Rat Small Bowel Research Articles

Possibilities of local effect the healing of small bowel sutures in a rat model of acute intra-abdominal infection

Aims: Investigate the regeneration of the small bowel suture line regeneration after suturing with a material with antioxidant properties. Methodology: 7 intact rats, 63 with simulated intra-abdominal infection (IAI). A laparotomy was performed in 12 h after simulating. The small bowel was cut and sutured in 56 rats (2 groups of 28) after an abdominal lavage. Standard Kapron was used in the control group (CG). Kapron impregnated with a 5% solution of ethylmethylhydroxypyridine succinate was used in the research group (RG). Sections of the small bowel were collected from a total of 21 rats (7 intact rats, 7 rats with intra-abdominal infection (IAI) models, and 7 rats at different time points (1, 3, 5, and 7 days) post suturing) for subsequent histological examination. The preparations were stained with hematoxylin-eosin and by Mikel Calvo. The R/B coefficient (R/BC) was determined. The experiment's time duration was 7.5 days in December 2022. Results: R/BC increased (p<0.05) in the connective tissue fibers of the small bowel submucosal base in 12 h after the simulating of IAI. R/BC increased (p<0.05) in both groups in 1 day after suturing. R/BC increased in CG, decreased (p<0.05) in RG in 3 days. Fibrin was found between the ligature’s fibers in RG. R/BC decreased (p<0.05) in both groups in 5 days, indicators were smaller (p<0.01) in RG. Fibrin was found between the ligature’s fibers in CG, granulation tissue was in RG. R/BC decreased in both groups in 7 days, but indicators were smaller in RG (p<0.01). Unfilled areas in the granulation tissue between the ligature fibers were in CG. Conclusion: 1. The use of ligatures impregnated with the 5% ethylmethylhydroxypyridine succinate solution for suturing the small bowel in rats with intra-abdominal infection models is associated with the significant decrease in the activity of local proteins oxidation and the significant acceleration of local regeneration processes. 2. The creation of a suture material with antioxidant properties may be a promising direction for the prevention of suture leakage

Hymenolepis diminuta

Described first as a taeniid in 1819, the tapeworm Hymenolepis diminuta is at home in the small bowel of rats and expelled from mice by 10–12 days of infection. Distinct among hymenolepids via its unarmed scolex, H. diminuta has served as a model to define tapeworm biochemistry, physiology, and nutrient absorption. H. diminuta infection has been used to dissect host immunological responses to a largely innocuous helminth that does not migrate through the host or invade tissue. With the exception of competing for host nutrients, the lifestyle of H.

A Model of Short Bowel Syndrome in Rodents in a Long-Term Experiment.

Simulation of short bowel syndrome (SBS) in experimental animals is of great interest for studies in translational medicine. The processes of intestinal adaptation are most often studied in rats aged 8-10 weeks with up to 70% resection the small bowel. In this case, the animals are euthanized in 2 weeks after the surgery; further development of the pathological process remains practically unexplored. In our experiment, a number of blood biochemical parameters and morphological signs of intestinal adaptation were assessed within 34 weeks after surgery. It was shown that after resection of 70% of the small bowel in rats (180±15 g), clinical symptoms are observed only during the first 2 weeks, however, the mortality in the group was observed throughout the entire period of the study in the absence of clear clinical signs. Morphological compensatory changes in the walls of the small intestine continued up to 34 weeks after resection, and their morphometry can be used to describe adaptation in the dynamics of the study.

Targeting the Rat's Small Bowel: Long-Term Infusion into the Superior Mesenteric Artery

Targeting the Rat's Small Bowel: Long-Term Infusion into the Superior Mesenteric Artery

Targeting the Rat's Small Bowel: Long-Term Infusion into the Superior Mesenteric Artery.

