Network analysis and experimental verification of Schisandrin B reduces intestinal ischemia reperfusion injury / 中国临床药理学与治疗学

AIM: To explore schisandrin B (Sch B) pretreatment reduces intestinal ischemia reperfusion injury (IIRI) through inhibiting apoptosis by activation of Nrf2/HO-1 signing pathway in mice by network pharmacology and in vivo experiment. METHODS: (1) The targets of Sch B and IIRI were searched from online databases, Drawing Venn diagram to obtain the common target of them. Cytoscape software was imported to construct the protein-protein interaction (PPI) network to establish the "Drugs-Disease-core target gene" network. The mechanism of Sch B against IIRI was predicted through GO and KEGG enrichment analysis. (2) Thirty-six C57BL/6J mice were randomly divided into six groups (n = 6). The model of IIRI was established in four groups except the sham operation group. Three of the groups were pretreated with Sch B, Nrf2 inhibitor ML385, and Sch B + ML385, respectively. After the experiment, intestinal tissue samples were taken for HE staining, Chiu ' s score, apoptosis staining, immunohistochemistry (IHC), and immunoblotting (Western blot). RESULTS: A total of 412 Sch B related tar- gets, 2 166 IIRI related targets and 153 common targets were screened out through network pharmacology. There were 88 "Sch B-IIRI-core target gene" included NFE2L2 (Nrf2), HMOX1 (HO-1), BCL2, CASP3 (caspase 3), and so on. KEGG enrichment analysis screened 163 related pathways, apoptosis pathway ranked high showing that the pathway may play a key role in the treatment of IIRI by Sch B. The animal experiment had shown that Sch B reduced the Chiu's score and apoptotic while upregulating Nrf2, HO-1, Bcl-2 protein expression levels and Bcl-2/Bax, downregulating Bax, and cleaved caspase-3 expression levels, thereby reducing IIRI in mice, and that Nrf2 inhibitor ML385 reversed this process (P < 0.05). CONCLUSION: This study reveals that Sch B has the characteristics of multi-target and multi-pathway in the reduction of IIRI, and Sch B can reduce IIRI through inhibiting apoptosis by activation of Nrf2/ HO-1 pathway.

Research progress of autophagy in intestinal ischemia-reperfusion injury / 中国临床药理学与治疗学

Intestinal ischemia/reperfusion injury (ll/RI) is a common pathological process in clinical practice. Ischemia/reperfusion causes damage to intestinal mucosa and distant organs, and induces systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). Autophagy is a defense regulation mechanism under stress conditions, which can maintain the homeostasis of cytoplasm, proteins and organelles. The mechanism of autophagy is complex, which is Intestinal ischemia/reperfusion injury (II/RI) is a common pathological process in clinical practice. Ischemia/reperfusion causes damage to intestinal mucosa and distant organs, and induces systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). Autophagy is a defense regulation mechanism under stress conditions, which can maintain the homeostasis of cytoplasm, proteins and organelles. The mechanism of autophagy is complex, which is co-regulated by protein complexes encoded by evolutionarily conserved autophagy-related gene (ATG) and a variety of signaling molecules and pathways. Studies have found that autophagy is involved in the process of intestinal ischemia-reperfusion injury. Therefore, revealing the mechanism of autophagy in II/RI can provide evidence for the prevention and treatment of II/RI.

Protection of intestinal immune barrier against ischemia/reperfusion injury in a swine model using anisodamine hydrobromide

Abstract Intestinal ischemia/reperfusion (I/R) causes barrier impairment and bacterial influx. This study explored the protective effects of anisodamine hydrobromide (AH) on intestinal I/R injury caused by cardiopulmonary resuscitation (CPR) after cardiac arrest (CA). After successful CPR, minipigs were randomly divided into two groups (n = 8): saline and AH (4 mg/kg), and then treated with saline or AH via central venous injection, respectively. The same procedures without ventricular fibrillation initiation were conducted in the Sham group (n = 8). Levels of interferon gamma (IFN-γ) and interleukin 4 (IL-4) were measured at different time points (0, 0.5, 1, 2, 4, and 6 h) in serum and 6 h in gut associated lymphoid tissues (GALTs) after the return of spontaneous circulation (ROSC) to evaluate changes in the proportion of T-helper type 1 (Th1) and T-helper type 2 (Th2). Moreover, the positive culture rates of GALTs were examined to evaluate bacterial translocation. AH treatment markedly alleviated aberrant arterial blood gas and hemodynamics as well as intestinal macroscopic and morphological changes after CPR. Moreover, AH treatment significantly increased IFN-γ and decreased IL-4 in both serum and GALTs. Furthermore, AH treatment dramatically decreased positive bacterial growth in GALTs. AH treatment mitigated immunosuppression caused by intestinal I/R and protected the intestinal immune barrier against bacterial translocation, thereby reducing the risk of secondary intestinal infection

Research progress on the role of pyroptosis in intestinal ischemia-reperfusion injury / 中国临床药理学与治疗学

Pyroptosis is a newly discovered programmed cell death that can lead to inflammatory response, its occurrence depends on the sequential activation of inflammatory bodies and caspase, and then the pore-forming generated by the fragmentation of gasdermin D and its cell membrane polymerization. Pyroptosis is mainly comprised of the pathway that depends on caspase-1 activated by flammasomes and the non-classical pathway that depends on caspase-4/5/11 activated by cytoplasmic lipopolysaccharide. As an important mechanism mediating the inflammatory response of the body, pyroptosis plays an irreplaceable role in the body's response to noxious stimuli, which is closely related to many diseases such as nervous system diseases, cardiovascular system diseases and tumors. Recent studies have found that pyroptosis also plays a key role in the occurrence of intestinal ischemia-reperfusion (II/RI). This paper reviews the molecular characteristics, mechanism of pyroptosis and its relationship with II/RI in recent years, in order to provide theoretical basis for the prevention and treatment of II/RI.

