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Portograma aéreo o portograma de aire (PA), se define como la presencia de aire en el sistema venoso portomesentérico. Neumatosis intestinal (NI) se define como la presencia de aire en la pared intestinal, independiente de su causa o localización. La principal etiología de estas alteraciones es la isquemia intestinal aguda y en general, se consideran predictores de perforación intestinal y de mal pronóstico. Un pequeño grupo de pacientes con PA y/o NI pueden evolucionar sin complicaciones e incluso cursan sin manifestaciones clínicas. Presentamos el caso de una paciente con antecedente quirúrgico inmediato de gastrectomía total y reconstrucción en Y de Roux, que evidenció en tomografía computarizada (TC) de abdomen de control PA y NI, sin alteraciones clínicas significativas asociadas. Hepatic portal venous gas (HPVG) is defined as the presence of air in the portal venous system. Pneumatosis intestinalis (PI) is defined as the presence of air within the bowel wall, regardless of its cause or location. Its main etiology is the intestinal ischemia and are generally considered predictors of intestinal perforation and wrong prognosis. A small group of patients with HPVG and PI may have a different clinical course, without complications and clinical manifestations. We report the case of a patient with immediate surgical history of total gastrectomy and Roux-en-Y reconstruction, which showed in computed tomography (CT) of the abdomen HPVG and PI, without associated clinically significant changes. © 2018, Sociedad Chilena de Radiologia. All rights reserved.

Background Acute mesenteric ischemia is a life-threatening clinical entity. 2-Aminoethoxydiphenyl borate (2-APB) is a membrane-permeable modulator of intracellular inositol triphosphate-induced calcium release. We investigated the effects of different 2-APB doses on intestinal ischemia-reperfusion injury in an experimental rat model. Methods We divided 24 Wistar albino rats into four groups: sham, control, ischemia-reperfusion +2 mg/kg 2-APB, and ischemia-reperfusion +4 mg/kg 2-APB. The sham group only underwent laparotomy for 1 h 30 min. A 30-min period of mesenteric ischemia was induced in the control and two treatment groups, followed by 1 h of reperfusion. Before the laparotomy, 2 mg/kg and 4 mg/kg 2-APB was administered i.v. in the treatments groups, and blood samples were collected after reperfusion. Serum levels of malondialdehyde, superoxide dismutase, glutathione, total antioxidant capacity, tumor necrosis factor (TNF)-alpha, and interleukin-6 were analyzed. Intestinal tissues were taken for histopathological, DNA fragmentation, and terminal deoxynucleotidyl transferase dUTP nick end labeling analyses to determine the proportion of apoptotic cells. Results 2-APB reduced serum malondialdehyde, TNF-alpha, and interleukin-6 levels. However, superoxide dismutase and total antioxidant capacity levels increased significantly in the 4-mg/kg 2-APB group (p < 0.05). The intestinal histopathological injury scores were significantly higher in the control group; these injuries were prevented in the 4-mg/kg 2-APB dose group. DNA damage after ischemia-perfusion decreased significantly in the 4-mg/kg 2-APB group compared with the control group. Conclusion 2-APB decreases oxidative stress and cell injury. Administering 4 mg/kg 2-APB prevented ischemia-perfusion injury by diminishing histological damage.

Background: Tempol is a stable piperidine nitroxide of low molecular weight that permeates biological membranes and scavenges superoxide anions in vitro. In a variety of animal models, deleterious effects of reperfusion injury on both local and remote organs have been demonstrated. In this study, we aimed to investigate the effects of a membrane-permeable radical scavenger, Tempol, on local and remote organ injuries caused by intestinal ischemia/reperfusion (I/R) in rats. Materials and methods: Male Wistar-albino rats were randomized into three groups: (I) Sham-operated control group, laparotomy without I/R injury (n = 12); (II) Intestinal I/R group, 60 min of ischemia by superior mesenteric artery occlusion followed by 2-h of reperfusion (n = 12); and (III) I/R + Tempol-treated group, identical to I/R group except for Tempol administration, 30 mg/kg bolus injection 5 min before reperfusion, followed by an infusion of 30 mg/kg/h intravenously (n = 12). Histopathologically, intestinal mucosal lesions were assessed by Chiu's classification, and pulmonary parenchymal damage was appraised by pulmonary neutrophil infiltration and acute lung injury scaling. Biochemically, myeloperoxidase activity, malondialdehyde, glutathione, and nitrite/nitrate (NOx) levels were determined in both intestinal mucosa and lung parenchyma. Evans blue dye concentration and organ wet/dry weight ratios were used as a marker of organ edema. Animal survival was observed up to 1 week. Results: Intestinal mucosal lesions and pulmonary parenchymal damage were significantly attenuated with Tempol treatment, histopathologically (P < 0.05). Tempol administration significantly reduced myeloperoxidase activity and malondialdehyde levels, and also significantly increased glutathione and NOx levels of both intestinal and lung tissues, biochemically (P < 0.05). Evans blue dye extravasation and wet/dry weight ratios of organs were significantly reduced with Tempol injection (P < 0.05). The survival rates of rats in Tempol-treated group were significantly higher than that of I/R-treated group (P < 0.05). Conclusions: The present study suggests that Tempol administration significantly reduces both local and remote organ injuries caused by intestinal I/R before and throughout the reperfusion period. Further clinical studies are needed to clarify whether Tempol may be a useful therapeutic agent to use in particular operations where the reperfusion injury occurs. © 2008 Elsevier Inc. All rights reserved.

