Intestinal Manipulation Research Articles

Postoperative Ileus Murine Model.

Most patients experience postoperative ileus (POI) after surgery, which is associated with increased morbidity, mortality, and hospitalization time. POI is a consequence of mechanical damage during surgery, resulting in disruption of motility in the gastrointestinal tract. The mechanisms of POI are related to aberrant neuronal sensitivity, impaired epithelial barrier function, and increased local inflammation. However, the details remain enigmatic. Therefore, experimental murine models are crucial for elucidating the pathophysiology and mechanism of POI injury and for the development of novel therapies. Here, we introduce a murine model of POI generated via intestinal manipulation (IM) that is similar to clinical surgery; this is achieved by mechanical damage to the small intestine by massaging the abdomen 1-3 times with a cotton swab. IM delayed gastrointestinal transit 24 h after surgery, as assessed by FITC-dextran gavage and fluorescence detection of the segmental digestive tract. Moreover, tissue swelling of the submucosa and immune cell infiltration were investigated by hematoxylin and eosin staining and flow cytometry. Proper pressure of the IM and a hyperemic effect on the intestine are critical for the procedure. This murine model of POI can be utilized to study the mechanisms of intestinal damage and recovery after abdominal surgery.

Electroacupuncture treatment improves postoperative ileus by inhibiting the Th1 cell-mediated inflammatory response through the vagus nerve.

Electroacupuncture (EA) has been reported to improve intestinal motility in mice with postoperative ileus (POI). Previous studies, however, have yielded heterogeneous results regarding the effect of EA on POI. Herein, a POI mouse model was constructed by intestinal manipulation. To evaluate the effect of EA treatment on colonic transit, the levels of inflammatory markers (macrophage inflammatory protein (MIP)-1α, interleukin (IL)-1β, IL-6, monocyte chemotactic protein (MCP)-1 and intercellular adhesion molecule (ICAM)-1) were detected by enzyme-linked immunosorbent assay (ELISA); immune cell infiltration was detected by immunohistochemical staining of myeloperoxidase (MPO), ectodysplasin (ED)-1 and ED-2, and the percentage of CD4+ interferon (IFN)-γ+ Th1 cells and IFN-γ secretion levels were determined. Activated Th1 cells and pentoxifylline, a cell differentiation inhibitor, were used to assess the role of Th1 cells in EA treatment of POI. Neostigmine administration and unilateral vagotomy were performed to confirm whether the effects of EA treatment on Th1 cells were mediated by the vagus nerve (VN). The results revealed that EA treatment at ST36 improved POI, as indicated by a decreased level of inflammatory-related markers and immune cell infiltration and shortened colonic transit time. The activated Th1 cells abolished the effects of EA treatment on POI. The effects of EA treatment on POI were enhanced by stimulation of the VN along with a decreased level of Th1 cells, but these effects were abolished by vagotomy along with an increased percentage of Th1 cells; this result indicates that the VN mediates the role of Th1 cells in the effects of EA treatment of POI. Our findings showed that the effects of EA treatment of POI were mainly mediated by Th1 cells through the stimulation of the VN and inhibition of the inflammatory response.

Electroacupuncture alleviates intestinal inflammation via a distinct neuro-immune signal pathway in the treatment of postoperative ileus