Melatonin can be, more effective than N-acetylcysteine, protecting acute lung injury induced by intestinal ischemia-reperfusion in rat model

OBJECTIVES: The current study compared the impact of pretreatment with melatonin and N-acetylcysteine (NAC) on the prevention of rat lung damage following intestinal ischemia-reperfusion (iIR). METHODS: Twenty-eight Wistar rats were subjected to intestinal ischemia induced by a 60 min occlusion of the superior mesenteric artery, followed by reperfusion for 120 min. Animals were divided into the following groups (n=7 per group): sham, only abdominal incision; SS+iIR, pretreated with saline solution and iIR; NAC+iIR, pretreated with NAC (20 mg/kg) and iIR; MEL+iIR, pretreated with melatonin (20 mg/kg) and iIR. Oxidative stress and inflammatory mediators were measured and histological analyses were performed in the lung tissues. RESULTS: Data showed a reduction in malondialdehyde (MDA), myeloperoxidase (MPO), and TNF-alpha in the animals pretreated with NAC or MEL when compared to those treated with SS+iIR (p<0.05). An increase in superoxide dismutase (SOD) levels in the NAC- and MEL-pretreated animals as compared to the SS+iIR group (34±8 U/g of tissue; p<0.05) was also observed. TNF-α levels were lower in the MEL+iIR group (91±5 pg/mL) than in the NAC+iIR group (101±6 pg/mL). Histological analysis demonstrated a higher lung lesion score in the SS+iIR group than in the pretreated groups. CONCLUSION: Both agents individually provided tissue protective effect against intestinal IR-induced lung injury, but melatonin was more effective in ameliorating the parameters analyzed in this study.

Protective Effect of Salvianolic Acid B on Intestinal Ischemia-reperfusion Injury in Rats / 中国医学科学院学报

To investigate the protective effect of salvianolic acid B(SAB)on the intestinal tract of rats after intestinal ischemia-reperfusion injury(IIRI). Forty-eight healthy male SD rats were equally randomized into IIRI group,SAB+IIRI group,sham control group,and SAB+sham control group. The malonyldialdehyde(MDA)level and superoxide dismutase(SOD)activity in the ileum were measured in each group according to the kit instructions,the transcription levels of inflammatory factors in the ileum of rats were detected by real-time fluorescence quantitative RT-PCR,the secretion level of inflammatory factors was detected by ELISA,and the effects of intestinal ischemia-reperfusion on intestinal permeability and histological lesions were measured by histopathology. The MDA level in IIRI group was significantly higher than those in negative control group(=0.005)and SAB+IIRI group(=0.012). SOD activity of IIRI group was significantly lower than those of negative control group(=0.006)and SAB+IIRI group(=0.017). The optical densities of tumor necrosis factor-α(TNF-α)(=0.003,=0.009),interleukin(IL)-1β(=0.026,=0.005),IL-6(=0.015,=0.003),and nuclear factor kappa-B(NF-κB)(=0.007,=0.015)in IIRI group were significantly higher than those in sham control group and SAB+IIRI group. The TNF-α(=0.002,=0.006),IL-1β(=0.002,=0.006),IL-6(=0.008,=0.002),and NF-κB(=0.026,=0.005)levels in IIRI group were significantly higher than those in sham control group and SAB+IIRI group. The inulin level in IIRI group was significantly lower than that in negative control group(=0.015)and significantly higher than that in SAB+IIRI group(=0.011). The dextran level in IIRI group was significantly lower than those in sham control group(=0.011)and SAB+IIRI group(=0.012). The dextran gel level in IIRI group was significantly higher than those in sham control group(=0.031)and SAB+IIRI group(=0.020). SAB pretreatment remarkably improved the edema,necrosis,and villus stripping of the intestinal mucosa in the ileum of rats. The Chiu score was significantly higher in SAB+sham control group than in sham control group(=0.001)and was significantly lower in SAB+IIRI group than in IIRI group(=0.001). SAB pretreatment can alleviate IIRI in rat models,and this protective effect may be achieved by alleviating oxidative stress and inflammation in the intestinal tract.

Glabridin alleviates ischemia/reperfusion-induced functional failure of smooth muscle of rat ileum by upregulating the cAMP / Glabridin alivia la falla funcional inducida por isquemia/reperfusión del músculo liso de ileum murino regulando el incremento de cAMP

Despite the development of modern medicine, alternative medicine, which has not lost its timeliness, remains attractive for the treatment of various diseases. Glabridin, a major flavonoid of Glycyrrhiza glabra, is known for its antioxidant and anti-inflammatory activity. The aim of this study was: 1) to determine the possible protective role of glabridin against ischemia/reperfusion (I/R) injury of the intestine; 2) to evaluate the in vitrocontractile responses of ileum smooth muscles to acetylcholine after an intestinal I/R; and 3) to explain the underlying molecular mechanism of its effect. Rats were assigned to groups of six rats each; 1) I/R, 2) gla10, 3) gla20, 4) gla40, 5) N5-[imino(nitroamino)methyl]-L-ornithine, methyl ester monohydrochloride (L-NAME)+gla40, and 6) Sham group. The healing effect of glabridin was abolished by L-NAME. Glabridin did not cause contractility of the smooth muscles to acetylcholine-induced contractile responses in intestinal I/R. Yet, it increased to spontaneous basal activity.

A pesar del desarrollo de la medicina moderna, la medicina alternativa, sin perder su vigencia, sigue siendo atractiva para el tratamiento de varias enfermedades. Glabradina, el flavonoide mayoritario de Glycyrrhiza glabra, es conocido por su actividad antioxidante y antiinflamatoria. Los propósitos de este estudio fueron: 1) Determinar el posible rol protector de glabradina ante daños intestinales por isquemia/reperfusion (I/R) 2) Evaluar in vitrolas respuestas de contracción de los músculos lisos del ileum ante acetilcolina después de I/R intestinal; y 3) Explicar el mecanismo molecular subyacente de este efecto. Se asignaron grupos de seis ratas: 1) I/R, 2) gla10, 3) gla20, 4) gla40, 5) N5-[imino(nitroamino)metil]-L-ornithina, metil ester monohidrochloruro (L-NAME)+gla40, y 6) Grupo testigo. El efecto curativo de glabridina fue abolido por L-NAME. Glabridina no causó contracción en el músculo liso como respuesta acetilcolina-inducida I/R. Además, incrementa la actividad basal expontánea.