The superior mesenteric artery can be cannulated in humans through minimally invasive radiological catheterization of the femoral or axillary artery. SMA cannulation is more difficult in rats due to small anatomical dimensions. The aim of the study is to describe a surgical technique for cannulation of the SMA in rats to perform long-term infusion of drugs into the SMA vascular bed in unrestricted animals, which will result in a high rate of catheter patency after the post surgical recovery for 24 hours. To avoid the risk of SMA thrombosis or bleeding from direct access, a proximal branch of the SMA is isolated, ligated distally and cannulated with a 0.25 mm polyurethane capillary tube whose tip is advanced close to the origin of the SMA from the aorta. The cannula is then tunnelled subcutaneously to the back of the animal's neck and through the skin via an artificial valve. The external portion of the cannula is inserted in a semi-rigid support system and connected to the continuous infusion pump outside the cage where the rat is free to move. Correct positioning of the cannula was demonstrated by post-surgical angiography and autopsy findings. Catheter patency after 24 hours of saline infusion into the SMA region was assured in most rats by the total discharge of the pump and recognition of a functional cannula for blood sampling or saline infusion.

Kampo medicines Rikkunshito and Hangeshashinto prevent cisplatin-induced intestinal mucosal injury in rats

Background/PurposeWe examined the effects and mechanisms of rikkunshito (RKT) and hangeshashinto (HST) on cisplatin-induced mucosal injuries in the rat small bowel. MethodsJuvenile rats were divided into 6 groups: sham control, cisplatin injection without kampo medicines, and cisplatin injection with oral administration of low and high doses of RKT (1000 mg/kg and 2000 mg/kg) and HST (500 mg/kg and 1000 mg/kg). Fecal condition, intestinal morphological changes, enterocyte proliferation, and enterocyte apoptosis were assessed. ResultsDiarrhea and atrophy of ileal villi observed in the cisplatin group were significantly improved in all kampo groups. Injury scores of the jejunum were significantly lower with RKT (2000 mg/kg) and HST (500 and 1000 mg/kg) than with cisplatin, and those of the ileum were significantly lower with HST (500 and 1000 mg/kg) than with cisplatin. Enterocyte proliferation of the jejunum was significantly increased with RKT (2000 mg/kg) and HST (500 mg/kg) compared with cisplatin, and those of the ileum were significantly increased in all kampo groups compared with the cisplatin group. Jejunal and ileal apoptosis following cisplatin administration was significantly inhibited by HST. ConclusionsRKT and HST prevented cisplatin-induced intestinal mucosal injury with increasing proliferation of intestinal epithelial cells. HST also attenuated cisplatin-induced crypt cell apoptosis.

MiR-200b in heme oxygenase-1-modified bone marrow mesenchymal stem cell-derived exosomes alleviates inflammatory injury of intestinal epithelial cells by targeting high mobility group box 3

Heme Oxygen-1 (HO-1)-modified bone marrow mesenchymal stem cells (BMMSCs) are effective to protect and repair transplanted small bowel and intestinal epithelial cells (IECs); however, the mechanism and the role of HO-1/BMMSCs-derived exosomes is unclear. In the present study, we aimed to verify that exosomes from a HO-1/BMMSCs and IEC-6 cells (IEC-6s) co-culture system could reduce the apoptosis of IEC-6s and decrease the expression of the tight junction protein, zona occludens 1, in the inflammatory environment. Using mass spectrometry, we revealed that high mobility group box 3 (HMGB3) and phosphorylated c-Jun NH2-terminal kinase (JNK), under the influence of differentially abundant proteins identified through proteomic analysis, play critical roles in the mechanism. Further studies indicated that microRNA miR-200b, which was upregulated in exosomes derived from the co-culture of HO-1/BMMSCs and IEC-6s, exerted its role by targeting the 3′ untranslated region of Hmgb3 in this biological process. Functional experiments confirmed that miR-200b overexpression could reduce the inflammatory injury of IEC-6s, while intracellular miR-200b knockdown could significantly block the protective effect of HO-1/BMMSCs exosomes on the inflammatory injury of IEC-6s. In addition, the level of miR-200b in cells and exosomes derived from HO-1/BMMSCs stimulated by tumor necrosis factor alpha was significantly upregulated. In a rat small bowel transplantation model of allograft rejection treated with HO-1/BMMSCs, we confirmed that the level of miR-200b in the transplanted small bowel tissue was increased significantly, while the level of HMGB3/JNK was downregulated significantly. In conclusion, we identified that exosomes derived from HO-1/BMMSCs play an important role in alleviating the inflammatory injury of IECs. The mechanism is related to miR-200b targeting the abnormally increased expression of the Hmgb3 gene in IECs induced by inflammatory injury. The reduced level of HMGB3 then decreases the inflammatory injury.

