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Büttner J, Blüthner E, Greif S, Kühl A, Elezkurtaj S, Ulrich J, Maasberg S, Jochum C, Tacke F, Pape UF. Predictive Potential of Biomarkers of Intestinal Barrier Function for Therapeutic Management with Teduglutide in Patients with Short Bowel Syndrome. Nutrients 2023; 15:4220. [PMID: 37836505 PMCID: PMC10574292 DOI: 10.3390/nu15194220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/12/2023] [Accepted: 09/27/2023] [Indexed: 10/15/2023] Open
Abstract
INTRODUCTION The human intestinal tract reacts to extensive resection with spontaneous intestinal adaptation. We analyzed whether gene expression analyses or intestinal permeability (IP) testing could provide biomarkers to describe regulation mechanisms in the intestinal barrier in short bowel syndrome (SBS) patients during adaptive response or treatment with the glucagon-like peptide-2 analog teduglutide. METHODS Relevant regions of the GLP-2 receptor gene were sequenced. Gene expression analyses and immunohistochemistry were performed from mucosal biopsies. IP was assessed using a carbohydrate oral ingestion test. RESULTS The study includes 59 SBS patients and 19 controls. Increases in gene expression with teduglutide were received for sucrase-isomaltase, sodium/glucose cotransporter 1, and calcium/calmodulin serine protein kinase. Mannitol recovery was decreased in SBS but elevated with teduglutide (Δ 40%), showed a positive correlation with remnant small bowel and an inverse correlation with parenteral support. CONCLUSIONS Biomarkers predicting clinical and functional features in human SBS are very limited. Altered specific gene expression was shown for genes involved in nutrient transport but not for genes controlling tight junctions. However, mannitol recovery proved useful in describing the absorptive capacity of the gut during adaptation and treatment with teduglutide.
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Affiliation(s)
- Janine Büttner
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Department of Hepatology and Gastroenterology, Campus Charité Mitte and Campus Virchow Klinikum, 10117 Berlin, Germany; (E.B.); (S.G.); (C.J.); (F.T.)
| | - Elisabeth Blüthner
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Department of Hepatology and Gastroenterology, Campus Charité Mitte and Campus Virchow Klinikum, 10117 Berlin, Germany; (E.B.); (S.G.); (C.J.); (F.T.)
- Berlin Institute of Health (BIH), 10178 Berlin, Germany
| | - Sophie Greif
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Department of Hepatology and Gastroenterology, Campus Charité Mitte and Campus Virchow Klinikum, 10117 Berlin, Germany; (E.B.); (S.G.); (C.J.); (F.T.)
| | - Anja Kühl
- iPATH.Berlin, Core Unit der Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt, Campus Benjamin Franklin, 12203 Berlin, Germany;
| | - Sefer Elezkurtaj
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Department of Pathology, Campus Mitte, 10117 Berlin, Germany;
| | - Jan Ulrich
- Department of Internal Medicine and Gastroenterology, Asklepios Klinik St. Georg, 20099 Hamburg, Germany; (J.U.); (S.M.)
| | - Sebastian Maasberg
- Department of Internal Medicine and Gastroenterology, Asklepios Klinik St. Georg, 20099 Hamburg, Germany; (J.U.); (S.M.)
| | - Christoph Jochum
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Department of Hepatology and Gastroenterology, Campus Charité Mitte and Campus Virchow Klinikum, 10117 Berlin, Germany; (E.B.); (S.G.); (C.J.); (F.T.)
| | - Frank Tacke
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Department of Hepatology and Gastroenterology, Campus Charité Mitte and Campus Virchow Klinikum, 10117 Berlin, Germany; (E.B.); (S.G.); (C.J.); (F.T.)
| | - Ulrich-Frank Pape
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Department of Hepatology and Gastroenterology, Campus Charité Mitte and Campus Virchow Klinikum, 10117 Berlin, Germany; (E.B.); (S.G.); (C.J.); (F.T.)
- Department of Internal Medicine and Gastroenterology, Asklepios Klinik St. Georg, 20099 Hamburg, Germany; (J.U.); (S.M.)