Baicalein attenuates acute lung injury induced by intestinal ischemia/reperfusion via inhibition of nuclear factor-κ B pathway in mice / 中华危重病急救医学

Objective To investigate the effects of baicalein (Bai) on acute lung injury (ALI) induced by intestinal ischemia/reperfusion (I/R) and its mechanism in mice.Methods Twenty-four male C57BL/6J mice were divided into three groups by random number table:namely sham group,I/R group and Bai+I/R group,with 8 mice in each group.Intestinal I/R induced lung injury model was reproduced by clamping superior mesenteric artery for 90 minutes,followed by reperfusion.Bai (100 mg/kg) was intraperitoneally injected 1 hour before ischemic challenge in the Bai+I/Rgroup.The mice in sham group underwent the similar procedure with I/R group but without vascular occlusion.All mice were sacrificed at 4 hours of reperfusion,and blood was collected from inferior vena cava and lung tissues were harvested.Lung tissues were stained with hematoxylin-eosin (HE),and histological changes were examined under light microscope for pathological score.Lung wet/dry (W/D) ratio was calculated.Lung cell apoptosis was determined by TdT-mediated dUTP nick end labeling (TUNEL) technique.Serum levels of tumor necrosis factor-α (TNF-α) and interleukin-6(IL-6) were determined by enzyme-linked immunosorbent assay (ELISA).The mRNA expressions of TNF-α and IL-6 in lung tissues were determined by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR).The protein expression levels of cytoplasmic inhibitory factor-α of nuclear factor-κB (IκB-α) and nucleus NF-κB were determined by Western Blot.Results Under light microscope,a normal lung tissue structure was shown in the sham group and no evidence of obvious lung injury was found.In the I/R group,the alveolar structure was seriously damaged.The alveolar wall was widened and there was significant interstitial edema and leukocytes infiltration.In the Bai+I/R group,pathological damage was significantly decreased as indicated by reduced lung tissue edema and leukocytes infiltration.Compared with the sham group,the lung pathological scores,W/D ratio and cellular apoptosis in the I/R group were significantly increased.Bothserum TNF-α and IL-6 contents and lung TNF-α and IL-6 mRNA expressions were significantly increased.Furthermore,I/R significantly resulted in a decrease of IκB-α in the cytoplasm and an increase of NF-κB in the nucleus.Notably,Bai treatment significantly attenuated ALI induced by intestinal I/R injury.Compared with the I/R group,the lung pathological scores and W/D ratio in the Bai+I/R group were significantly decreased (lung pathological score:4.59±1.17 vs.6.27±1.34,W/D ratio:3.79±0.28 vs.4.32±0.57),cellular apoptosis was significantly decreased [(4.85 ± 2.47)％ vs.(8.15 ± 2.33)％],both serum TNF-α and IL-6 contents and lung TNF-α and IL-6 mRNA expressions were significantly decreased [serum TNF-α (pg/L):124.18±30.49 vs.167.72 ± 38.65,IL-6 (ng/L):1.65 ± 0.69 vs.2.43 ± 0.57;lung TNF-α mRNA (2-△△Ct:4.75 ± 2.38 vs.7.69 ± 2.32,IL-6 mRNA (2-△△ Ct):16.45 ±4.39 vs.27.69 ± 6.82],additionally,Bai pretreatment significantly increased cytoplasmic IκB-α protein expression (gray value:0.47 ± 0.11 vs.0.27 ± 0.09),while decreased nuclear NF-κB protein expression (gray value:0.57 ± 0.13 vs.1.07 ± 0.14,all P ＜ 0.05).Conclusion Bai could attenuate intestinal I/R injury induced ALI via the inhibition of inflammation and apoptosis.

Tolerance for intestinal ischemia of mouse by astragalus preconditioning / 实用医学杂志

Objective To investigate the protective effects of astragalus preconditioning on the tolerance of ischemia time of mouse small intestine . Methods C57BL/6 mice were randomly divided into 5 groups (n = 7): sham operation group (Sham group),intestinal ischemia reperfusion group (IR group) and astragalus preconditioning group (ASIR group). IR group and ASIR group include 2 sub-groups respectively, specifically, 2 h reperfusion was performed 45 min (ASIR1) and 60 min (ASIR1) after blocking superior mesenteric artery. Intestinal terminal morphology was observed by light microscope after HE coloration . Serum levels of LPS , DAO and intestinal mucosa TNF-α were measured by ELISA. Intestinal Cyto C expression were detected by immunofluorescence. Results Astragalus preconditioning reduces Chiu′s score significantly. Expression of Cyto C was significantly down-regulated in astragalus preconditioning groups, and levels of LPS, DAO and TNF-αsignificantly decreased. The damages in IR2 group is obviously severe than in IR1, but there were no significant differences between this two groups after pretreatment with astragalus. Conclusion Astragalus preconditioning has obvious protective effects to intestinal ischemia reperfusion, and enhances the tolerance to longer time of ischemia.

Effects of glutamine in combination with umbilical cord blood mesenchymal stem cell transplantation on intestinal ischemia reperfusion injury in rats / 中国比较医学杂志

