Females Are More Resistant to Ischemia-Reperfusion-induced Intestinal Injury Than Males: A Human Study

Luminal Delivery of Pectin-Modified Oxygen Microbubbles Mitigates Rodent Experimental Intestinal Ischemia

INTRODUCTION

Ischemic gut injury is common in the intensive care unit, impairs gut barrier function, and contributes to multiorgan dysfunction. One novel intervention to mitigate ischemic gut injury is the direct luminal delivery of oxygen microbubbles (OMB). Formulations of OMB can be modified to control the rate of oxygen delivery. This project examined whether luminal delivery of pectin-modified OMB (OMBp5) can reduce ischemic gut injury in a rodent model.

METHODS

The OMBp5 formulation was adapted to improve delivery of oxygen along the length of small intestine. Adult Sprague-Dawley rats (n = 24) were randomly allocated to three groups: sham-surgery (SS), intestinal ischemia (II), and intestinal ischemia plus luminal delivery of OMBp5 (II + O). Ischemia-reperfusion injury was induced by superior mesenteric artery occlusion for 45 min followed by reperfusion for 30 min. Outcome data included macroscopic score of mucosal injury, the histological score of gut injury, and plasma biomarkers of intestinal injury.

RESULTS

Macroscopic, microscopic data, and intestinal injury biomarker results demonstrated minimal intestinal damage in the SS group and constant damage in the II group. II + O group had a significantly improved macroscopic score throughout the gut mucosa (P = 0.04) than the II. The mean histological score of gut injury for the II + O group was significantly improved on the II group (P ≤ 0.01) in the proximal intestine only, within 30 cm of delivery. No differences were observed in plasma biomarkers of intestinal injury following OMBp5 treatment.

CONCLUSIONS

This proof-of-concept study has demonstrated that luminal OMBp5 decreases ischemic injury to the proximal small intestine. There is a need to improve oxygen delivery over the full length of the intestine. These findings support further studies with clinically relevant end points, such as systemic inflammation and vital organ dysfunction.

Gastrointestinal cell injury and perceived symptoms after running the Boston Marathon

Gastrointestinal (GI) disturbances are a prevalent cause of marathon related complaints, and in extreme cases can promote life-threatening conditions such as exertional heat stroke. Our aim was to study intestinal cell injury [via intestinal fatty acid binding protein (I-FABP)] and perceived GI distress symptoms among marathon runners. We also examined potential risk factors (e.g., inadequate sleep) that could exacerbate GI disturbances in healthy, trained endurance runners. This was a parallel mixed-methods study design. 2019 Boston Marathon participants were recruited via email and subjects completed surveys before the race describing demographics and training history. Participants completed a GI questionnaire to assess presence and severity of symptoms, a survey regarding risk factors (e.g., recent illness, medications) that could promote GI disturbances, and provided a urine sample at three time points (immediately pre-race, post-race, and 24-h post-race). Due to weather, blood samples were only collected immediately and 24-h post-race. A total of 40 runners (males: n = 19, age = 44.9 ± 10.8 years; females: n = 21, age = 44.8 ± 10.6 years) completed this study. I-FABP significantly decreased from post-race (3367.5 ± 2633.5 pg/mL) to 24-h post-race (1657.3 ± 950.7 pg/mL, t (39) = -4.228, p < .001, d = -.669). There was a significant difference in overall GI symptom scores across the three time points (F (2, 39) = 41.37, p < .001). The highest average score occurred post-race (.84 ± .68), compared to pre-race (.09 ± .12) and 24-h post-race (.44 ± .28). Post-race I-FABP (r = .31, p = .048) and post-race urine specific gravity (r = .33, p = .041) were significantly correlated with post-race GI symptom scores. Our study provides further support to the individualized nature of GI disturbances, with participants experiencing a wide range of risk factors that can influence the extent of GI damage and perceived symptoms during and after exercise.

Should primary anastomosis be considered more? A retrospective analysis of anastomotic complications in young children

Objective

Little is known about intestinal anastomotic leakage and stenosis in young children (≤3 years of age). The purpose of this study is to answer the following questions: (1) what is the incidence of anastomotic stenosis and leakage in infants? (2) which surgical diseases entail the highest incidence of anastomotic stenosis and leakage? (3) what are perioperative factors associated with anastomotic stenosis and leakage?