BackgroundThe induction of intestinal inflammation as a result of abdominal surgery is an essential factor in postoperative ileus (POI) development. Electroacupuncture (EA) at ST36 has been demonstrated to relieve intestinal inflammation and restore gastrointestinal dysmotility in POI. This study aims to elucidate the neuroimmune pathway involved in the anti-inflammatory properties of EA in POI. MethodsAfter intestinal manipulation (IM) was performed to induce POI, intestinal inflammation and motility were assessed 24 h post-IM, by evaluating gastrointestinal transit (GIT), cytokines expression, and leukocyte infiltration. Experimental surgery, pharmacological intervention, and genetic knockout mice were used to elucidate the neuroimmune mechanisms of EA. ResultsEA at ST36 significantly improved GIT and reduced the expression of pro-inflammatory cytokines and leukocyte infiltration in the intestinal muscularis following IM in mice. The anti-inflammatory effectiveness of EA treatment was abolished by sub-diaphragmatic vagotomy, whereas splenectomy did not hinder the anti-inflammatory benefits of EA treatment. The hexamethonium chloride (HEX) administration contributes to a notable reduction in the EA capacity to suppress inflammation and enhance motility dysfunction, and EA is ineffective in α7 nicotinic acetylcholine receptor (α7nAChR) knockout mice. ConclusionsEA at ST36 prevents intestinal inflammation and dysmotility through a neural circuit that requires vagal innervation but is independent of the spleen. Further findings revealed that the process involves enteric neurons mediating the vagal signal and requires the presence of α7nAChR. These findings suggest that utilizing EA at ST36 may represent a possible therapeutic approach for POI and other immune-related gastrointestinal diseases.

Exploring the chemical components of Kuanchang-Shu granule and its protective effects of postoperative ileus in rats by regulating AKT/HSP90AA1/eNOS pathway

BackgroundPostoperative ileus (POI) is a common obstruction of intestinal content passage caused by almost all abdominal operations that seriously strokes the quality of life of patients. Kuanchang-Shu granule (KCSG), a classic modified prescription based on “Da-Cheng-Qi Decoction”, has obtained satisfactory efficacy in the clinical therapeutics of POI. However, its material basis and holistic molecular mechanism against POI have not been revealed.MethodsThe chemical ingredients of KCSG were first characterized by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS). Subsequently, an integration strategy of the network pharmacology and molecular docking based on above identified ingredients was performed to unveil the potential targets involved in the treatment of KCSG on POI. Finally, intestinal manipulation induced rat POI model was constructed to verify the efficacy and predicted mechanism of KCSG against POI.ResultsIn total, 246 ingredients mainly including organic acids, flavonoids, quinones, alkaloids, terpenoids, phenylpropanoids and phenols were identified. 41 essential ingredients, 24 crucial targets as well as 15 relevant signaling pathways were acquired based on network pharmacology analysis. Pharmacodynamic research showed that KCSG treatment could protect intestinal histological damage, promote the recovery of measurement of gastrointestinal transit disorder and inhibit the secretion of myeloperoxidase in the distal ileum tissues. The up-regulated expression of p-AKT and down-regulated expression of p-eNOS and HSP9OAA1 predicted by molecular docking and validated by western blotting showed that AKT/eNOS/HSP90AA1 pathway may be one of the crucial mechanisms that mediates the protective effect of KCSG.

β-adrenergic signaling triggers enteric glial reactivity and acute enteric gliosis during surgery

BackgroundEnteric glia contribute to the pathophysiology of various intestinal immune-driven diseases, such as postoperative ileus (POI), a motility disorder and common complication after abdominal surgery. Enteric gliosis of the intestinal muscularis externa (ME) has been identified as part of POI development. However, the glia-restricted responses and activation mechanisms are poorly understood. The sympathetic nervous system becomes rapidly activated by abdominal surgery. It modulates intestinal immunity, innervates all intestinal layers, and directly interfaces with enteric glia. We hypothesized that sympathetic innervation controls enteric glia reactivity in response to surgical trauma.MethodsSox10iCreERT2/Rpl22HA/+ mice were subjected to a mouse model of laparotomy or intestinal manipulation to induce POI. Histological, protein, and transcriptomic analyses were performed to analyze glia-specific responses. Interactions between the sympathetic nervous system and enteric glia were studied in mice chemically depleted of TH+ sympathetic neurons and glial-restricted Sox10iCreERT2/JellyOPfl/+/Rpl22HA/+ mice, allowing optogenetic stimulation of β-adrenergic downstream signaling and glial-specific transcriptome analyses. A laparotomy model was used to study the effect of sympathetic signaling on enteric glia in the absence of intestinal manipulation. Mechanistic studies included adrenergic receptor expression profiling in vivo and in vitro and adrenergic agonism treatments of primary enteric glial cell cultures to elucidate the role of sympathetic signaling in acute enteric gliosis and POI.ResultsWith ~ 4000 differentially expressed genes, the most substantial enteric glia response occurs early after intestinal manipulation. During POI, enteric glia switch into a reactive state and continuously shape their microenvironment by releasing inflammatory and migratory factors. Sympathetic denervation reduced the inflammatory response of enteric glia in the early postoperative phase. Optogenetic and pharmacological stimulation of β-adrenergic downstream signaling triggered enteric glial reactivity. Finally, distinct adrenergic agonists revealed β-1/2 adrenoceptors as the molecular targets of sympathetic–driven enteric glial reactivity.ConclusionsEnteric glia act as early responders during post-traumatic intestinal injury and inflammation. Intact sympathetic innervation and active β-adrenergic receptor signaling in enteric glia is a trigger of the immediate glial postoperative inflammatory response. With immune-activating cues originating from the sympathetic nervous system as early as the initial surgical incision, adrenergic signaling in enteric glia presents a promising target for preventing POI development.