Objective To investigate the effect of glutamine in combination with umbilical cord blood mesenchymal stem cells ( MSCs) transplantation on intestinal ischemia-reperfusion injury in rats.Methods Umbilical cord blood mesenchymal stem cells were isolated, and were labeled with CM-DiI fluorescent dye.Eighty Sprague-Dawley rats were randomly divided into normal control group, ischemia reperfusion injury group, glutamine group, MSCs transplantation group and combined group with 15 rats in each group.The control group received saline enema.The injury group was treated with TNBS ( ethanol dilution) enema.The glutamine group at 1 h after TNBS received intravenous injection of 0.45 g/kg glutamine.The rats of MSCs transplantation group had tail vein injection of 1 ×1010/L umbilical cord blood mesenchymal stem cell suspension, and the combined group received intravenous injection of glutamine 0.45 g/kg and 1 ×1010/L umbilical cord blood mesenchymal stem cell suspension.ELISA was used to detect the midgut fatty acid binding protein (iFABP), interleukin 6 (IL-6), and superoxide dismutase (SOD) content in the rat serum.The water content of intestinal tissue was detected at 1 h and 3 h after reperfusion in each group.The expressions of NF-kB, Bcl-2 and caspase-3 mRNA and proteins in the rat intestinal epithelial cells after treated with glutamine in combination with MSCs were detected by RT-PCR and Western blot assays.Results The fluorescent tracer method revealed that the transplanted MSCs cells were distributed in the intestinal mucosal lymphoid tissues and glandular epithelial cells, indicating that MSCs might be involved in the repair process of intestinal ischemia-reperfusion injury.The content of serum IFABP and IL-6 in the injured group was significantly higher than that in the control group, while significantly reduced in the glutamine group, MSCs transplantation group and combined group, with the most obvious in the combined group.The content of SOD in the injury group was significantly lower than that in the control group, and significantly increased than that in the glutamine group, MSCs transplantation group, with the most striking in the combined group ( P0.05).Compared with the control group, the caspase-3 and NF-kB mRNA and protein expressions in the intestinal mucosal epithelial cells of the injury group were significantly increased, and the expressions of Bcl-2 mRNA and protein were significantly reduced ( P 0.05), but there was a significant difference between these two groups and the combined group (P<0.05).Conclusions After treated with glutamine and MSCs transplantation, the degree of intestinal ischemia reperfusion injury is obviously reduced in rats.It may be mediated through inhibiting the expression of caspase-3 and NF-kB and promoting the expression of Bcl-2.

Expression and significance of inositol requiting enzyme1α and tumor necrosis factor receptor-associated factor 2 in rats' intestinal mucosa with intestinal ischemia-reperfusion injury / 中华实用儿科临床杂志

Objective To investigate the expression of inositol requiting enzyme1 α (IRE1 α) and tumor necrosis factor receptor-associated factor 2 (TRAF2) and its significance through establishing models of intestinal ischemia reperfusion injury (IIRI) in rats.Methods According to the random number table,50 male SD rats were randomly divided into 2 groups:sham operation group (n =10) and ischemia reperfusion (I/R) group (n =40).Sham group animals underwent laparotomy.I/R group rats were subjected to occlusion of the superior mesenteric artery for 30 min;then the blood flow was restored.I/R group animals were divided into 4 subgroups:2 h,6 h,12 h,24 h according to the time of reperfusion.Eight rats were examined based on the number of live rats in each subgroup.The HE staining pathological changes in intestinal samples were observed by the light microscope.The small intestinal epithelial cell apoptosis index (AI) was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL).The expression levels of intestinal tissues tumor necrosis factor α (TNF-α) and plasma intestinal fatty acid-binding protein (Ⅰ-FABP) were detected by ELISA tests.Situ end labeling method was used to detect intestinal cell AI.Western blot was applied to investigate the expression of endoplasmic reticulum stress(ERS) proteins IRE1α,phosphorylation IREIα (p-IRE1 α) and TRAF2 in all group rats intestinal tissues.Results (1)The pathological changes showed that the intestinal injury of I/R groups was more severe than that of sham group,especially at 6 h.(2) Compared with sham group,the expression levels of TNF-α [sham group (16.41 ± 4.44)ng/ L,2 h group:(79.71 ± 8.20) ng/L,6 h group:(131.70 ± 11.59) ng/L,12 h group:(94.23 ±7.66) ng/L,24 h group:(69.78 ± 9.58) ng/L],AI[sham group:(3.93 ±0.77)％,2 h group:(16.24 ± 1.97)％,6 h group:(42.19 ±2.40)％,12 h group:(37.79 ± 2.34)％,24 h goup:(10.38 ±1.46)％] and plasma Ⅰ-FABP [sham group:(0.65 ±0.10) × 103 ng/L,2 h group:(1.47 ±0.10) ×103 ng/L,6 h group:(2.36 ±0.17) ×103 ng/L,12 h group:(37.79 ±2.34) ×103 ng/L,24 group:(l.41 ±0.09) × 103 ng/L] were higher (F =231.462,149.032,162.491,all P ＜ 0.01).(3) The expression of TRAF-2 protein and p-IRE1 α/IRE1 α could be up-regulated after IIRI (F =40.473,59.59,P ＜ 0.01).The expression of these proteins was up-regulated 2 h after reperfusion,peaking at 6-12 h reperfusion,and then decreased at 24 h,and the variation tendencies of all groups were the same.Conclusions IIRI could induce ERS,activate IRE1 α and up-regulate TRAF2.IRE1α/TRAF2 mediating ERS might be involved in regulating the cell inflammation,apoptosis and increasing intestinal permeability after IIRI.

Pretreatment with remifentanil protects against the reduced-intestinal contractility related to the ischemia and reperfusion injury in rat / Pré-tratamento com remifentanil protege contra a redução da contratilidade intestinal relacionada à lesão de isquemia e reperfusão em ratos

BACKGROUND AND OBJECTIVES: Serious functional and structural alterations of gastrointestinal tract are observed in failure of blood supply, leading to gastrointestinal dismotility. Activation of opioid receptors provides cardioprotective effect against ischemia-reperfusion (I/R) injury. The aim of the present study was to determine whether or not remifentanil could reduce I/R injury of small intestine. METHODS: Male Wistar Albino rats were subjected to mesenteric ischemia (30 min) followed by reperfusion (3 h). Four groups were designed: sham control; remifentanil alone; I/R control; and remifentanil + I/R. Animals in remifentanil + I/R group were subjected to infusion of remifentanil (2 ug kg-1 min-1) for 60 min, half of which started before inducing ischemia. Collecting the ileum tissues, evaluation of damage was based on contractile responses to carbachol, levels of lipid peroxidation and neutrophil infiltration, and observation of histopathological features in intestinal tissue. RESULTS: Following reperfusion, a significant decrease in carbachol-induced contractile response, a remarkable increase in both lipid peroxidation and neutrophil infiltration, and a significant injury in mucosa were observed. An average contractile response of remifentanil + I/R group was significantly different from that of the I/R group. Lipid peroxidation and neutrophil infiltration were also significantly suppressed by the treatment. The tissue samples of the I/R group were grade 4 in histopathological evaluation. In remifentanil + I/R group, on the other hand, the mucosal damage was moderate, staging as grade 1. CONCLUSIONS: The pretreatment with remifentanil can attenuate the intestinal I/R injury at a remarkable degree possibly by lowering lipid peroxidation and leukocyte infiltration.