Methods

Patients who underwent an intestinal anastomosis during primary abdominal surgery in our tertiary referral centre between 1998 and 2018 were retrospectively included. Both general incidence and incidence per disease of anastomotic complications were determined. Technical risk factors (location and type of anastomosis, mode of suturing, and suture resorption time) were evaluated by multivariate Cox regression for anastomotic stenosis. Gender and American Society of Anaesthesiology (ASA) score of ≥III were evaluated by χ2 test for anastomotic leakage.

Results

In total, 477 patients underwent an anastomosis. The most prominent diseases are intestinal atresia (30%), Hirschsprung's disease (29%), and necrotizing enterocolitis (14%). Anastomotic stenosis developed in 7% (34/468) of the patients with highest occurrence in necrotizing enterocolitis (14%, 9/65). Colonic anastomosis was associated with an increased risk of anastomotic stenosis (hazard ratio (HR) =3.6, 95% CI 1.8 to 7.5). No technical features (type of anastomosis, suture resorption time and mode of suturing) were significantly associated with stenosis development. Anastomotic leakage developed in 5% (22/477) of the patients, with the highest occurrence in patients with intestinal atresia (6%, 9/143). An ASA score of ≥III (p=0.03) and male gender (p=0.03) were significantly associated with anastomotic leakage.

Conclusions

Both anastomotic stenosis and leakage are major surgical complications. Identifying more patient specific factors can result in better treatment selection, which should not solely be based on the type of disease.

Biomodified Extracellular Vesicles Remodel the Intestinal Microenvironment to Overcome Radiation Enteritis

Ionizing radiation (IR) is associated with the occurrence of enteritis, and protecting the whole intestine from radiation-induced gut injury remains an unmet clinical need. Circulating extracellular vesicles (EVs) are proven to be vital factors in the establishment of tissue and cell microenvironments. In this study, we aimed to investigate a radioprotective strategy mediated by small EVs (exosomes) in the context of irradiation-induced intestinal injury. We found that exosomes derived from donor mice exposed to total body irradiation (TBI) could protect recipient mice against TBI-induced lethality and alleviate radiation-induced gastrointestinal (GI) tract toxicity. To enhance the protective effect of EVs, profilings of mouse and human exosomal microRNAs (miRNAs) were performed to identify the functional molecule in exosomes. We found that miRNA-142-5p was highly expressed in exosomes from both donor mice exposed to TBI and patients after radiotherapy (RT). Moreover, miR-142 protected intestinal epithelial cells from irradiation-induced apoptosis and death and mediated EV protection against radiation enteritis by ameliorating the intestinal microenvironment. Then, biomodification of EVs was accomplished via enhancing miR-142 expression and intestinal specificity of exosomes, and thus improved EV-mediated protection from radiation enteritis. Our findings provide an effective approach for protecting against GI syndrome in people exposed to irradiation.

Bioinformatic Analysis of lncRNA Mediated CeRNA Network in Intestinal Ischemia/Reperfusion Injury

INTRODUCTION

Recently, accumulating studies have reported the roles of competitive endogenous RNA (ceRNA) networks in ischemia/reperfusion (I/R) injury in several organs, including the liver, kidney, heart, brain, and intestine. However, the functions and mechanisms of long noncoding RNAs (lncRNAs)-which serve as ceRNA networks in intestinal I/R injury-remain elusive.

METHODS

RNA expression data were retrieved from the National Center for Biotechnology Information-Gene Expression Omnibus database. Differentially expressed microRNAs (miRNAs) (miDEGs) were explored between the sham and intestinal I/R injury samples. Next, targeted lncRNAs and messenger RNAs in the database were matched based on miDEGs. Hub ceRNA networks were constructed and visualized via Cytoscape. Intersection analysis was performed to screen mDEGs between two datasets. Finally, the vital nodes of the ceRNA networks were validated by quantitative PCR.

RESULTS

A total of 189 miDEGs were identified. Forty miRNAs were found to be associated with 240 predicted target genes from miRWalk 3.0. The ceRNA network was constructed with 10 miRNAs, including the 1700020114Rik/mmu-miR-7a-5p/Klf4 axis. Furthermore, the expression of lncRNA 1700020114Rik (P < 0.05) and messenger RNA Klf4 (P < 0.01) was markedly decreased in mouse models of intestinal I/R injury, whereas the expression level of mmu-miR-7a-5p was significantly increased (P < 0.05).