To investigate the role of interleukin (IL)-10 gene therapy on the reperfusion-induced lung injury, we utilised the technique of liposomal gene delivery before the induction of intestinal ischemia. Plasmid DNA encoding human IL10 (hIL-10) or empy vector was injected intraperitoneally 24 h before the study. Male Balb/c mice randomized into three groups: Sham operated control (n = 12), empty plasmid vector (n = 12), and hIL-10 gene therapy group (n = 12). The ischemia was generated by selective occlusion of superior mesenteric artery for 60 min. and followed by reperfusion for 30 min. Lung tissue neutrophil infiltration was determined by myeloperoxidase assay and neutrophil counts. For the determination of lung tissue microvascular permeability, Evans blue dye injection was made and the lung edema was assesed by wet/dry ratio. hIL-10 protein expression was studied by immunostaining and ELISA. We found that pre-ischemic hIL-10 overexpression attenuated dye extravasation, leukocyte sequestration and reduced pulmonary tissue injury compared to the empty vector-injected control. Our study indicates that pre-ischemic hIL-10 overexpression attenuates lung injury caused by intestinal ischemia-reperfusion. © 2005 Tohoku University Medical Press.

Trimetazidine (TMZ), a potent antioxidant agent, has been used to protect the myocardium, liver and kidney from ischemia reperfusion (IR) injury. We investigated the effect of TMZ, a cellular anti-ischemic agent and a free radical scavenger, on 60 min of warm intestinal IR injury in rats. Sprague-Dawley rats were divided into three groups: a sham-operated group (no IR injury, n = 8), an ischemic control group (control, n = 8), and a TMZ- treated group (3 mg/kg, n = 8). Malondialdehyde (MDA) levels, myeloperoxidase (MPO) activity, and mucosal damage were investigated after 120 min of reperfusion. MDA levels and MPO activity were more elevated and histopathological damage more severe in the control group than in the sham group (P < 0.05). MDA levels and MPO activity were lower and there was less histopathological damage in the TMZ group than in the control group (P < 0.05). Accumulation of lipid peroxidation products and neutrophils in mucosal tissues were significantly inhibited by TMZ treatment. We conclude that pretreatment of rats with TMZ before intestinal ischemia attenuates but does not prevent, histological damage.

Gut homeostasis results from complex neuro-immune interactions aimed at triggering stereotypical and specific programs of coordinated mucosal secretion and powerful motor propulsion. A prominent role in the regulation of this highly integrated network, comprising a variety of immune/inflammatory cells and the enteric nervous system, is played by purinergic mediators. The cells of the digestive tract are literally plunged into a "biological sea" of functionally active nucleotides and nucleosides, which carry out the critical task of driving regulatory interventions on cellular functions through the activation of P1 and P2 receptors. Intensive research efforts are being made to achieve an integrated view of the purinergic system, since it is emerging that the various components of purinergic pathways (i.e., enzymes, transporters, mediators and receptors) are mutually linked entities, deputed to finely modulating the magnitude and the duration of purinergic signaling, and that alterations occurring in this balanced network could be intimately involved in the pathophysiology of several gut disorders. This review article intends to provide a critical appraisal of current knowledge on the purinergic system role in the regulation of gastrointestinal functions, considering these pathways as a whole integrated network, which is capable of finely controlling the levels of bioactive nucleotides and nucleosides in the biophase of their respective receptors. Special attention is paid to the mechanisms through which alterations in the various compartments of the purinergic system could contribute to the pathophysiology of gut disorders, and to the possibility of counteracting such dysfunctions by means of pharmacological interventions on purinergic molecular targets. © 2013 Elsevier Inc.