Protective effect of genes modified stem cells on the tight junction of damaged small intestinal epithelium

Objective To investigate the role of CXC subfamily chemokine receptor 3 (CXCR3) and heme oxygenase-1 (HO-1) gene-modified bone marrow mesenchymal stem cells (BMMSCs) in protecting tight junctions of transplanted small intestine epithelium. Methods BMMSCs were isolated by whole bone marrow adherence and identified by detecting Cluster of Differentiation 29 (CD29), Cluster of Differentiation 90 (CD90), Classical class Ⅰ major histocompatibility complex (RT1-A), Cluster of Differentiation 34 (CD34), Cluster of Differentiation 45 (CD45) and Classical class Ⅱ major histocompatibility complex (RT1-B) by Flow cytometry. BMMSCs modified by HO-1 gene, CXCR3 gene and CXCR3 adding HO-1 genes were obtained by adenovirus transfection. Experimental models of rat small bowel transplantation rejection were established by using Brown Norway rats as donors and Lewis rats as receptors. The pathology of intestine was analyzed by Hematoxylin-eosin staining and transmission electron microscopy. The expression of zona occludens-1 (ZO-1) in small intestine was detected by Western blotting. Results BMMSCs were long-shuttle type as well as positive for CD29 (99.6%), CD90 (99.8%) and RT1-A (99.8%) but negative for CD34, CD45 and RT1-B. Experimental models of acute rejection of small bowel transplantation were obtained successfully. Compared with the NS group (3.66±0.20), BMMSCs group (3.05±0.59), CXCR3/BMMSCs group (2.76±0.49) and HO-1/BMMSCs group (2.86±0.80), (CXCR3+ HO-1)/BMMSCs significantly alleviated intestinal damage (2.43±0.85, t=-5.996, P<0.05, 7 d). Meanwhile, (CXCR3+ HO-1)/BMMSCs could more significantly protected the tight junction structure and the level of ZO-1 protein in transplanted small intestine than other groups (t=-9.436, P<0.05). Conclusion Compared with single-gene-modified, BMMSCs modified by CXCR3 adding HO-1 could protect the structure and function of tight junctions of transplanted small intestine with better effects. Key words: Bone marrow mesenchymal; CXC subfamily chemokine receptor 3; Heme oxygenase-1; Small intestine transplantation; Zona occludens-1

Transdermal fluorescence detection of a dual fluorophore system for noninvasive point-of-care gastrointestinal permeability measurement.

The intestinal mucosal barrier prevents macromolecules and pathogens from entering the circulatory stream. Tight junctions in this barrier are compromised in inflammatory bowel diseases, environmental enteropathy, and enteric dysfunction. Dual sugar absorption tests are a standard method for measuring gastrointestinal integrity, however, these are not clinically amenable. Herein, we report on a dual fluorophore system and fluorescence detection instrumentation for which gastrointestinal permeability is determined in a rat small bowel disease model from the longitudinal measured transdermal fluorescence of each fluorophore. This fluorophore technology enables a specimen-free, noninvasive, point-of-care gastrointestinal permeability measurement which should be translatable to human clinical studies.