Involvement of iNOS-induced reactive enteric glia cells in gastrointestinal motility disorders of postoperative Ileus mice

Postoperative ileus (POI) is the cessation or reduction of gastrointestinal (GI) motility after surgery. Reactive enteric glial cells (EGCs) are critical for maintaining bowel function. However, the triggering mechanisms and downstream effects of reactive EGCs in POI were poorly understood. The goal of this current study was to investigate whether the inducible nitric oxide synthase (iNOS)-driven reactive EGCs participated in GI motility disorders and mechanisms underlying altered GI motility in POI. Intestinal manipulation (IM)-induced POI mice and iNOS−/− mice were used in the study. Longitudinal muscle and myenteric plexuses (LMMPs) from the distal small intestine were stained by immunofluorescence. Our results found that the GI motility disorders occurred in the IM-induced POI mice, and reactive EGCs were observed in LMMPs. Glial metabolic inhibitor gliotoxin fluorocitrate (FC) treatment or iNOS gene knockout attenuated GI motility dysfunction. In addition, we also found that FC treatment or iNOS gene knockout significantly inhibited the fluorescence intensity macrophage colony-stimulating factor (M-CSF), which reduced M2 phenotype macrophages activation in LMMPs of IM-induced POI mice. Our findings demonstrated that iNOS-driven reactive EGCs played a key role and were tightly linked to the MMs homeostasis in the POI mice. EGCs are emerging as a new frontier in neurogastroenterology and a potential therapeutic target.

Molecular mechanisms of postoperative ileus following gastrointestinal surgery

Abstract Postoperative ileus (POI) is characterized by a transient cessation of gastrointestinal (GI) motility and is a common complication following surgery, especially GI surgery. The mechanism of POI is complex and multifactorial and is considered to be mainly related to sympathetic neural reflexes, activation of gut opioid receptors, and inflammatory reactions. Incision of the skin and muscle, as well as the opening of the peritoneal cavity cause a neurological reflex arc involving the spinal loop with afferent splanchnic nerves synapsing in the spinal cord, activating efferent traveling back to the gut, which constitutes the first phase of POI. Once the stimulation by intestinal manipulation, traction of the abdomen for laparotomy, and distension for laparoscopy have been completed, accompanied by abdominal closure, activation of these signal pathways will terminate. As the neurological phase subsides, numerous immune cell infiltration, including mast cells, monocytes, and macrophages, appear in the intestine, which promotes the secretion of pro-inflammatory molecules and the induction of intestinal inflammation. The resolution of inflammation is the last pathological phase of POI, which is mainly mediated by the macrophage polarization and vagal system. This review highlights the current knowledge of molecular mechanisms of POI after elective intestinal surgery, which may offer the possibility and direction for effective management and treatment plans to reduce the burden of POI.