Gut homeostasis results from complex neuro-immune interactions aimed at triggering stereotypical and specific programs of coordinated mucosal secretion and powerful motor propulsion. A prominent role in the regulation of this highly integrated network, comprising a variety of immune/inflammatory cells and the enteric nervous system, is played by purinergic mediators. The cells of the digestive tract are literally plunged into a "biological sea" of functionally active nucleotides and nucleosides, which carry out the critical task of driving regulatory interventions on cellular functions through the activation of P1 and P2 receptors. Intensive research efforts are being made to achieve an integrated view of the purinergic system, since it is emerging that the various components of purinergic pathways (i.e., enzymes, transporters, mediators and receptors) are mutually linked entities, deputed to finely modulating the magnitude and the duration of purinergic signaling, and that alterations occurring in this balanced network could be intimately involved in the pathophysiology of several gut disorders. This review article intends to provide a critical appraisal of current knowledge on the purinergic system role in the regulation of gastrointestinal functions, considering these pathways as a whole integrated network, which is capable of finely controlling the levels of bioactive nucleotides and nucleosides in the biophase of their respective receptors. Special attention is paid to the mechanisms through which alterations in the various compartments of the purinergic system could contribute to the pathophysiology of gut disorders, and to the possibility of counteracting such dysfunctions by means of pharmacological interventions on purinergic molecular targets. © 2013 Elsevier Inc.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:28:40Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:42:55Z : No. of bitstreams: 1 2-s2.0-84874805360.pdf: 1394575 bytes, checksum: 573bfb2af4add411de8aa3a8efac6c77 (MD5) Made available in DSpace on 2014-05-27T11:28:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-03-15 Background: Intestinal ischemia/reperfusion (IR) injury is a serious and triggering event in the development of remote organ dysfunction, from which the lung is the main target. This condition is characterized by intense neutrophil recruitment, increased microvascular permeability. Intestinal IR is also responsible for induction of adult respiratory distress syndrome, the most serious and life-threatening form of acute lung injury. The purpose of this study was to investigate the effect of annexin-A1 protein as an endogenous regulator of the organ remote injury induced by intestinal ischemia/reperfusion. Male C57bl/6 mice were subjected to intestinal ischemia, induced by 45 min occlusion of the superior mesenteric artery, followed by reperfusion. Results: The intestinal ischemia/reperfusion evoked a high intensity lung inflammation as indicated by the number of neutrophils as compared to control group. Treatment with annexin-A1 peptidomimetic Ac2-26, reduced the number of neutrophils in the lung tissue and increased its number in the blood vessels, which suggests a regulatory effect of the peptide Ac2-26 in the neutrophil migration. Moreover, the peptide Ac2-26 treatment was associated with higher levels of plasma IL-10. Conclusion: Our data suggest that the annexin-A1 peptidomimetic Ac2-26 treatment has a regulatory and protective effect in the intestinal ischemia/reperfusion by attenuation of the leukocyte migration to the lung and induction of the anti-inflammatory cytokine IL-10 release into the plasma. The anti-inflammatory action of annexin-A1 and its peptidomimetic described here may serve as a basis for future therapeutic approach in mitigating inflammatory processes due to intestinal ischemia/reperfusion. © 2013 Guido et al.; licensee BioMed Central Ltd. Department of Biology; Institute of Biosciences Letras e Ciências Exatas (IBILCE) São Paulo State University (UNESP), São José do Rio Preto, SP 15054-000 Department of Pharmacology Institute of Biomedical Sciences (ICB) University of São Paulo (USP), São Paulo, 05508-900 Department of Basic Science in Health Faculty of Medicine (FM) Federal University of Mato Grosso (UFMT), Mato Grosso, MT 78060-900 Department of Biology; Institute of Biosciences Letras e Ciências Exatas (IBILCE) São Paulo State University (UNESP), São José do Rio Preto, SP 15054-000