CONCLUSIONS

The results provide novel insights into the molecular mechanism of ceRNA networks in intestinal I/R injury and highlight the potential of the 170002700020114Rik/mmu-miR-7a-5p/Klf4 axis in the prevention and treatment of intestinal I/R injury.

H151, A SMALL MOLECULE INHIBITOR OF STING AS A NOVEL THERAPEUTIC IN INTESTINAL ISCHEMIA-REPERFUSION INJURY

BACKGROUND

Intestinal ischemia-reperfusion (I/R) injury is a severe disease associated with high mortality. Stimulator of interferon genes (STING) is an intracellular protein that is activated by cytosolic DNA and is implicated in I/R injury, resulting in transcription of type I interferons (IFN-α and IFN-β) and other proinflammatory molecules. Extracellular cold-inducible RNA-binding protein (eCIRP), a damage-associated molecular pattern, induces STING activation. H151 is a small molecule inhibitor of STING that has not yet been studied as a potential therapeutic. We hypothesize that H151 reduces inflammation, tissue injury, and mortality after intestinal I/R. Methods: In vitro, RAW264.7 cells were pretreated with H151 then stimulated with recombinant murine (rm) CIRP, and IFN-β levels in the culture supernatant were measured at 24 hours after stimulation. In vivo, male C57BL/6 mice were subjected to 60-minute intestinal ischemia via superior mesenteric artery occlusion. At the time of reperfusion, mice were intraperitoneally instilled with H151 (10 mg/kg BW) or 10% Tween-80 in PBS (vehicle). Four hours after reperfusion, the small intestines, lungs, and serum were collected for analysis. Mice were monitored for 24 hours after intestinal I/R to assess survival. Results: In vitro, H151 reduced rmCIRP-induced IFN-β levels in a dose-dependent manner. In vivo, intestinal levels of pIRF3 were increased after intestinal I/R and decreased after H151 treatment. There was an increase in serum levels of tissue injury markers (lactate dehydrogenase, aspartate aminotransferase) and cytokine levels (interleukin 1β, interleukin 6) after intestinal I/R, and these levels were decreased after H151 treatment. Ischemia-reperfusion-induced intestinal and lung injury and inflammation were significantly reduced after H151 treatment, as evaluated by histopathologic assessment, measurement of cell death, chemokine expression, neutrophil infiltration, and myeloperoxidase activity. Finally, H151 improved the survival rate from 41% to 81% after intestinal I/R. Conclusions: H151, a novel STING inhibitor, attenuates the inflammatory response and reduces tissue injury and mortality in a murine model of intestinal I/R. H151 shows promise as a potential therapeutic in the treatment of this disease.

Estradiol Ameliorates Acute Kidney Ischemia-Reperfusion Injury by Inhibiting the TGF-βRI-SMAD Pathway

Renal ischemia–reperfusion injury (IRI) is less extensive in females than males in both animals and humans; however, this protection diminishes after menopause, suggesting that estrogen plays a pivotal role in IRI, but the underlying mechanism remains largely unknown. Our study found that 45 min of warm ischemia was sufficient to induce significant pathological changes without causing death in model animals. Compared with male rats, female rats exhibited less extensive apoptosis, kidney injury, and fibrosis; these effects were worsened in ovariectomized (OVX) rats and ameliorated upon estradiol (E₂) supplementation. Furthermore, the levels of TGF-βRI, but not TGF-βRII or TGF-β1, were significantly increased in OVX rats, accompanied by phosphorylated SMAD2/3 activation. Interestingly, the alteration trend of the nuclear ERα level was opposite that of TGF-βRI. Furthermore, dual luciferase reporter and chromatin immunoprecipitation assays showed that ERα could bind to the promoter region of TGF-βRI and negatively regulate its mRNA expression. Moreover, an in vitro study using NRK-52E cells showed that ERα knockdown blocked E₂-mediated protection, while TGF-βRI knockdown protected cells against hypoxic insult. The findings of this study suggest that renal IRI is closely related to the TGF-βRI-SMAD pathway in females and that E₂ exert its protective effect via the ERα-mediated transcriptional inhibition of TGF-βRI expression.