Damage-induced NAD release activates intestinal CD4+ and CD8+ T cell via P2X7R signaling

BackgroundPostoperative ileus (POI) is characterized by the activation of inflammation triggered by tissue damage. Damage-associated molecular patterns (DAMPs) reportedly induce local inflammation after injury. However, the impact of DAMPs on intestinal resident lymphocytes during POI remains poorly elucidated. MethodsPOI in mice was induced via intestinal manipulation (IM). The concentration of nicotinamide adenine dinucleotide (NAD) was detected after IM. The gastrointestinal motility of the mice was assessed after IM or NAD injection. Cytokine production and calcium influx in T cells were investigated after NAD stimulation using flow cytometry. ResultsThe concentration of extracellular NAD significantly increased after IM administration, and NAD directly impaired gastrointestinal motility. Intraperitoneal injection of NAD promoted the expression of TNF-α in intestinal CD8+ and CD4+ T cells, but only IFN-γ production by CD8+ T cells was significantly promoted by NAD injection. Granzyme B production in CD8+ and CD4+ T cells decreased after administration. Concordantly, the same results were observed in NAD stimulation of intestinal CD3+ T cells in vitro. Blocking the P2X7R-related membrane enzyme ART2.2 significantly diminished the pro-inflammatory effect of NAD. ConclusionIM includes the release of NAD derived from damaged tissues, consequently promoting pro-inflammatory cytokine production in intestinal CD4+ and CD8+ T lymphocytes. NAD-induced intestinal T cells activation may be associated with POI progression in the mouse.

Fuzapladib reduces postsurgical inflammation in the intestinal muscularis externa.

Postoperative ileus (POI) is a surgical complication that induces emesis and anorexia. Fuzapladib (FUZ), an inhibitor of leukocyte-function-associated antigen type 1 (LFA-1) activation, a leukocyte adhesion molecule, exerts anti-inflammatory effects by inhibiting leukocyte migration into the inflammatory site. In this study, we examined the prophylactic impact of FUZ on POI in a mouse model. POI model mice were generated by intestinal manipulation, and the effect of FUZ on intestinal transit and the infiltration of inflammatory cells into the ileal muscularis externa was assessed. The increased number of macrophages was significantly suppressed by FUZ, whereas the infiltration of neutrophils into the ileal muscularis externa was not sufficiently inhibited in the POI model mice. Additionally, FUZ did not ameliorate delayed gastrointestinal transit in POI model mice. In conclusion, our results suggest that FUZ does not improve delayed gastrointestinal transit but partially inhibits inflammation in the ileal muscularis externa in POI model mice. FUZ may be a potential anti-inflammatory agent for the management of post-surgical inflammation.

Elucidation of a Novel Mechanism of Perioperative and Postoperative Ileus: Microvascular Leak of Serum Immunoglobulins Directly Activates Inhibitory Nitrergic Neuromuscular Transmission, Causing Ileus

INTRODUCTION: Postoperative ileus delays enteral feeding, increases morbidity, prolongs hospitalization, and increases cost. Prevailing hypotheses are that anesthesia plays a major role in perioperative ileus and inflammation causes postoperative ileus. However, the direct causative mechanism of ileus is still unknown. Our goal was to delineate the components of an abdominal operative procedure on ileus and elucidate a major causative mechanism. METHODS: Five groups of C57Bl/6 were used: control, anesthesia, incision, laparotomy, and intestinal manipulation (IM), (N = 4 each). Gastrointestinal transit (GIT) with geometric center (GC) calculation was assessed immediately after resuscitation and after 24 hours. IM consisted of “running the bowel”. Circular muscle contractility assessed using an organ bath. Jejunal and colonic segments with fluorophore illuminated microvasculature were imaged by confocal microscopy. RESULTS: GIT for each component of the immediate perioperative ileus response was: anesthesia 25.7%, incision 13.6%, laparotomy 15.2% and IM 45.5%. Anesthesia decreased GIT, which rapidly waned. Only IM 24-hour postoperative GIT remained delayed (GC = 4.2 ± 0.52). Contractility was only significantly suppressed in IM 24-hour group. Imaging of control jejunal and colonic segments demonstrated illuminated microvasculature fluorophore containment. Vascular leak was prominent in IM immediate and IM 24-hour groups. Intraperitoneal serum injection (250µl) caused an immediate transit delay. Jejunal and colonic muscle spontaneous contraction was significantly inhibited by 1% serum, which was blocked with L-nitro-arginine (100µM). L-protein Ig elution and exogenous IgG abolished contractions. CONCLUSION: The data demonstrate that perioperative and postoperative ileus is mechanistically caused by the microvascular leak of serum immunoglobulin triggering a nitrergic neuromuscular suppression of motility.