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Zheng R, Valicherla GR, Zhang J, Nuttall J, Silvera P, Marshall LJ, Empey PE, Rohan LC. Transport and Permeation Properties of Dapivirine: Understanding Potential Drug-Drug Interactions. Pharmaceutics 2022; 14:1948. [PMID: 36145696 PMCID: PMC9501983 DOI: 10.3390/pharmaceutics14091948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/09/2022] [Accepted: 09/12/2022] [Indexed: 11/16/2022] Open
Abstract
The dapivirine (DPV) vaginal ring was developed by the nonprofit International Partnership for Microbicides (IPM) for reducing the risk of HIV infection. A clinical study (IPM 028) showed that concomitant use of the DPV ring and miconazole (MIC) altered DPV pharmacokinetic profile. In this work, we investigated whether or not DPV transport and permeation contributed to the observed DPV-MIC interaction. Our study evaluated the interaction between DPV and several transporters that are highly expressed in the human female reproductive tract, including MRP1, MRP4, P-gp, BCRP, and ENT1, using vesicular and cellular systems. We also evaluated the impact of DPV/MIC on cellular tight junctions by monitoring transepithelial electrical resistance with the Ussing chamber. Lastly, we evaluated the effect of MIC on DPV permeability across human cervical tissue. Our findings showed that DPV was not a substrate of MRP1, MRP4, P-gp, BCRP, or ENT1 transporters. Additionally, DPV did not inhibit the activity of these transporters. DPV, MIC, and their combination also did not disrupt cellular tight junctions. MIC did not affect DPV tissue permeability but significantly reduced DPV tissue levels. Therefore, our results suggest that the DPV-MIC interaction is not due to these five transporters, altered tight junction integrity, or altered tissue permeability.
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Affiliation(s)
- Ruohui Zheng
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Magee-Womens Research Institute, Pittsburgh, PA 15213, USA
| | - Guru R. Valicherla
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Magee-Womens Research Institute, Pittsburgh, PA 15213, USA
| | - Junmei Zhang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Magee-Womens Research Institute, Pittsburgh, PA 15213, USA
| | - Jeremy Nuttall
- International Partnership for Microbicides, Silver Spring, MD 20910, USA
| | - Peter Silvera
- Advanced Bioscience Laboratories, Rockville, MD 20850, USA
| | - Leslie J. Marshall
- Preclinical Microbicide and Prevention Research Branch, Prevention Sciences Program, Division of AIDS, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Philip E. Empey
- Department of Pharmacy & Therapeutics, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Lisa C. Rohan
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Magee-Womens Research Institute, Pittsburgh, PA 15213, USA
- Department of Obstetrics, Gynecology, Reproductive Sciences, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
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Vanuytsel T, Tack J, Farre R. The Role of Intestinal Permeability in Gastrointestinal Disorders and Current Methods of Evaluation. Front Nutr 2021; 8:717925. [PMID: 34513903 PMCID: PMC8427160 DOI: 10.3389/fnut.2021.717925] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/04/2021] [Indexed: 12/12/2022] Open
Abstract
An increased intestinal permeability has been described in various gastrointestinal and non-gastrointestinal disorders. Nevertheless, the concept and definition of intestinal permeability is relatively broad and includes not only an altered paracellular route, regulated by tight junction proteins, but also the transcellular route involving membrane transporters and channels, and endocytic mechanisms. Paracellular intestinal permeability can be assessed in vivo by using different molecules (e.g., sugars, polyethylene glycols, 51Cr-EDTA) and ex vivo in Ussing chambers combining electrophysiology and probes of different molecular sizes. The latter is still the gold standard technique for assessing the epithelial barrier function, whereas in vivo techniques, including putative blood biomarkers such as intestinal fatty acid-binding protein and zonulin, are broadly used despite limitations. In the second part of the review, the current evidence of the role of impaired barrier function in the pathophysiology of selected gastrointestinal and liver diseases is discussed. Celiac disease is one of the conditions with the best evidence for impaired barrier function playing a crucial role with zonulin as its proposed regulator. Increased permeability is clearly present in inflammatory bowel disease, but the question of whether this is a primary event or a consequence of inflammation remains unsolved. The gut-liver axis with a crucial role in impaired intestinal barrier function is increasingly recognized in chronic alcoholic and metabolic liver disease. Finally, the current evidence does not support an important role for increased permeability in bile acid diarrhea.