JUSTIFICATIVA E OBJETIVOS: Alterações funcionais e estruturais sérias do trato gastrointestinal são observadas na insuficiência de irrigação sanguínea, levando a alterações da motilidade gastrointestinal. A ativação dos receptores opioides proporciona um efeito cardioprotetor contra a lesão de isquemia/reperfusão (I/R). O objetivo do presente estudo foi determinar se remifentanil pode ou não reduzir a lesão de I/R do intestino delgado. MÉTODOS: Ratos machos albinos, da linhagem Wistar, foram submetidos à isquemia mesentérica (30 minutos) seguida de reperfusão (3 horas). Quatro grupos foram designados: sham controle; remifentanil isolado; controle I/R; remifentanil + I/R. Os animais do grupo remifentanil + I/R foram submetidos à infusão de remifentanil (2 µg kg-1 min-1) por 60 min, metade dos quais iniciou antes da indução da isquemia. Coletando os tecidos do íleo, a avaliação dos danos foi baseada nas respostas contráteis ao carbacol, nos níveis de peroxidação lipídica e infiltração de neutrófilos e na observação das características histopatológicas no tecido intestinal. RESULTADOS: Após a reperfusão, uma diminuição significativa da resposta contrátil induzida por carbacol, um notável aumento tanto da peroxidação lipídica quanto da infiltração de neutrófilos e uma lesão significativa da mucosa foram observados. A média da resposta contrátil no grupo remifentanil + I/R foi significativamente diferente daquela do grupo I/R. A peroxidação lipídica e a infiltração de neutrófilos também foram significativamente suprimidas pelo tratamento. As amostras de tecido do grupo I/R apresentaram grau 4 na avaliação histopatológica. No grupo remifentanil + I/R, por outro lado, a lesão da mucosa foi moderada, apresentando estadiamento de grau 1. CONCLUSÕES: O pré-tratamento com remifentanil pode atenuar a lesão intestinal de I/R em um grau notável, possivelmente pela redução da peroxidação lipídica e da infiltração leucocitária.

The effects of lymph after intestinal ischemia/reperfusion on the inflammatory factors and Toll-like receptor 4 ligand high mobility group box-1 in Toll-like receptor 4 deficient mice / 中华临床营养杂志

Objective To investigate the effects of lymph from ischemic/reperfused intestine on the inflammatory factors and Toll-like receptor 4 (TLR4) ligand high mobility group box-1 (HMGB1) in TLR4 deficient (TLR4-/-) mice.Methods A total of 20 SD rats weighing (300 ±20) g were randomly assigned into two groups:lymph drainage group (group N,lymph drainage for 180 minutes without other treatment) and intestinal ischemia/reperfusion group (group I/R,draining the lymph for 180 minutes while clipping the superiormesenteric artery for 60 minutes followed by 120-minute reperfusion).Thirty-two TLR4-/-mice and thirty-two C57BL/6 wild type (WT) mice were each divided into 4 sub-groups (n =8),injected with different fluids through the caudal vein:group N with normal lymph;group I/R with I/R lymph;group Edt with endotoxin;group HMGB1 with HMGB1 protein.The mice were sacrificed 180 minutes after the injection for sample collection.Results The levels of endotoxin and HMGB1 in the lymph drainage of the group I/R rats were significantly higher than that of the group N rats [(0.034 ± 0.050) Eu/ml vs.(0.017 ± 0.023) Eu/ml,P =0.033;(4.293 ± 0.883) ng/ml vs.(0.509 ± 0.128) ng/ml,P =0.006].In the mice injected with HMGB1,the mucosa thickness and villus height in the ileum of the WT mice were significantly lower than that of the TLR4-/-mice [(335.8±43.2) μmvs.(602.1±37.5) μm,P=0.000;(273.0±31.7) μm vs.(404.5 ± 18.6) μm,P =0.000];in both WT and TLR4-/-mice injected with the I/R lymph drainage,the mucosa thickness and virus height were decreased,but the decrements were significantly lower in TLR4-/-mice;there were no statistically significant differences in the levels of interleukin-6 (IL-6),tumor necrosis factor-α (TNF-α),endotoxin,and HMGB1 between the TLR4-/-and the WT mice injected with normal lymph or endotoxin.In the mice injected with I/R lymph drainage,the levels of inflammatory factors in the TLR4-/-mice were significantly lower than those in the WT mice [TNF-α:(28.637 ±5.166) pg/ml vs.(41.917 ±8.175) pg/ml,P=0.000;IL-6:(60.900 ±24.729) pg/ml vs.(110.265 ±28.545) pg/ml,P =0.000].In the mice injected with HMGB1,the levels of inflammatory factors in the TLR4-/-mice were significantly decreased compared with those in the WT mice [TNF-α:(20.865 ± 6.464) pg/ml vs.(31.059 ± 6.204) pg/ml,P=0.004;IL-6:(36.268 ±8.977) pg/ml vs.(76.677 ± 14.099) pg/ml,P=0.000].Conclusions The concentrations of endotoxin and HMGB1 are significantly increased during intestinal I/R in rats.After injection of I/R lymph drainage,endotoxin,and HMGB1,the levels of inflammatory factors and HMGB1 in the mice injected with I/R lymph drainage are significantly higher than those in the mice injected with normal lymph;the levels of inflammatory factors and local damage of intestinal mucosa are significantly reduced in the TLR4-/-mice than in the WT mice.The gut-lymph pathway may play a key role in the intestinal I/R injury.