Treatment with the 5-Lipoxygenase Antagonist Zileuton Protects Mice from Postoperative Ileus

Introduction: Previous work of our group showed that lipoxygenase (LOX) pathways become activated upon surgical manipulation of the bowel wall and revealed a beneficial immune modulating role of the LOX-derived anti-inflammatory mediator protectin DX in postoperative ileus (POI). While we found a particular role of 12/15-LOX in the anti-inflammatory LOX action during POI, the role of 5-LOX, which produces the pro-inflammatory leukotriene B4 (LTB4), remained unknown. The purpose of this study was to investigate the role of 5-LOX within the pathogenesis of POI in a mouse model. Methods: POI was induced by intestinal manipulation (IM) of the small bowel in C57BL/6, 5-LOX−/−, and CX3CR1GFP/+. Mice were either treated with a vehicle or with the synthetic 5-LOX antagonist zileuton or were left untreated. Cellular localization of 5-LOX and LTB4 release were visualized by immunofluorescence or ELISA, respectively. POI severity was quantified by gastrointestinal transit (GIT) and leukocyte extravasation into the muscularis externa (ME) by immunohistochemistry. Results: 5-LOX expression was detected 24 h after IM within infiltrating leukocytes in the ME. LTB4 levels increased during POI in wild type but not in 5-LOX−/− after IM. POI was ameliorated in 5-LOX−/− as shown by decreased leukocyte numbers and normalized GIT. Zileuton normalized the postoperative GIT and reduced the numbers of infiltrating leukocytes into the ME. Discussion/Conclusion: Our data demonstrate that 5-LOX and its metabolite LTB4 play a crucial role in POI. Genetic deficiency of 5-LOX and pharmacological antagonism by zileuton protected mice from POI. 5-LOX antagonism might be a promising target for prevention of POI in surgical patients.

Activation of p38 mitogen-activated protein kinase pathway by lipopolysaccharide aggravates postoperative ileus in colorectal cancer patients.

Patients undergoing abdominal surgery can develop postoperative ileus (POI). Inflammation of the intestinal muscularis following intestinal manipulation may be caused by displaced bacteria or lipopolysaccharide (LPS). The aim of this study was to investigate the relationship between gut microbiota, LPS, and POI in colorectal cancer (CRC) patients and explore underlying mechanisms of LPS-triggered POI. Sixty CRC patients undergoing colorectal resection were included. Bacterial communities from fecal samples were characterized by 16S rRNA gene sequencing, and fecal LPS levels were determined by Limulus amebocyte lysate assay. Mice were used to mechanistically investigate the causal relationship between microbiota, LPS, and POI. We discovered that CRC patients who developed prolonged POI (PPOI) had a unique pro-inflammatory gut microbial composition during the perioperative period. The highest proportions of Gram-negative bacteria at the genus level were Escherichia-Shigella and Bacteroides; the abundance of Escherichia-Shigella was higher throughout the perioperative period. Fecal LPS levels were significantly higher in patients with PPOI. In mice treated with an antibiotic cocktail, intestinal muscularis inflammation and intestinal dysfunction were significantly improved. Inflammation and dysfunction were significantly reduced in mice treated with polymyxin B, but were worsened by treatment with LPS. Moreover, LPS upregulated p38 phosphorylation in mice, and treatment with an inhibitor of p38 (SB203580) significantly alleviated intestinal inflammation and dysmotility. Lipopolysaccharide increases intestinal muscularis inflammation via activation of p38 signaling, which aggravates POI. Removing bacterial sources of LPS during the perioperative period is promising for the prophylactic treatment of PPOI.