Acute gastric volvulus is a rare acute life-threatening surgical emergency that involves abnormal rotation of the stomach along one or both of its axes by more than 180° resulting in closed-loop obstruction. Acute gastric volvulus can result in complications such as gastric ischemia, necrosis, and perforation; as a consequence, it requires rapid recognition and need immediate surgical treatment [1, 2]. Gastric volvulus has been classically classified into: (1) organoaxial (OA), when the stomach rotates around an axis line connecting the gastroesophageal junction and pylorus (Fig. 1a), (2) mesentero-axial (MA), when the stomach rotates around an imaginary transverse line connecting the middle of lesser and greater curvatures of the stomach (Fig. 1b), and (3) mixed-type (MT), when features of both OA and MA are present. The role and radiological features of upper gastrointestinal barium studies in acute gastric volvulus has just been extensively described [3, 4]. However, a patient presenting to emergency room with an acute abdomen may undergo directly a CT scan as first imaging examination. As a consequence, the radiologist should be confident with the tomographic appearance of this pathology. We describe the CT findings of a MT acute gastric volvulus.

Background: Activated protein C (APC) is a serine protease with anticoagulant and antiinflammatory activities. The delaying effects of remote reperfusion injury on the wound-healing process in colonic anastomoses have been previously shown. In this study, we aimed to investigate whether APC protects against deleterious systemic effects of intestinal ischemia/reperfusion (I/R) injury on colonic anastomotic wound healing process. Methods: Male Wistar-albino rats were randomly allocated into 4 groups, and a left colonic anastomosis was performed in all animals: (1) sham-operated group, simultaneously with left colonic anastomosis, the superior mesenteric artery and collateral branches were divided from the celiac axis, and the inferior mesenteric artery were isolated but not occluded (group 1, n = 12), (2) sham + APC group, identical to group 1 except for APC treatment (100 μg/kg, intravenously, 15 minutes before construction of the colonic anastomosis), (group 2, n = 12), (3) intestinal I/R group, 60 minutes of superior mesenteric ischemia followed by reperfusion (group 3, n = 12), and (4) APC-treated group, (100 μg/kg, intravenously, 15 minutes before reperfusion) (group 4, n = 12). All animals were sacrificed, and colonic anastomotic bursting pressures were measured in vivo on day 7. Tissue samples were obtained for analysis of hydroxyproline contents, nitrate/nitrite levels, and activities of oxidative and antioxidative enzymes. The plasma levels of proinflammatory cytokines and D-dimer were also measured. Results: Intestinal I/R led to significant decreases in colonic anastomotic bursting pressures, tissue hydroxyproline contents, and activities of antioxidative enzymes, along with increases in tissue nitrate/nitrite levels, activities of oxidative enzymes, and plasma levels of proinflammatory cytokines and D-dimer (P < .05). However, APC treatment led to significant increases in colonic anastomotic bursting pressures, tissue hydroxyproline contents, and activities of antioxidative enzymes, along with decreases in tissue nitrate/nitrite levels, activities of oxidative enzymes, and plasma levels of proinflammatory cytokines and D-dimer (P < .05). Conclusion: This study clearly showed that APC treatment prevented the delaying effects of remote I/R injury on colonic anastomotic wound healing process. Further clinical studies are required to determine whether APC has a useful role in the enhancement of colonic anastomotic wound healing after particular operations in which I/R injury occurs. © 2008 Elsevier Inc. All rights reserved.