Acute alcohol consumption increases systemic endotoxin bioactivity for days in healthy volunteers-with reduced intestinal barrier loss in female

OBJECTIVE

Trauma is the most common cause of death among young adults. Alcohol intoxication plays a significant role as a cause of accidents and as a potent immunomodulator of the post-traumatic response to tissue injury. Polytraumatized patients are frequently at risk to developing infectious complications, which may be aggravated by alcohol-induced immunosuppression. Systemic levels of integral proteins of the gastrointestinal tract such as syndecan-1 or intestinal fatty acid binding proteins (FABP-I) reflect the intestinal barrier function. The exact impact of acute alcohol intoxication on the barrier function and endotoxin bioactivity have not been clarified yet.

METHODS

22 healthy volunteers received a precisely defined amount of alcohol (whiskey-cola) every 20 min over a period of 4 h to reach the calculated blood alcohol concentration (BAC) of 1‰. Blood samples were taken before alcohol drinking as a control, and after 2, 4, 6, 24 and 48 h after beginning with alcohol consumption. In addition, urine samples were collected. Intestinal permeability was determined by serum and urine values of FABP-I, syndecan-1, and soluble (s)CD14 as a marker for the endotoxin translocation via the intestinal barrier by ELISA. BAC was determined.

RESULTS

Systemic FABP-I was significantly reduced 2 h after the onset of alcohol drinking, and remained decreased after 4 h. However, at 6 h, FABP-I significantly elevated compared to previous measurements as well as to controls (p < 0.05). Systemic sCD14 was significantly elevated after 6, 24 and 48 h after the onset of alcohol consumption (p < 0.05). Systemic FABP-I at 2 h after drinking significantly correlated with the sCD14 concentration after 24 h indicating an enhanced systemic LPS bioactivity. Women showed significantly lower levels of syndecan-1 in serum and urine and urine for all time points until 6 h and lower FABP-I in the serum after 2 h.

CONCLUSIONS

Even relative low amounts of alcohol affect the immune system of healthy volunteers, although these changes appear minor in women. A potential damage to the intestinal barrier and presumed enhanced systemic endotoxin bioactivity after acute alcohol consumption is proposed, which represents a continuous immunological challenge for the organism and should be considered for the following days after drinking.

HMGB1 signaling-regulated endoplasmic reticulum stress mediates intestinal ischemia/reperfusion-induced acute renal damage

BACKGROUND

Ischemia/reperfusion of the intestine often leads to distant organ injury, but the mechanism of intestinal ischemia/reperfusion-induced renal dysfunction is still not clear. The present study aimed to investigate the mechanisms of acute renal damage after intestinal ischemia/reperfusion challenge and explore the role of released high-mobility group box-1 in this process.

METHODS

Intestinal ischemia/reperfusion was induced in male Sprague-Dawley rats by clamping the superior mesenteric artery for 1.5 hours. At different reperfusion time points, anti-high-mobility group box-1 neutralizing antibodies or ethyl pyruvate were administered to neutralize or inhibit circulating high-mobility group box-1, respectively.

RESULTS

Significant kidney injury was observed after 6 hours of intestinal reperfusion, as indicated by increased serum levels of urea nitrogen and creatinine, increased expression of neutrophil gelatinase-associated lipocalin, interleukin-6, and MIP-2, and enhanced cell apoptosis, as indicated by cleaved caspase 3 levels in renal tissues. The levels of phosphorylated eIF2ɑ, activating transcription factor 4, and C/EBP-homologous protein (CHOP) were markedly elevated, indicating the activation of endoplasmic reticulum stress in the impaired kidney. High-mobility group box-1 translocated to cytoplasm in the intestine and serum concentrations of high-mobility group box-1 increased notably during the reperfusion phase. Both anti-high-mobility group box-1 antibodies and ethyl pyruvate treatment significantly reduced serum high-mobility group box-1 concentrations, attenuated endoplasmic reticulum stress in renal tissue and inhibited the development of renal damage. Moreover, the elevated expression of receptor for advanced glycation end products in the kidneys after intestinal ischemia/reperfusion was abrogated after high-mobility group box-1 inhibition.

CONCLUSION

These results suggested that high-mobility group box-1 signaling regulated endoplasmic reticulum stress and promoted intestinal ischemia/reperfusion-induced acute kidney injury. High-mobility group box-1 neutralization/inhibition might serve as a pharmacological intervention strategy for these pathophysiological processes.