Hangekobokuto, a traditional Japanese herbal medicine, ameliorates postoperative ileus through its anti-inflammatory action.

Background/Aims: Gastroprokinetic agents are used for patients with postoperative ileus (POI), and the Japanese traditional herbal medicine daikenchuto (DKT) is one such agent used in the clinical setting. POI is caused by inflammation. DKT and rikkunshito have anti-inflammatory abilities in addition to their gastroprokinetic effects. The efficacy of Kampo formulations, including hangekobokuto (HKT), in patients with POI has been reported recently. Several authors have described the efficacy of honokiol, the primary component of Magnoliae Cortex, in HKT in mouse models of POI. We therefore analyzed the effect of HKT on POI model mice to determine the similarities in the mechanism of action between HKT and DKT. Methods: HKT was administered orally to each mouse before and after intestinal manipulation was performed on the distal ileum. The gastrointestinal transit in vivo, leukocyte infiltration, and levels of inflammatory mediators, such as cytokines and chemokines, were analyzed. Results: HKT significantly inhibited the infiltration of neutrophils and macrophages and led to the recovery of delayed intestinal transit. In addition, it significantly decreased inducible nitric oxide synthase (iNOS) as well as honokiol levels, suggesting anti-inflammatory activity. However, it did not inhibit the increase in levels of interleukin (IL)-1beta and IL-6, which are related to iNOS induction. In contrast, HKT increased levels of nerve growth factor (NGF) and suppressed those of nuclear factor-κB (NFκB), which are related to iNOS induction, suggesting the possibility of a neuronal anti-inflammatory mechanism. Conclusions: HKT exerted a POI-relieving effect similar to DKT in a murine POI model, and findings suggest that it may exert its anti-inflammatory activity through NGF.

Purinergic P2X7 receptor antagonist ameliorates intestinal inflammation in postoperative ileus.

Postoperative ileus (POI) is a postsurgical gastrointestinal motility dysfunction caused by mechanical stress to the intestine during abdominal surgery. POI leads to nausea and vomiting reduced patient quality of life, as well as high medical costs and extended hospitalization. Intestinal inflammation caused by macrophages and neutrophils is thought to be important in the mechanism of POI. Surgery-associated tissue injury and inflammation induce the release of adenosine triphosphate (ATP) from injured cells. Released ATP binds the purinergic P2X7 receptor (P2X7R) expressed on inflammatory cells, inducing the secretion of inflammatory mediators. P2X7R antagonists are thought to be important mediators of the first step in the inflammation process, and studies in chemically induced colitis models confirmed that P2X7R antagonists exhibit anti-inflammatory effects. Therefore, we hypothesized that P2X7R plays an important role in POI. POI models were generated from C57BL/6J mice. Mice were treated with P2X7R antagonist A438079 (34 mg/kg) 30 min before and 2 hr after intestinal manipulation (IM). Inflammatory cell infiltration and gastrointestinal transit were measured. A438079 ameliorated macrophage and neutrophil infiltration in the POI model. Impaired intestinal transit improved following A438079 treatment. P2X7R was expressed on both infiltrating and resident macrophages in the inflamed ileal muscle layer. The P2X7R antagonist A438079 exhibits anti-inflammatory effects via P2X7R expressed on macrophages and therefore could be a target in the treatment of POI.

Application of Gut Microbiomes in The Diagnosis and Treatment of Cancer

In this study, the gut microbiome was closely related to human health. Changes in intestinal microbial composition promoted carcinogenesis and cancer development. Specific intestinal microorganisms and their metabolites regulated host physiological functions and tumor microenvironment and significantly affected the anti-tumor treatment response and its adverse effects. Gut microbiome-based strategies have shown promising prospects in the diagnosis and treatment of cancer, and many novel intestinal microbiological manipulation strategies have emerged. At the same time, there were many challenges in transforming intestinal microecology research into clinical practice. Key words: Gut microbiome; tumor microbiome; tumor microenvironment; immunotherapy.