Background: Pyrrolidine dithiocarbamate (PDTC) is a low-molecular-weight thiol antioxidant and potent inhibitor of nuclear factor-κB (NF-κB) activation. It has been shown to attenuate harmful effects of ischemia/reperfusion (I/R) injury in many organs. In recent animal studies, destructive effects of reperfusion injury has been demonstrated. In this study, we aimed to investigate whether PDTC prevents harmful effects of superior mesenteric I/R injury in rats. Methods: Wistar-albino rats were randomly allocated into the following 4 groups: (1) sham-operated group-these animals underwent laparotomy without I/R injury (group I, n = 12); (2) sham+PDTC group-identical to sham-operated rats except for the administration of PDTC (100 mg/kg intravenous bolus) 30 minutes prior to the commencement of the experimental period (group II, n = 12); (3) I/R group-these animals underwent laparotomy and 60 minutes of ischemia followed by 120 minutes of reperfusion (group III, n = 12); (4) PDTC-treated group (100 mg/kg, intravenously, before the I/R, group IV, n = 12). All animals were killed, and intestinal tissue samples were obtained for investigation of intestinal mucosal injury, myeloperoxidase (MPO) activity, malondialdehyde (MDA) levels, glutathione (GSH) levels, and intestinal edema. Results: There was a statistically significant decrease in GSH levels, along with an increase in intestinal mucosal injury scores, MPO activity, MDA levels, and intestinal tissue wet-to-dry weight ratios in group III when compared to groups I, II, and IV (P < .05). However, PDTC treatment led to a statistically significant increase in GSH levels, along with a decrease in intestinal mucosal injury scores, MPO activity, MDA levels, and intestinal tissue wet-to-dry weight ratios in group IV (P < .05). Conclusions: This study showed that PDTC treatment significantly prevented the reperfusion injury caused by superior mesenteric I/R. Further clinical studies are needed to clarify whether PDTC may be a useful therapeutic agent to use in particular operations where the reperfusion injury occurs. © 2007 Excerpta Medica Inc. All rights reserved.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:21:21Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:39:55Z : No. of bitstreams: 1 2-s2.0-23744472010.pdf: 529510 bytes, checksum: d4ae79c794c8b79242af56d545a4b4e6 (MD5) Made available in DSpace on 2014-05-27T11:21:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-06-01 The intestinal ischemia is unusual in vascular surgery emergency. Its main causes are embolisms and arterial thrombosis. In addition to severe ischemia, reperfusion of the ischemic tissues can lead to several complications that may worsen the ischemic lesion and produce a life threatening situation caused by systemic alterations. Intestinal tissue injuries due to ischemia and reperfusion have been demonstrated in clinical and experimental studies, in which pathophysiology and adequate treatment were also studied. The great variety of experimental models used and results achieved reflect the need for an intestinal ischemia and reperfusion experimental model that is simple, reproducible and consistent, in order to search for treatments that can reduce the damage caused by this situation. In this review, the main pathophysiologic aspects and the most used experimental models will be reviewed. Copyright © 2005 by Sociedade Brasileira de Angiologia e Cirurgia Vascular. Aluno Regular do Curso de Pós-Graduação Nível Mestrado Universidade Estadual Paulista (UNESP), Botucatu, SP Livre-Docente da Disciplina de Cirurgia Vascular Departamento de Cirurgia e Ortopedia UNESP, Botucatu, SP Faculdade de Medicina de Botucatu Departamento de Cirurgia e Ortopedia, Botucatu, SP Aluno Regular do Curso de Pós-Graduação Nível Mestrado Universidade Estadual Paulista (UNESP), Botucatu, SP Livre-Docente da Disciplina de Cirurgia Vascular Departamento de Cirurgia e Ortopedia UNESP, Botucatu, SP Faculdade de Medicina de Botucatu Departamento de Cirurgia e Ortopedia, Botucatu, SP

Background and Study Aims: The current visualization of small-bowel strictures using traditional radiological methods is associated with high radiation doses and false-negative results. These methods do not always reveal small-bowel patency for solids. The aim is to assess the safety of the Given patency system and its ability to detect intestinal strictures in patients with strictures that are known or suspected radiologically. Materials and Methods: The Given patency capsule is composed of lactose, remains intact in the gastrointestinal tract for 40-100 hours post ingestion, and disintegrates thereafter. A total of 34 patients with small-bowel stricture were prospectively enrolled; 30 had a previous diagnosis of Crohn ' s disease, three had adhesion syndrome and in one ischemic enteritis was suspected. Of the patients, 15 (44.1 %) had previously undergone surgery. Following ingestion, the capsule was monitored for integrity and transit time, using a specially designed Given scanner and also radiologically. Seventeen patients had been enrolled with the intent of using the patency capsule as a preliminary test in patients with small-bowel strictures before undergoing video capsule endoscopy. Results: 30 patients (88.2 %) retrieved the capsule in the stool; it was intact in 20 (median transit time 22 hours), and disintegrated in 10 patients (median transit time 53 hours). Six patients complained of abdominal pain which disappeared within 24 hours. The scanner successfully indicated the presence of the capsule in 94% of cases. Ten patients underwent video capsule endoscopy following the patency capsule examination; in all of these the video capsule passed through the small-bowel stricture. Conclusions: This feasibility study has shown that the Given patency capsule is a safe, effective, and convenient tool for assessment of functional patency of the small bowel. It can indicate functional patency even in cases where traditional radiology indicates stricture.