Evaluating the safety of two human experimental intestinal ischemia reperfusion models: A retrospective observational study

Background

We developed a jejunal and colonic experimental human ischemia-reperfusion (IR) model to study pathophysiological intestinal IR mechanisms and potential new intestinal ischemia biomarkers. Our objective was to evaluate the safety of these IR models by comparing patients undergoing surgery with and without in vivo intestinal IR.

Methods

A retrospective study was performed comparing complication rates and severity, based on the Clavien-Dindo classification system, in patients undergoing pancreatoduodenectomy with (n = 10) and without (n = 20 matched controls) jejunal IR or colorectal surgery with (n = 10) and without (n = 20 matched controls) colon IR. Secondary outcome parameters were operative time, blood loss, 90-day mortality and length of hospital stay.

Results

Following pancreatic surgery, 63% of the patients experienced one or more postoperative complications. There was no significant difference in incidence or severity of complications between patients undergoing pancreatic surgery with (70%) or without (60%, P = 0.7) jejunal IR. Following colorectal surgery, 60% of the patients experienced one or more postoperative complication. Complication rate and severity were similar in patients with (50%) and without (65%, P = 0.46) colonic IR. Operative time, amount of blood loss, postoperative C-reactive protein, length of hospital stay or mortality were equal in both intervention and control groups for jejunal and colon IR.

Conclusion

This study showed that human experimental intestinal IR models are safe in patients undergoing pancreatic or colorectal surgery.

Fetuin-A exerts a protective effect against experimentally induced intestinal ischemia/reperfusion by suppressing autophagic cell death

Intestinal tissue is highly susceptible to ischemia/reperfusion injury in many hazardous health conditions. The anti-inflammatory and antioxidant glycoprotein fetuin-A showed efficacy in cerebral ischemic injury; however, its protective role against intestinal ischemia/reperfusion remains elusive. Therefore, this study investigated the protective role of fetuin-A supplementation against intestinal structural changes and dysfunction in a rat model of intestinal ischemia/reperfusion. We equally divided 72 male rats into control, sham, ischemia/reperfusion, and fetuin-A-pretreated ischemia/reperfusion (100 mg/kg/day fetuin-A intraperitoneally for three days prior to surgery and a third dose 1 h prior to the experiment) groups. After 2 h of reperfusion, the jejunum was dissected and examined for spontaneous contractility. A jejunal homogenate was used to assess inflammatory and oxidative stress enzymes. Staining of histological sections was carried out with hematoxylin, eosin and Masson's trichrome stain for evaluation. Immunohistochemistry was performed to detect autophagy proteins beclin-1, LC3, and p62. This study found that fetuin-A significantly improved ischemia/reperfusion-induced mucosal injury by reducing the percentage of areas of collagen deposition, increasing the amplitude of spontaneous contraction, decreasing inflammation and oxidative stress, and upregulating p62 expression, which was accompanied by beclin-1 and LC3 downregulation. Our findings suggest that fetuin-A treatment can prevent ischemia/reperfusion-induced jejunal structural and functional changes by increasing antioxidant activity and regulating autophagy disturbances observed in the ischemia/reperfusion rat model. Furthermore, fetuin-A may provide a protective influence against intestinal ischemia/reperfusion complications.

Targeting the Endothelium to Achieve Cardioprotection

Despite considerable improvements in the treatment of myocardial infarction, it is still a highly prevalent disease worldwide. Novel therapeutic strategies to limit infarct size are required to protect myocardial function and thus, avoid heart failure progression. Cardioprotection is a research topic with significant achievements in the context of basic science. However, translation of the beneficial effects of protective approaches from bench to bedside has proven difficult. Therefore, there is still an unmet need to study new avenues leading to protecting the myocardium against infarction. In line with this, the endothelium is an essential component of the cardiovascular system with multiple therapeutic targets with cardioprotective potential. Endothelial cells are the most abundant non-myocyte cell type in the heart and are key players in cardiovascular physiology and pathophysiology. These cells can regulate vascular tone, angiogenesis, hemostasis, and inflammation. Accordingly, endothelial dysfunction plays a fundamental role in cardiovascular diseases, which may ultimately lead to myocardial infarction. The endothelium is of paramount importance to protect the myocardium from ischemia/reperfusion injury via conditioning strategies or cardioprotective drugs. This review will provide updated information on the most promising therapeutic agents and protective approaches targeting endothelial cells in the context of myocardial infarction.