Partially hydrolyzed guar gum alleviates small intestinal mucosal damage after massive small bowel resection along with changes in the intestinal microbiota

PurposeShort bowel syndrome is associated with intestinal mucosal inflammation and microbial dysbiosis, leading to intractable complications. Partially hydrolyzed guar gum (PHGG) has trophic and anti-inflammatory effects on the intestine. We investigated whether PHGG ameliorates small intestinal mucosal damage and alters the intestinal microbiota using a rat small bowel resection (SBR) model. MethodsSprague Dawley rats were divided into sham operation (Sham), Sham/PHGG, SBR, and SBR/PHGG groups. On day 21, all rats were euthanized. To assess small intestinal mucosal damage, the degeneration rate was morphometrically evaluated and immunohistochemically examined using anti-CD45 antibodies. Analyses of fecal microbiota using 16S rRNA and short-chain fatty acid production were also performed. ResultsThe mucosal degeneration rate was significantly higher in the SBR group than in the Sham or SBR/PHGG groups. The number of CD45-positive cells was significantly higher in the SBR group than in the Sham, Sham/PHGG, or SBR/PHGG groups. The relative abundance of family Lachnospiraceae was significantly higher in the SBR/PHGG group than in the SBR group. ConclusionsPHGG administration alleviated small intestinal mucosal damage which could be associated with modulation of the intestinal microbiota.

Human small bowel as model for poisoning with organophosphorus compounds

In previous experiments, human and rat small bowel samples have been successfully used to study the spasmolytic effect of (potential) therapeutics in carbamate-constricted bowel specimens. Additionally, transferability from rat to human data was shown in the previous study. In the present study, the effects of atropine, scopolamine, MB327, HI-6 as well as obidoxime were examined in organophosphorus-poisoned human small bowel specimens. All substances were tested with at least seven concentrations in samples previously exposed to the nerve agent sarin. Furthermore, the cholinesterase reactivation potential of all substances was investigated. The test substances displayed a spasmolytic effect allowing the calculation of dose-response curves and EC50s. The parasympatholytic compound scopolamine had the strongest relaxing effect (EC50 = 0.05 μM) followed by atropine (EC50 = 0.07 μM). HI-6 and obidoxime were capable to reactivate the sarin-inhibited cholinesterase activity in small bowel samples. Both substances restored AChE activity in a dose-dependent way, with HI-6 being more potent (HI-6 EC50 = 3.8 μM vs obidoxime EC50 = 197.8 μM). Summarizing, our isolated human small bowel setup is a suitable tool to investigate the smooth muscle relaxing effect of (candidate) therapeutics for organophosphorus compound poisoning i.e. sarin exposure in a complex 3D tissue model.

Adipose-derived mesenchymal stem cells suppress of acute rejection in small bowel transplantation.

Background/Aims:Adipose-derived mesenchymal stem cells (ADSCs) possess immunosuppressive activity and hold promise in autologous cell-based therapies. The aim of this study was to determine whether autologous ADSCs can improve outcomes in the rat small bowel transplantation (SBT) model.Materials and Methods:Allogeneic SBT followed by implantation of autologous ADSCs through the penile vein was conducted in Brown-Norway (BN) donor rats with Lewis (LEW) recipient rats infused with phosphate buffered solution as the control. Allograft and recipient peripheral blood were obtained. We assessed histopathology, apoptosis, cytokines, and regulatory T cells (Tregs). One-way analysis of variance was applied to assess the significance of the data.Results:It was found that ADSCs significantly reduced acute rejection and improved the allograft's survival rate. In addition, there were significantly fewer apoptotic cells in allograft mucosae in the ADSC group in comparison with the control group. Furthermore, levels of interleukin (IL)-10 and transforming growth factor-β1 were significantly elevated, whereas those of IL-2 and IL-17 levels were significantly reduced in the ADSC group when compared to the control group. Moreover, flow cytometry analysis revealed that there were significantly more peripheral Tregs after the infusion of ADSCs.Conclusions:These results demonstrate that implanted autologous ADSCs improve allogeneic small bowel allograft outcomes by attenuating the acute rejection and reducing inflammatory responses.