Protective effects of glutamine pretreatment on occludin protein in rats with intestinal ischemia-reperfusion injury / 中国病理生理杂志

AIM:To determine the effects of glutamine ( Gln) pretreatment on occludin protein in the rats with intestinal ischemia-reperfusion ( I/R ) injury.METHODS: Male Wistar rats ( n =30 ) were randomly divided into 3 groups (n=10):sham group, I/R group and Gln pretreatment group.The rats in Gln pretreatment group were pretreated with Gln at dose of 1 g? kg-1? d-1 by orogastric route for 7 d, and those in the other 2 groups were pretreated with the same volume of normal saline .Intestinal I/R was induced by 30-min occlusion of the superior mesenteric artery followed by 24 h of reperfusion.After the operation, the levels of IL-10, IL-2, TNF-α, SOD and MDA were measured.The occludin protein was determined by the methods of immunohistochemistry and Western blotting .RESULTS: The occludin protein level in I/R group was significantly lower than that in sham group and Gln group (P<0.05).The levels of MDA and TNF-αin I/R group were significantly higher than those in sham group and Gln group ( P<0.05 ) .The levels of SOD , IL-10 and IL-2 in I/R group were significantly lower than those in sham group and Gln group ( P<0.05 ) .CONCLUSION:Glutamine has a protective effect on occludin protein in intestinal ischemia-reperfusion injury .The mechanism may be rela-ted to oxidative stress response and inflammatory inhibition .

The effect of S-Nitrosoglutathione on the intestinal epithelial barrier after acute ischemia reperfusion injury / 重庆医学

Objective To investigate the effect of S-Nitrosoglutathione (GSNO)on acute ischemia reperfusion (I/R)induced in-testinal barrier function lesion in a mouse model.Methods Twenty-four 6-8-year-old C57BL/6 mice were divided into 3 groups,8 for each:(1)the sham group;(2)the I/R group;(3)the I/R+GSNO group.The mouse intestine I/R model was established by the occlusion of the superior mesenteric artery temporarily followed by reperfusion for 6 h.Histological changes in the small intestine were observed after HE staining;the expression of claudin-1 protein in the intestine epithelium was assessed by immunohistochem-istry staining as well as western blot analysis.Results Both HE staining and immunohistochemistry results showed the integrate intestinal villi with the continuous Claudin-1 expression alone the villi in the sham group;the intestinal villi of the I/R group partial-ly detached,thickened,crooked and fractured,with the obvious disconnection of Claudin-1 staining alone the top of the villi;while the intestinal villi of the I/R+GSNO group were neatly arranged and damage to intestinal mucosa was much alleviated,accompanied with the marked restoration of the continuity of claudin-1 staining.Compared to the sham group,claudin-1 protein level of for the I/R group and the I/R+GSNO group decreased by 32.5% and 13.8% respectively (P <0.05);and compared to the I/R group,clau-din-1 protein level of the I/R+GSNO group increased by 27.8% (P <0.05).Conclusion Protein level of claudin-1 would decrea-ses after I/R,and pretreatment with GSNO can effectively relieve the damage of intestinal mucosal structure as well as intestinal tight junction barrier through upregulating the expression of claudin-1 protein.

The protective effect of glutamine pretreatment on intestinal ischemia-reperfusion injury and eNOS/NO levels in rats / 天津医药

Objective To investigate the protective effect of glutamine(Gln) pretreatment on intestinal ischemia-reperfusion (I/R) injury and endothelial nitric oxide synthase (eNOS)/nitric oxide (NO) signaling pathway in rat model. Methods Thirty male Wistar rats were randomly divided into three groups(n=10 for each group):sham group, I/R group and Gln group. Animals were pretreated with 1 g/(kg·d)Gln by orogastric route for 7 days in Gln group, and normal saline was given to the other two groups in the same dose. Intestinal I/R was induced by 30 min occlusion of the superior mesenteric artery followed by 24 h of reperfusion. After the operation, the intestinal histopathological changes, the plasma endotoxin level, serum D-lactic acid, eNOS, inducible NOS(iNOS)activity and NO levels were detected by ultraviolet spectrophotometer. The mRNA expressions of myocardial eNOS and iNOS were detected by real-time fluorescence quantitative PCR (RT-PCR). Results After reperfusion, in IR group, extensive epithelial sloughing and mucosal ulceration of villous tips were observed, whereas these findings did not occur in Gln group and sham group. Compared with IR group, the serum NO, eNOS levels and eNOS mRNA expression of intestinal tissue were elevated in Gln group (P<0.01), but the plasma endotoxin level, serum D-lactic acid, serum iNOS and intestinal iNOS mRNA expression decreased in IR group(P<0.05). Conclusion Glutamine pretreatment has protective effects on intestinal ischemia-reperfusion injury in vivo. The mechanism may be related to the inhibition of iNOS expression and the increased expression of eNOS, thereby increasing NO activity.

Effects of glutamine pretreatment on intestinal ischemia-reperfusion inju-ry in rats / 中国病理生理杂志

AIM:To determine the effects of glutamine ( Gln) pretreatment on intestinal ischemia-reperfusion (I/R) injury in the rats.METHODS: Thirty male Wistar rats were randomly divided into 3 groups (n=10): sham group, I/R group and Gln pretreatment group .The rats in Gln pretreatment group were pretreated with 1 g· kg -1 · d-1 Gln by orogastric route for 7 d, the rats in the other 2 groups were pretreated with normal saline .Intestinal I/R was induced by 30-min occlusion of the superior mesenteric artery followed by 24 h of reperfusion .After the operation , the plasma endo-toxin, serum D-lactic acid, superoxide dismutase ( SOD) and malondialdehyde ( MDA) levels were measured .The intesti-nal mucosal injury was observed with HE staining and evaluated using Chiu 's scoring.RESULTS: Serum D-lactic acid, endotoxin level , MDA level and Chiu's score in I/R group were significantly higher than those in sham group and Gln group (all P<0.05).Serum SOD activity was significantly lower than that in sham group and Gln group (P<0.05).CON-CLUSION:Glutamine has a protective effect on the intestines during ischemia-reperfusion injury .The mechanism may be related to oxidative stress response .