Inhibition of a triggering receptor expressed on myeloid cells-1 (TREM-1) with an extracellular cold-inducible RNA-binding protein (eCIRP)-derived peptide protects mice from intestinal ischemia-reperfusion injury

BACKGROUND

Intestinal ischemia-reperfusion injury results in morbidity and mortality from both local injury and systemic inflammation and acute lung injury. Extracellular cold-inducible RNA-binding protein is a damage associated molecular pattern that fuels systemic inflammation and potentiates acute lung injury. We recently discovered a triggering receptor expressed on myeloid cells-1 serves as a novel receptor for extracellular cold-inducible RNA-binding protein. We developed a 7-aa peptide, named M3, derived from the cold-inducible RNA-binding protein, which interferes with cold-inducible RNA-binding protein's binding to a triggering receptor expressed on myeloid cells-1. Here, we hypothesized that M3 protects mice against intestinal ischemia-reperfusion injury.

METHODS

Intestinal ischemia was induced in C57BL/6 mice via clamping of the superior mesenteric artery for 60 minutes. At reperfusion, mice were treated intraperitoneally with M3 (10 mg/kg body weight) or normal saline vehicle. Mice were killed 4 hours after reperfusion and blood and lungs were collected for various analysis. A 24-hours survival after intestinal ischemia-reperfusion was assessed.

RESULTS

Serum levels of organ injury markers aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and lactate were increased with intestinal ischemia-reperfusion, while treatment with M3 significantly decreased their levels. Serum, intestinal, and lung levels of proinflammatory cytokines and chemokines were also increased by intestinal ischemia-reperfusion, and treatment with M3 significantly reduced these values. Intestinal ischemia-reperfusion caused significant histological intestinal and lung injuries, which were mitigated by M3. Treatment with M3 improved the survival from 40% to 80% after intestinal ischemia-reperfusion.

CONCLUSION

Inhibition of triggering receptor expressed on myeloid cells-1 by an extracellular cold-inducible RNA-binding protein-derived small peptide (M3) decreased inflammation, reduced lung injury, and improved survival in intestinal ischemia-reperfusion injury. Thus, blocking the extracellular cold-inducible RNA-binding protein-triggering receptor expressed on myeloid cells-1 interaction is a promising therapeutic avenue for mitigating intestinal ischemia-reperfusion injury.

Sildenafil as a Rescue Agent Following Intestinal Ischemia and Reperfusion Injury

BACKGROUND

Acute mesenteric ischemia carries a significant morbidity. Measures to improve blood flow parameters to the intestine may ameliorate the disease. Sildenafil, a phosphodiesterase 5 inhibitor, increases cyclic guanosine monophosphate and has been shown to prevent the effects of ischemia when given before injury. However, its effects as a rescue agent have not been established. We therefore hypothesized that sildenafil, when given as a rescue agent for intestinal ischemia, would improve mesenteric perfusion, limit intestinal epithelial injury, and decrease intestinal leukocyte chemoattractants.

METHODS

Eight to 12 wk-old-male C57BL/6J mice underwent laparotomy and temporary occlusion of the superior mesenteric artery for 60 min. Following ischemia, reperfusion was permitted, and before closing the abdomen, sildenafil was injected intraperitoneally in a variety of concentrations. After 24 h, reperfusion was reassessed. Animals were euthanized and intestines evaluated for histologic injury and leukocyte chemoattractants.

RESULTS

Postischemic administration of sildenafil did not improve mesenteric perfusion following intestinal ischemia and reperfusion injury. However, sildenafil did improve histologic injury scores in dose ranges of 0.01 to 10 mg/kg. No difference was noted in histological injury with 100 mg/kg dose, and all members of the 1000 mg/kg group died within 24 h of injury. Epithelial protection was not facilitated by the leukocyte chemoattractants Regulated on Activation, Normal T Cell Expressed, and Secreted, macrophage inflammatory protein 1 alpha, monocyte chemoattractant protein, neutrophil activating protein, or granulocyte colony stimulating factor.

CONCLUSIONS

Administration of sildenafil following intestinal ischemia may limit intestinal mucosal injury but does not appear to alter mesenteric perfusion or leukocyte chemoattractant influx. TYPE: Basic science.

LEVEL OF EVIDENCE

N/A.