Many biochemical markers have been investigated in intestinal ischemia. However, the effects of intestinal ischemia on the level of serum immunoglobulin A (IgA) has apparently not been investigated in the literature, although the gastrointestinal system is one of the main sources of serum IgA. The aim of our study was to evaluate the changes of serum IgA levels during intestinal ischemia of varying duration in rats. Group 1 (n = 5) was created for control purposes, including the detection of the baseline values and the effects of the anesthetic agents. Group 2 (n = 20) rats underwent sham laparotomy. Group 3 (n = 20) had 50% of small intestine ischemia by the strangulated obstruction model. Serum samples were obtained by cardiac puncture 1 h after anesthetic agents were given in group 1. On the other hand, serum and intestine samples were obtained at 1 (T1, n= 5), 2 (T2, n= 5), 4 (T4, n=5) and 6 (T6, n= 5) h after the operation in groups 2 and 3. The levels of serum IgA, lactic dehydrogenase (LDH) and alkaline phosphatase (ALP) were determined. Pathologic specimens were graded in a masked manner. IgA levels were abruptly decreased to 8.49 ± 1.58 mg/dl in rats with intestinal ischemia at 1 h after the operation. This decrease in serum IgA at T1 in group 3 was statistically significant compared with the control and sham-operated groups (18.80 ± 1.15 mg/dl, 22.07 ± 1.54 mg/dl, respectively; P

The most important complication of intestinal malrotation is midgut volvulus because it may lead to intestinal ischaemia and necrosis. A 29-year-old male patient was admitted to the emergency department with abdominal pain. Ultrasonography (US), colour Doppler ultrasonography (CDUS), CT and barium studies were carried out. On US and CDUS, twisting of intestinal segments around the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) and alteration of the SMA-SMV relationship were detected. CT demonstrated that the small intestine was making a rotation around the SMA and SMV, which amounted to more than 360°. The upper gastrointestinal barium series revealed a corkscrew appearance of the duodenum and proximal jejunum, which is a pathognomonic finding of midgut volvulus. Prior knowledge of characteristic imaging findings of midgut volvulus is essential in order to reach proper diagnosis and establish proper treatment before the development of intestinal ischaemia and necrosis. Copyright 2014 BMJ Publishing Group. All rights reserved.

We investigated the effect of antithrombin III on 60 min warm intestinal ischemia-reperfusion (IR) injury in rats. Sprague-Dawley rats, weighing 220-250 g, were divided into three groups: group 1 sham-operated group (no IR injury, n = 8), group 2 ischemic control group (control, Ringer's lactate infused, n = 8), group 3 Antithrombin III treated group (250 U/kg before ischemia, n = 8). Intestinal ischemia was induced in rats by occluding the superior mesenteric artery for 60 min. Malondialdehyde (MDA) levels, myeloperoxidase activity (MPO) and mucosal damage were investigated after 120 min reperfusion. Elevated MDA levels and MPO activity and severe histopathological damage were observed in the control group compared with the sham group (P < 0.05). Decreased MDA levels and MPO activity and less histopathological damage were detected in group 3 compared with the control group (P < 0.05). Accumulation of lipid peroxidation products and neutrophils in mucosal tissues were significantly inhibited by antithrombin III treatment. We conclude that treatment with antithrombin III before intestinal ischemia prevents histological damage in rats.

Gut homeostasis results from complex neuro-immune interactions aimed at triggering stereotypical and specific programs of coordinated mucosal secretion and powerful motor propulsion. A prominent role in the regulation of this highly integrated network, comprising a variety of immune/inflammatory cells and the enteric nervous system, is played by purinergic mediators. The cells of the digestive tract are literally plunged into a "biological sea" of functionally active nucleotides and nucleosides, which carry out the critical task of driving regulatory interventions on cellular functions through the activation of P1 and P2 receptors. Intensive research efforts are being made to achieve an integrated view of the purinergic system, since it is emerging that the various components of purinergic pathways (i.e., enzymes, transporters, mediators and receptors) are mutually linked entities, deputed to finely modulating the magnitude and the duration of purinergic signaling, and that alterations occurring in this balanced network could be intimately involved in the pathophysiology of several gut disorders. This review article intends to provide a critical appraisal of current knowledge on the purinergic system role in the regulation of gastrointestinal functions, considering these pathways as a whole integrated network, which is capable of finely controlling the levels of bioactive nucleotides and nucleosides in the biophase of their respective receptors. Special attention is paid to the mechanisms through which alterations in the various compartments of the purinergic system could contribute to the pathophysiology of gut disorders, and to the possibility of counteracting such dysfunctions by means of pharmacological interventions on purinergic molecular targets. © 2013 Elsevier Inc.