Recombinant Thrombomodulin (Solulin) Ameliorates Early Intestinal Radiation Toxicity in a Preclinical Rat Model.

Intestinal radiation toxicity occurs during and after abdominopelvic radiotherapy. Endothelial cells play a significant role in modulating radiation-induced intestinal damage. We demonstrated that the endothelial cell surface receptor thrombomodulin (TM), a protein with anticoagulant, anti-inflammatory and antioxidant properties, mitigates radiation-induced lethality in mice. The goal of this study was to determine whether recombinant TM (Solulin) can protect the intestine from toxicity in a clinically relevant rat model. A 4 cm loop of rat small bowel was exposed to fractionated 5 Gy X radiation for 9 consecutive days. The animals were randomly assigned to receive daily subcutaneous injections of vehicle or Solulin (3 mg/kg/day or 10 mg/kg/day) for 27 days starting 4 days before irradiation. Early intestinal injury was assessed two weeks after irradiation by quantitative histology, morphometry, immunohistochemistry and luminol bioluminescence imaging. Solulin treatment significantly ameliorated intestinal radiation injury, made evident by a decrease in myeloperoxidase (MPO) activity, transforming growth factor beta (TGF-β) immunoreactivity, collagen-I deposition, radiation injury score (RIS) and intestinal serosal thickening. These findings indicate the need for further development of Solulin as a prophylactic and/or therapeutic agent to mitigate radiation-induced intestinal damage.

One Size Fits All: Evaluation of the Transferability of a New "Learning" Histologic Image Analysis Application.

Quantitative analysis of histologic slides is of importance for pathology and also to address surgical questions. Recently, a novel application was developed for the automated quantification of whole-slide images. The aim of this study was to test and validate the underlying image analysis algorithm with respect to user friendliness, accuracy, and transferability to different histologic scenarios. The algorithm splits the images into tiles of a predetermined size and identifies the tissue class of each tile. In the training procedure, the user specifies example tiles of the different tissue classes. In the subsequent analysis procedure, the algorithm classifies each tile into the previously specified classes. User friendliness was evaluated by recording training time and testing reproducibility of the training procedure of users with different background. Accuracy was determined with respect to single and batch analysis. Transferability was demonstrated by analyzing tissue of different organs (rat liver, kidney, small bowel, and spleen) and with different stainings (glutamine synthetase and hematoxylin-eosin). Users of different educational background could apply the program efficiently after a short introduction. When analyzing images with similar properties, accuracy of >90% was reached in single images as well as in batch mode. We demonstrated that the novel application is user friendly and very accurate. With the "training" procedure the application can be adapted to novel image characteristics simply by giving examples of relevant tissue structures. Therefore, it is suitable for the fast and efficient analysis of high numbers of fully digitalized histologic sections, potentially allowing "high-throughput" quantitative "histomic" analysis.

A new method to measure intestinal secretion using fluorescein isothiocyanate-inulin in small bowel of rats

BackgroundSmall intestine ischemia can be seen in various conditions such as intestinal transplantation. To further understand the pathologic disruption in ischemia–reperfusion injury, we have developed a method to measure fluid changes in the intestinal lumen of rats. MethodsTwo 10-cm rat intestine segments were procured, connected to the terminal apertures of a perfusion device, and continuously infused with 3 mL of HEPES solution (control solution) containing 50 μM of fluorescein isothiocyanate (FITC)-inulin. The perfusion device consists of concentric chambers that contain the perfused bowel segments, which are maintained at 37°C via H2O bath. The individual chamber has four apertures as follows: two fill and/or drain the surrounding HEPES solution on the blood side of the tissue. The others provide flow of HEPES solution containing FITC-inulin through the lumens. The experimental intestine was infused with the same solution with 100 μM of Forskolin. A pump continuously circulated solutions at 6 mL/min. Samples were collected at 15-min intervals until 150 min and were measured by the nanoflourospectrometer. ResultsA mean of 6-μM decrease in the FITC-inulin concentration in the Forskolin-treated experimental intestine was observed in comparison with that in the control intestine. The FITC-inulin count dilution in the experimental intestine is a result of an increase of fluid secretion produced by the effect of Forskolin, with P values <0.0001. ConclusionsWe demonstrate that it is possible to measure luminal fluid changes over time using our new modified perfusion system along with FITC-inulin to allow real-time determinations of fluid and/or electrolyte movement along the small intestine.

