneally. Acenocoumarol (50, 100 or 150 µg/kg/dose/day) or saline were given once daily for seven days before AP induction. RESULTS: In rats with AP, pretreatment with acenocoumarol administered at the dose of 50 or 100 µg/kg/dose/day improved pancreatic histology, reducing the degree of edema and inflammatory infiltration, and vacuolization of acinar cells. Moreover, pretreatment with acenocoumarol given at the dose of 50 or 100 µg/kg/dose/day reduced the AP-evoked increase in pancreatic weight, serum activity of amylase and lipase, and serum concentration of pro-inflammatory interleukin-1ß, as well as ameliorated pancreatic DNA synthesis and pancreatic blood flow. In contrast, acenocoumarol given at the dose of 150 µg/kg/dose did not exhibit any protective effect against cerulein-induced pancreatitis. CONCLUSION: Low doses of acenocoumarol, given before induction of AP by cerulein, inhibit the development of that inflammation.

Exogenous Ghrelin Accelerates the Healing of Acetic Acid-Induced Colitis in Rats.

Previous studies have shown that ghrelin reduces colonic inflammation induced by trinitrobenzene sulfonic acid and dextran sodium sulfate. In the present study we determined the effect of treatment with ghrelin on the course of acetic acid-induced colitis in rats. Rectal administration of 3% acetic acid solution led to induction of colitis in all animals. Damage of the colonic wall was accompanied by an increase in mucosal concentration of pro-inflammatory interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α), as well mucosal activity of myeloperoxidase. Moreover, induction of colitis led to a reduction in colonic blood flow and DNA synthesis. Administration of ghrelin after induction of colitis led to faster regeneration of the colonic wall and reduction in colonic levels of IL-1ß, TNF-α, and myeloperoxidase. In addition, treatment with ghrelin improved mucosal DNA synthesis and blood flow. Our study disclosed that ghrelin exhibits a strong anti-inflammatory and healing effect in acetic acid-induced colitis. Our current observation in association with previous findings that ghrelin exhibits curative effect in trinitrobenzene sulfonic acid- and dextran sodium sulfate-induced colitis suggest that therapeutic effect of ghrelin in the colon is universal and independent of the primary cause of colitis.

Determination of serum neutrophil gelatinase-associated lipocalin at the early stage of acute pancreatitis.

AIM: e aim of the study was to assess the diagnostic value of serum concentrations of neutrophil gelatinase-associated lipocalin (sNGAL) for the determination of the severity of acute pancreatitis (AP) at the early stage of the disease. MATERIALS AND METHOD: The study group consisted of 65 patients(34 men and 31 women),aged 62.2 ± 16.0, admitted to the Surgery Department of the District Hospital in Sucha Beskidzka, Poland, with the diagnosis of AP according to the revised Atlanta classification (2012). sNGAL was measured with ELISA at 24, 48 and 72 hours following the onset of AP symptoms. The correlations were analyzed between sNGAL and clinical, as well as laboratory parameters, used for the assessment of AP severity. RESULTS: Severe AP was associated with higher sNGAL at 24, 48 and 72 hours, while moderately severe AP was associated with higher sNGAL at 48 and 72 hours as compared to mild disease. The BISAP score ≥3 during the first 24 hours of hospital stay, and the duration of hospital stay were significantly correlated with sNGAL. Also, sNGAL positively correlated with white blood cells, C-reactive protein and fibrinogen and negatively with albumin throughout the study. The diagnostic accuracy of sNGAL for the differentiation between mild AP and more severe disease was 75%, 77% and 85% at 24, 48 and 72 hours, respectively. CONCLUSIONS: Serum NGAL concentrations are associated with inflammatory markers, BISAP score and the severity of AP. sNGAL may serve as an additional prognostic biomarker in the early assessment of AP severity.

[Experimental models of acute pancreatitis]. / Eksperymentalne modele ostrego zapalenia trzustki

Acute pancreatitis is a severe disease with high mortality. Clinical studies can bring some data about etiology, pathogenesis and the course of acute pancreatitis. However, studies concerning early events of this disease and the new concepts of treatment cannot be performed on humans, due to ethical reasons. Animal models of acute pancreatitis have been developed to solve this problem. This review presents currently used experimental models of acute pancreatitis, their properties and clinical relevance. Experimental models of acute pancreatitis can be divided into in vivo (non-invasive and invasive) and ex vivo models. The onset, development, severity and extent of acute pancreatitis, as well as the mortality, vary considerably between these different models. Animal models reproducibly produce mild, moderate or severe acute pancreatitis. One of the most commonly used models of acute pancreatitis is created by administration of supramaximal doses of cerulein, an analog of cholecystokinin. This model produces acute mild edematous pancreatitis in rats, whereas administration of cerulein in mice leads to the development of acute necrotizing pancreatitis. Acute pancreatitis evoked by retrograde administration of sodium taurocholate into the pancreatic duct is the most often used model of acute severe necrotizing pancreatitis in rats. Ex vivo models allow to eliminate the influence of hormonal and nervous factors on the development of acute pancreatitis.

[Involvement of endogenous tachykinins in the development of jejunal mucosa injury induced by on-steroidal anti-inflammatory drugs]. / Udzial endogennych tachykinin w powstawaniu uszkodzen blony sluzowej jelita czczego wywolanych niesterydowymi lekami przeciwzapalnymi.

UNLABELLED: Previous studies have shown that tachykinins, the largest family of neuropeptides, affect the development of mucosal damage in the stomach and colon. The aim of the study was to assess the influence of tachykinins receptors antagonists on the development of the mucosa injury in the proximal and distal jejunum. MATERIAL AND METHODS: Mucosal damage was induced by administration of non-steroidal anti inflammatory drugs (NSAIDs), indomethacin, celecoxib or combination of indomethacin plus celecoxib given intragastrically. NK-1 receptor antagonist (SR 140333), NK-2 receptor antagonist (SR 48968) and NK-3 receptor antagonist (SR 142801) were administered intraperitoneally twice, 30 min before treatment with NSAID and again 24 h later, 30 min before the end of the experiment. RESULTS: Administration of indomethacin, a relatively selective inhibitor for cyclooxygenase-1 (COX-1), induced mucosal lesions in the jejunum. Lesions area in the distal jejunum was 8-fold bigger than in the proximal jejunum. This effect was associated with a significant reduction in mucosal blood flow and an increase in mucosal concentration of pro-inflammatory interleukin-1beta (IL-1beta). Celecoxib, selective inhibitor for COX-2 failed to induce mucosal lesions and did not affect the mucosal blood flow and IL-1beta concentration in the proximal and distal jejunum. In rats treated with a combination of indomethacin plus celecoxib, ulcers reached maximal area. This effect was associated with the highest concentration of mucosal IL-1beta and maximal reduction in mucosal blood flow. Administration of NK-1 receptor antagonist, SR 140333 reduced jejunal damage induced by indomethacin given alone or in combination with celecoxib. This effect was associated with significant reduction in mucosal concentration of IL-1beta. Effect of SR 140333 on mucosal blood flow was statistically insignificant. Neither NK-2 nor NK-3 receptor inhibitor affected mucosal blood flow, IL-1beta concentration area of NSAIDs-induced mucosal damage in the jejunum. CONCLUSIONS: Blockade of NK-1 receptor protects the jejunum against NSAIDs-induced mucosal injury and reduces local inflammation. This observation indicates the involvement of endogenous tachykinins in deleterious effects of NSAID.