Heart injury following intestinal ischemia reperfusion in rats is attenuated by association of ischemic preconditioning and adenosine

PURPOSE: To investigate the effect of ischemic preconditioning (IPC) and adenosine as strategies to protect cardiac injury caused by intestinal IR in rats, based on increasing in adenosine bioavailability and improvement of cell energy state by IPC. METHODS: Male Wistar rats were submitted to 60 minutes of intestinal ischemia and 120 minutes of reperfusion. Intravenous injections of saline or Adenosine (AD) was administered five minutes before ischemia, five minutes before reperfusion and after 55 minutes reperfusion. Cardiac samples were obtained, fixed in formalin solution, embedded in paraffin, and sections of 5 μm were stained by hematoxylin-eosin. Histological analysis of myocardium was performed according occurrence of necrosis signs: piknosis, band contraction, eosinophilic cytoplasm, karyorrhexis and vacuolization (score - zero to 5). RESULTS: The groups submitted to ischemia alone (I=4.0), and reperfusion (IR=4.5) showed highest level of lesion compared to the others (I+IPC=3.3, IR+IPC=3.6, I+AD=3.0, IR+AD=3.8). The most interesting result was association of IPC and AD in IR model (IR+IPC+AD=1.2, p=0.002), showing preservation of the heart tissue, with fibers showing typical cross-striations and nuclei characteristics. Rare and small areas of tissue necrosis was observed and suggestion of capillaries congestion. CONCLUSION: Intestinal ischemia reperfusion promotes cardiac tissue injury. Ischemic preconditioning in association with adenosine is an efficient strategy to protect the heart against ischemia and reperfusion injury. .

Effects of ω-3 polyunsaturated fatty acids intervention on Toll-like receptor 4 and high mobility group box 1 with intestinal ischemia/reperfusion injury / 中华临床营养杂志

Objective To investigate the expressions of Toll-like receptor 4 (TLR4) and high mobility group box 1 (HMGB1) expression on distant tissue during the intestinal ischemia/reperfusion and the effects of ω-3 polyunsaturated fatty acids (ω-3 PUFAs) intervention in rats.Methods Forty-eight Sprague-Dawley male rats,weighing (281.50 ± 22.68) g,were randomly divided into three groups (n =16) after gastrostomy:normal diet (N) group,enteral nutrition (EN) group and EN plus ω-3 PUFAs (PUFA) group.Each group was further divided into lymph drainage (I/R + D) and non-drainage (I/R) sub-groups (n =8 each) according to whether treated with intestinal lymph drainage.All the rats were subjected to 60 min ischemia by clamping the superior mesenteric artery,followed by 120 min reperfusion,while the rats in the I/R + D subgroups were treated with intestinal lymph drainage for 180 min at the same time.Results The interleukin-6 level in lymph in N (I/R + D) group was significantly higher than in the EN (I/R + D) and PUFA (I/R + D) groups (PUFA vs EN vs N:(154.57 ±69.30) ng/L vs (97.58 ±40.34) ng/L vs (85.35 ±23.93) ng/L,P =0.021).Besides,the serum level of HMGB1 in PUFA (I/R + D) group was significantly lower compared to the other 5 groups [PUFA (I/R) vs EN (I/R) vs N (I/R) vs PUFA (I/R + D) vs EN (I/R + D) vs N (I/R + D):(2.95 ± 1.17) μg/L vs (3.86 ±0.99) μg/L vs (4.45 ± 1.73) μg/L vs (1.71 ±1.41) μg/Lvs (2.11±0.56) μg/Lvs (3.13 ±0.79) μg/L,P=0.000],and it also decreased in the PUFA (I/R) and EN (I/R) groups than the N (I/R) group (respectively,P ＜ 0.05).Furthermore,the serum endotoxin level in PUFA (I/R) group was significantly lower compared to the N (I/R) and EN (I/ R) groups[PUFA(I/R) vsPUFA (I/R+D) vsEN (I/R) vs N (I/R):(0.020±0.004) EU/mlvs (0.028 ±0.006) EU/ml vs (0.028 ±0.005) EU/ml vs (0.018 ±0.006) EU/ml,P=0.014].Together the serum tumor necrosis factor-α level in both PUFA (I/R) and PUFA (I/R + D) groups were significantly lower than theEN (I/R),N (I/R) and N (I/R+D) groups [PUFA (I/R+D) vs PUFA (I/R) vs EN (I/R) vsN (I/R) vs N (I/R+D):(12.03 ±6.57) ng/L vs (14.32 ±6.11) ng/Lvs (23.27 ±15.60)ng/L vs (27.42 ± 10.37) ng/L vs (26.87 ± 5.30) ng/L,P =0.013].The jejunum and ileum mucosa in all the I/R groups showed swelling and atrophy and appeared fragile,while the PUFA groups showed less yellow staining and injury than the other two groups (P ＜ 0.05,respectively).In addition,the expressions of TLR4 mRNA in jejunum,ileum,and liver in all the drainage groups were respectively lower than the corresponding non-drainage groups [jejunum:PUFA (I/R) vs EN (I/R) vs N (I/R) vs PUFA (I/R+D) vs EN (I/R+D) vsN (I/R+D):2.32±0.62vs3.08±1.29vs3.50±2.44vs 1.62±0.79vs 1.67±1.11 vs 1.94±0.81,P=0.025; ileum:PUFA (1/R) vsEN (1/R) vsN (1/R) vs PUFA (1/R+D) vsEN (1/R+D) vs N (1/R+D):2.67±1.08 vs 5.22 ± 3.96 vs 6.95 ±4.92 vs 1.70±0.68 vs 1.80±0.29 vs3.68±1.47,P=0.012; liver:PUFA (1/R)vsEN (1/R)vsN (1/R)vs PUFA (1/R+D)vsEN (1/R+D)vsN (1/R+D):5.67 ±1.94 vs 7.50 ±3.89 vs 7.18 ±4.55 vs 1.70 ±0.86 vs 3.90 ± 1.95 vs 4.12 ±2.11,P =0.001],which was consistent with the reduction of HMGB1 and the decrease of nuclear factor-κB activity in intestine,liver,and lung (P =0.000).Conclusions Lymph drainage and ω-3 PUFAs intervention can reduce the production of HMGB1 and inflammation factors,inhibit the expression of HMGB1 and TLR4 mRNA,and thus alleviate distant tissue injury caused by intestinal L/R.