Oxygen Insufflation in University of Wisconsin Solution Ameliorates Reperfusion Injury in Small Bowel after Cold Storage and Reperfusion.

BACKGROUND Results in small bowel transplantation are inferior compared to other solid organ transplantations, among other reasons, due to a specific vulnerability to ischemia/reperfusion injury. New strategies are needed to improve organ storage. Here we compare static cold storage in University of Wisconsin solution to storage supplemented with molecular oxygen gas insufflation. MATERIAL AND METHODS Rat small bowel was retrieved and either stored unoxygenated (UW) or oxygenated (UW+O2) for 18 h at 4°C. Biochemical parameters, mucosal function, Toll-like receptor upregulation, and parameters of structural integrity were evaluated following isolated reperfusion in vitro for 30 min at 37°C. RESULTS Oxygenation showed: ATP concentration was 82 times higher; lactate dehydrogenase release was continuously lower over 30 min; malondialdehyde, a final product of lipid peroxidation (UW+O2 vs. UW; 2.7±0.92 nmol/mL vs. 17.22±10.1 nmol/mL; P<0.05) and nitric oxide concentration (0.87±0.27 µmol/L vs. 2.17±0.29 µmol/L; P<0.001) were significantly lower; whereas mucosal functional integrity (galactose uptake) was better preserved (0.47±0.18 mg/dL vs. 0.35±0.05 mg/dL). Amelioration of tissue damage could be demonstrated by reduced apoptosis (3.3±1.2 AU vs. 28.4±10 AU; P>0.05), and preserved subcellular integrity. Toll-like receptors were significantly less upregulated (TLR2 0.32±0.1 vs. 2.1±1.5-fold and TLR4 1.53±1.14 vs. 11.79±5.4-fold; P<0.05). CONCLUSIONS Oxygenated storage is superior to standard storage in University of Wisconsin solution in terms of energetics, tissue damage, and mucosal integrity.

Reduction of acute rejection by bone marrow mesenchymal stem cells during rat small bowel transplantation.

BackgroundBone marrow mesenchymal stem cells (BMMSCs) have shown immunosuppressive activity in transplantation. This study was designed to determine whether BMMSCs could improve outcomes of small bowel transplantation in rats.MethodsHeterotopic small bowel transplantation was performed from Brown Norway to Lewis rats, followed by infusion of BMMSCs through the superficial dorsal veins of the penis. Controls included rats infused with normal saline (allogeneic control), isogeneically transplanted rats (BN-BN) and nontransplanted animals. The animals were sacrificed after 1, 5, 7 or 10 days. Small bowel histology and apoptosis, cytokine concentrations in serum and intestinal grafts, and numbers of T regulatory (Treg) cells were assessed at each time point.ResultsAcute cellular rejection occurred soon after transplantation and became aggravated over time in the allogeneic control rats, with increase in apoptosis, inflammatory response, and T helper (Th)1/Th2 and Th17/Treg-related cytokines. BMMSCs significantly attenuated acute cellular rejection, reduced apoptosis and suppressed the concentrations of interleukin (IL)-2, IL-6, IL-17, IL-23, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ while upregulating IL-10 and transforming growth factor (TGF)-β expression and increasing Treg levels.ConclusionBMMSCs improve the outcomes of allogeneic small bowel transplantation by attenuating the inflammatory response and acute cellular rejection. Treatment with BMMSCs may overcome acute cellular rejection in small bowel transplantation.