Técnica de ovariossalpingohisterectomia invertida em gatas: vantagens e limitações

The inverted ovariosalpingohysterectomy (OSH) technique involves initial uterine removal, followed by ovarian disinsertion. The objective of this study was to compare the inverted technique with the traditional technique, characterized by initial removal of the ovaries followed by uterine resection, for evaluating the performance of the inverted OSH technique in cats. For this, 24 healthy, female cats, aged between 7 months and 5 years, with a body condition score of up to 6 points (9-point scale), divided into two equal groups: the traditional technique (TT) and the inverted technique (IT). Procedures were performed by the same veterinarians (surgeon and their assistant) as well as semi-quantitative analysis of the techniques (questionnaire related to the ease of uterine and ovarian manipulation as well as of intestinal and urinary vesicle manipulation) and descriptive qualitative analysis (technical report with the opinion of surgeons and an external evaluator). In addition, the total surgical time and positive pain response were evaluated, indicated by the changes in vital parameters observed by the anesthesiologist during surgery. Inverted technique it promoted greater ovarian exposure, allowing uterine cranial flexion to perform the ligatures, thus facilitating their manipulation, hemostasis, and section of the pedicle. Free the uterus from its ligaments to the abdominal cavity allowed greater mobilization of the conjoint. Both techniques required short operation time (average time of 16’± 1.321’ in the IT group and 15’± 0.525’ in the TT group). The presence of algetic stimulus was similar in the techniques, three animals in each group suffered analgesic rescue.

Extrahepatic Surgery in Cirrhosis Significantly Increases Portal Pressure in Preclinical Animal Models.

Background: Liver cirrhosis is a relevant comorbidity with increasing prevalence. Postoperative decompensation and development of complications in patients with cirrhosis remains a frequent clinical problem. Surgery has been discussed as a precipitating event for decompensation and complications of cirrhosis, but the underlying pathomechanisms are still obscure. The aim of this study was to analyze the role of abdominal extrahepatic surgery in cirrhosis on portal pressure and fibrosis in a preclinical model.Methods: Compensated liver cirrhosis was induced using tetrachlormethane (CCL4) inhalation and bile duct ligation (BDL) models in rats, non-cirrhotic portal hypertension by partial portal vein ligation (PPVL). Intestinal manipulation (IM) as a model of extrahepatic abdominal surgery was performed. 2 and 7 days after IM, portal pressure was measured in-vivo. Hydroxyproline measurements, Sirius Red staining and qPCR measurements of the liver were performed for evaluation of fibrosis development and hepatic inflammation. Laboratory parameters of liver function in serum were analyzed.Results: Portal pressure was significantly elevated 2 and 7 days after IM in both models of cirrhosis. In the non-cirrhotic model the trend was the same, while not statistically significant. In both cirrhotic models, IM shows strong effects of decompensation, with significant weight loss, elevation of liver enzymes and hypoalbuminemia. 7 days after IM in the BDL group, Sirius red staining and hydroxyproline levels showed significant progression of fibrosis and significantly elevated mRNA levels of hepatic inflammation compared to the respective control group. A progression of fibrosis was not observed in the CCL4 model.Conclusion: In animal models of cirrhosis with continuous liver injury (BDL), IM increases portal pressure, and development of fibrosis. Perioperative portal pressure and hence inflammation processes may be therapeutic targets to prevent post-operative decompensation in cirrhosis.

Equine inflammatory response to abdominal surgery in the absence of gastrointestinal disease.