Impact of intestinal ischemia/reperfusion on free amino acid levels in plasma / 中华临床营养杂志

Objective To investigate intestinal mucosal injury and the change of free amino acid levels in plasma with intestinal ischemia/reperfusion.Methods Twenty-four Sprague-Dawley (SD) male rats (SPF grade) were randomly divided into 3 groups with 8 rats in each group:Blank group,Sham group and ischemia/reperfusion (I/R) group.The rats in I/R group were subjected to 60 min ischemia by clamping the superior mesenteric artery (SMA),followed by 120 min repeffusion.All rats were sacrificed with blood withdraw through inferior vena cava.The plasma was precipitated with Sulfosalicylic acid and the supernatant free amino acid levels were measured and the intestinal mucosal thickness and villus length were also assayed.Results In the I/R group the total free amino acids,essential amino acids (EAA),glutamine and branched-chain amino acids (BCCA) were remarkably lower [the total free amino acids:I/R vs Blank vs Sham:(4585.1 326.1) vs (5661.5 ±581.9) vs (5337.9±998.7) μmol/L (F=5.075,P=0.016); EAA:I/Rvs Blank vs Sham:(1401.3 ±183.4) vs (2147.6 ± 265.1) vs (1796.2 ± 440.8) μmol/L (F =1 1.216,P =0.000) ; glutamine:I/R vs Blank vs Sham:(646.1 ± 34.7) vs (895.7 ± 258.8) vs (839.1 ± 163.7) μmol/L (F =4.326,P =0.027) ; BCCA:I/R vs Blank vs Sham:(507.8 ± 119.0) vs (912.2 ± 165.8) vs (671.9 ± 79.8) μmol/L (F =10.662,P =0.001)]and the jejunum and ileum mucosal thickness and villus height were decreased compared to Blank and Sham groups [jejunum mucosal thickness:I/R vs Blank vs Sham:(401.50 ± 117.79) vs (529.22 ±54.73) vs (499.54 ±64.48) μm (F=31.869,P =0.000) ; jejunum villus height:I/R vs Blank vs Sham:(271.37 ± 84.29) vs (365.26 ± 46.98) vs (349.67 ± 56.11) μm (F =30.472,P =0.000) ; ileum mucosal thickness:I/R vs Blank vs Sham:(254.20 ± 43.56) vs (324.70 ± 30.56) vs (298.26 ± 58.46) μm (F =30.442,P =0.000) ; ileum villus height:I/R vs Blank vs Sham:(169.37 ± 37.25) vs (221.62 ± 37.26) vs (193.25 ± 38.39) μm (F =24.145,P =0.000)],and The EAA and BCAA in the I/R group were lower than the Sham group (respectively,P ＜0.05).There was no significant difference in aromatic amino acids (AAA) among the three groups [I/R vs Blank vs Sham:(273.2 ± 37.4) vs (296.8 ± 55.6) vs (281.9 ± 7.3) μmol/L (F =0.578,P =0.570)].The ratio BCAA/AAA in the Sham and I/R groups were significantly lower than the Blank group [(I/R vs Blank vs Sham:(2.4 ±0.6) vs.(1.9 ±0.4) vs (3.1 ±0.7) (F =5.215,P =0.014)],while the I/R group was decreased slightly compared to the Sham group,but the difference was not significant (P ＞ 0.05).The ethanolamine phosphate,taurine,citrulline,cystine,phosphoserine levels were reduced in the Sham and I/R groups compared to the Blank group [ethanolamine phosphate:I/R vs Blank vs Sham:(11.4 ± 1.9) vs (14.3 ± 3.4) vs (10.1±1.7) μmol/L(F=5.897,P=0.009);taurine:I/R vs BlankvsSham:(341.1±36.3) vs(533.2±90.8) vs (439.2±105.4) μmol/L (F=10.702,P=0.001); citrulline:I/R vs Blank vs Sham:(57.7±3.2) vs (73.1 ±16.2) vs (58.1 ±3.8) μmol/L (F=6.360,P =0.007); cystine:I/R vs Blank vs Sham:(20.0 ± 3.6) vs (60.6 ± 24.6) vs (36.3 ± 5.8) μmol/L (F =15.344,P =0.000) ; phosphoserine:I/R vs BlankvsSham:(10.2±1.1) vs (15.8±5.4) vs (11.7 ±3.4) μmol/L (F=4.878,P=0.018)],and the taurine and cystine in I/R groups were significantly decreased than the Sham group (respectively,P ＜ 0.05).The ornithine and arginine were comparatively reduced in I/R in contrast to the Blank and Sham groups [ornithine:I/R vs Blank vs Sham:(81.5 ± 19.0) vs (125.5 ±42.3) vs (114.9 ± 19.5) μmol/L (F =4.961,P =0.017) ;arginine:I/R vs Blank vs Sham:(199.2 ± 8.0) vs (258.9 ± 14.6) vs (248.7 ± 38.4) μmol/L (F =13.940,P =0.000)].The tryptophan and glutamic acid concentrations were increased in the Sham and I/R groups [tryptophan:L/R vs Blank vs Sham:(125.9 ± 12.1) vs (103.1 ± 29.9) vs (128.9 ± 18.5) μmol/L (F =5.429,P =0.031) ; glutamic acid:I/R vs Blank vs Sham:(188.6 ± 29.8) vs (93.6 ± 29.4) vs (125.4 ± 43.8) μmol/L (F =15.241,P =0.000)] and it was lower in the Sham group than the I/R group (P ＜ 0.05).Conclusion Intestinal ischemia-reperfusion can cause intestinal mucosal injury and the change of free amino acid levels in plasma and intestinal barrier damage may be related to the decline glutamine concentration and the increase of protein catabolism.