Anti-inflammatory Effects of Ischemic Preconditioning on Rat Small Bowel Allografts

IntroductionMinimizing the inflammatory events that follow intestinal transplantation may influence immediate graft function and improve outcome. Ischemic preconditioning (IPc) has been shown to ameliorate early inflammatory responses, and it may also attenuate the potentially damaging inflammation after intestinal transplantation. Herein, we examine the influence of intestinal IPc on inflammatory indices (tissue expression of ICAM-1, CD11a, and CD44 and serum levels of the soluble ICAM-1, sICAM-1) after heterotopic intestinal transplantation. MethodsLewis rats received full-length preconditioned or non-preconditioned Brown Norway intestinal allografts in the absence of immunosuppression. Preconditioned grafts were subjected to 1 cycle of 10 minutes of ischemia-reperfusion. Preconditioned and non-preconditioned isografts acted as controls. Blood was collected on alternate days post-transplant, and graft tissue harvested on sacrifice. ICAM-1, CD44, and CD11a expression was determined by immunohistochemistry, and the area of staining was quantified using image analysis. Serum soluble ICAM-1 levels were determined using an R&D Systems Quantikine enzyme immunoassay. Results(1) IPc ameliorated serum levels of sICAM-1 until severe rejection (day 7) overcame this down-regulation when compared to non-preconditioned allografts (day 3: 34,304 vs 40,479 pg/mL; day 5: 52,441 vs 61,593 pg/mL; day 7: 75,114 vs 73,309 pg/mL; day 9: 72,872 vs 76,314 pg/mL, respectively). (2) ICAM-1 expression was significantly lower in preconditioned allografts (1.02 vs 2.01 mm2). (3) CD44 tissue levels were also found to be lower in preconditioned allografts (0.86 vs 1.13 mm2). (4) There was a significant relationship between tissue ICAM-1 expression and serum levels of soluble ICAM-1 (P < .02). ConclusionsIPc improves inflammatory indices in the early stages following intestinal transplantation, and this might lead to a preserved cellular, architectural, and functional graft status. Furthermore, our results support the use of soluble ICAM-1 as a marker of endothelial activation, and thence of inflammation and developing rejection.

Selective evaluation of high density lipoprotein from mouse small intestine by an in situ perfusion technique

The small intestine (SI) is the second-greatest source of HDL in mice. However, the selective evaluation of SI-derived HDL (SI-HDL) has been difficult because even the origin of HDL obtained in vivo from the intestinal lymph duct of anesthetized rodents is doubtful. To shed light on this question, we have developed a novel in situ perfusion technique using surgically isolated mouse SI, with which the possible filtration of plasma HDL into the SI lymph duct can be prevented. With the developed method, we studied the characteristics of and mechanism for the production and regulation of SI-HDL. Nascent HDL particles were detected in SI lymph perfusates in WT mice, but not in ABCA1 KO mice. SI-HDL had a high protein content and was smaller than plasma HDL. SI-HDL was rich in TG and apo AIV compared with HDL in liver perfusates. SI-HDL was increased by high-fat diets and reduced in apo E KO mice. In conclusion, with our in situ perfusion model that enables the selective evaluation of SI-HDL, we demonstrated that ABCA1 plays an important role in intestinal HDL production, and SI-HDL is small, dense, rich in apo AIV, and regulated by nutritional and genetic factors.

The application of polymerized porcine hemoglobin (pPolyHb) in the rat small bowel preservation

Small bowel transplantation (SBTx) has become a standard clinical treatment for short bowel syndrome or irreversible intestinal function failure. Optimum preservation of the organ is essential for the success of transplantation. In this study, pPolyHb was used as an additive to hypertonic citrate adenine solution (HCA) to provide oxygen for rat small bowel transplant. Rat small bowels were preserved in HCA, HCA with pPolyHb, and University of Wisconsin solution (UW) for 12, 24, and 36 h, respectively. The results suggested that the preservation effect of HCA with pPolyHb was comparable with the UW solution, and more effective than the HCA solution.