To investigate the, equine inflammatory response to ventral midline celiotomy in the absence of gastrointestinal disease in horses of varying body condition scores primarily using serial measurements of serum amyloid A (SAA). Experimental clinical study. University teaching hospital. Ten adult light breed horses free of any clinical disease, 5 with body condition score (BCS) 3-4/9 and 5 with BCS 7-8/9. Horses had a ventral midline celiotomy performed under general anesthesia, including manual decompression of the small intestine. SAA, semiquantitative fibrinogen, plasma lactate, and WBC count were measured in the blood preoperatively and at 12, 24, 48, 72, 120, and 168hours postoperatively. Complete serum biochemistry was performed preoperatively and 24 and 72hours postoperatively. Serial abdominocentesis was also performed with peritoneal fluid analysis of SAA, total protein, lactate, WBC count, and cytology. Significant (P<0.05) increases in serum SAA were noted at 12, 24, and 48hours postoperatively (124.6 ± 68.6, 390.8 ± 209.0, 568.6 ± 197.7μg/mL), and most horses had values approaching normal at 168hours postoperatively (174.4 ± 307.7μg/mL). Other values such as fibrinogen also increased in response to surgery but did not return to normal within the measured time points. Horses with high BCS did not have significantly different serum SAA compared to horses with low BCS. Peritoneal fluid SAA did not increase significantly at 12hours postoperatively. The information from this study can be used to help determine the effect of anesthesia and surgical intestinal manipulation resulting in increased SAA when a comparison to clinical or experimental cases is needed.

Use of quantitative real-time PCR to determine the local inflammatory response in the intestinal mucosa and muscularis of horses undergoing small intestinal resection.

Studies in rodents and humans have demonstrated that intestinal manipulation or surgical trauma initiates an inflammatory response in the intestine which results in leucocyte recruitment to the muscularis externa causing smooth muscle dysfunction. To examine the intestinal inflammatory response in horses undergoing colic surgery by measuring relative differential gene expression in intestinal tissues harvested from surgical colic cases and control horses. Prospective case-control study. Mucosa and muscularis externa were harvested from healthy margins of resected small intestine from horses undergoing colic surgery (n=12) and from intestine derived from control horses euthanised for reasons unrelated to the gastrointestinal tract (n=6). Tissue was analysed for genes encoding proteins involved in the inflammatory response: interleukin (IL) 6 and IL1β, C-C motif chemokine ligand 2 (CCL2), tumour necrosis factor (TNF), prostaglandin-endoperoxide synthase 2 (PTGS2) and indoleamine 2,3-dioxygenase (IDO1). Relative expression of these genes was compared between the two groups. Further analysis was applied to the colic cases to determine whether the magnitude of relative gene expression was associated with the subsequent development of post-operative reflux (POR). Samples obtained from colic cases had increased relative expression of IL1β, IL6, CCL2 and TNF in the mucosa and muscularis externa when compared with the control group. There was no difference in relative gene expression between proximal and distal resection margins and no association between duration of colic, age, resection length, short-term survival and the presence of pre-operative reflux and the relative expression of the genes of interest. Horses that developed POR had significantly greater relative gene expression of TNF in the mucosa compared with horses that did not develop POR. Small sample size per group and variation within the colic cases. These preliminary data support an upregulation of inflammatory genes in the intestine of horses undergoing colic surgery.

Electroacupuncture accelerates the delayed intestinal transit in POI by suppressing M1 like muscularis macrophages and IL6 secretion.

Electroacupuncture (EA) at ST-36 could accelerate the delayed gastrointestinal (GI) motility in many GI motility dysfunction models, but the definite effect and mechanisms are unclear. In this study, we intended to investigate the effects of EA on intestinal manipulation (IM) mice model and involved mechanisms. Male C57BL/6 mice were randomized into five groups: normal control, intestinal manipulation (IM), IM with sham EA (SEA), IM with high-frequency EA (HEA), and IM with low-frequency EA (LEA). The GI transit was evaluated. The infiltration of muscularis macrophages (MMφ) and its phenotype were analyzed with flow cytometry. Magnetic-activated cell sorting was applied to isolate MMφ, and the relationship between the MMφ and interstitial cells of Cajal (ICCs) was further investigated. (1) Compared with the IM group, HEA and LEA attenuated the delayed intestinal transit. (2) Both the HEA and LEA obviously reduced the MMφ and suppressed the M1 activation of the MMφ in the ileum. (3) EA restored the disrupted ICC networks through inhibiting the release of IL6 by the MMφ. (1) Electroacupuncture at acupoint ST-36 could accelerate the delayed intestinal transit in the IM murine model by restoring the ICC networks. (2) EA protected the ICCs through reducing the MMφ, inhibiting its M1 polarization and its IL6 secretion.