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Affiliation(s)
- Tim Vanuytsel
- Department of Chronic Diseases, Translational Research Center for Gastrointestinal Disorders, Metabolism and Ageing, Catholic University Leuven, Leuven, Belgium.,Division of Gastroenterology and Hepatology, Leuven University Hospital, Leuven, Belgium
| | - Jan Tack
- Department of Chronic Diseases, Translational Research Center for Gastrointestinal Disorders, Metabolism and Ageing, Catholic University Leuven, Leuven, Belgium.,Division of Gastroenterology and Hepatology, Leuven University Hospital, Leuven, Belgium
| | - Ricard Farre
- Department of Chronic Diseases, Translational Research Center for Gastrointestinal Disorders, Metabolism and Ageing, Catholic University Leuven, Leuven, Belgium
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Celi P, Verlhac V, Pérez Calvo E, Schmeisser J, Kluenter AM. Biomarkers of gastrointestinal functionality in animal nutrition and health. Anim Feed Sci Technol 2019. [DOI: 10.1016/j.anifeedsci.2018.07.012] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Dutton JS, Hinman SS, Kim R, Wang Y, Allbritton NL. Primary Cell-Derived Intestinal Models: Recapitulating Physiology. Trends Biotechnol 2018; 37:744-760. [PMID: 30591184 DOI: 10.1016/j.tibtech.2018.12.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 12/02/2018] [Accepted: 12/03/2018] [Indexed: 02/07/2023]
Abstract
The development of physiologically relevant intestinal models fueled by breakthroughs in primary cell-culture methods has enabled successful recapitulation of key features of intestinal physiology. These advances, paired with engineering methods, for example incorporating chemical gradients or physical forces across the tissues, have yielded ever more sophisticated systems that enhance our understanding of the impact of the host microbiome on human physiology as well as on the genesis of intestinal diseases such as inflammatory bowel disease and colon cancer. In this review we highlight recent advances in the development and usage of primary cell-derived intestinal models incorporating monolayers, organoids, microengineered platforms, and macrostructured systems, and discuss the expected directions of the field.
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Affiliation(s)
- Johanna S Dutton
- Joint Department of Biomedical Engineering, University of North Carolina, Chapel Hill, and North Carolina State University, Raleigh, NC, USA
| | - Samuel S Hinman
- Department of Chemistry, University of North Carolina, Chapel Hill, NC, USA
| | - Raehyun Kim
- Joint Department of Biomedical Engineering, University of North Carolina, Chapel Hill, and North Carolina State University, Raleigh, NC, USA
| | - Yuli Wang
- Department of Chemistry, University of North Carolina, Chapel Hill, NC, USA
| | - Nancy L Allbritton
- Joint Department of Biomedical Engineering, University of North Carolina, Chapel Hill, and North Carolina State University, Raleigh, NC, USA; Department of Chemistry, University of North Carolina, Chapel Hill, NC, USA.
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6
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Kumar D, Pandey G, Bansal D, Rawat A, Kumar U, Dubey D, Guleria A, Saraswat VA. NMR-based urinary profiling of lactulose/mannitol ratio used to assess the altered intestinal permeability in acute on chronic liver failure (ACLF) patients. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2017; 55:289-296. [PMID: 27623987 DOI: 10.1002/mrc.4525] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 07/10/2016] [Accepted: 09/09/2016] [Indexed: 06/06/2023]
Abstract
The article presents a simplified NMR-based protocol for urinary profiling of lactulose/mannitol ratio (LMR) and demonstrates here its utility to assess increased intestinal permeability (IP) in patients with acute on chronic liver failure (ACLF). ACLF is a serious clinical complication associated with chronic liver disease (cirrhosis). The major risk factor in its development is increased IP ('leaky gut'), which has been linked to disease progression and to infectious complications. However, IP has seldom been investigated in patients with ACLF, even though patients frequently report gastrointestinal disorders and associated complications. To this end, we first optimized the NMR-based targeted profiling of urinary metabolites (i.e. actulose, mannitol, and creatinine) and subsequently used this resulted protocol (a) first to evaluate the altered IP in ACLF patients and then (b) to explore its utility for monitoring the treatment response in these patients. The normal profiles were obtained for 7 age and sex matched healthy volunteers. The results revealed that the urinary LMR excretion was significantly higher in ACLF patients compared to normal controls (median ~0.7, range (0.12-2.84), vs median ~0.11, range (0.02-0.28), p < 0.001) suggesting that the ACLF patients' exhibit altered IP. However, the LMR excretion in six clinically improved follow-up ACLF patients was comparable to normal controls indicating restored IP after the treatment. The protocol-as demonstrated here with ACLF-is equally applicable for evaluating IP or mucosal barrier function in other intestinal disorders with reasonable sensitivity and specificity, highlighting its general utility. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Dinesh Kumar
- Centre of Biomedical Research, Sanjay Gandhi Post Graduate Institute of Medical Science, Lucknow, India
| | - Gaurav Pandey
- Department of Gastroenterology, Sanjay Gandhi Post Graduate Institute of Medical Science, Lucknow, India
| | - Deepak Bansal
- Department of Gastroenterology, Sanjay Gandhi Post Graduate Institute of Medical Science, Lucknow, India
| | - Atul Rawat
- Centre of Biomedical Research, Sanjay Gandhi Post Graduate Institute of Medical Science, Lucknow, India
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Lucknow, India
| | - Umesh Kumar
- Centre of Biomedical Research, Sanjay Gandhi Post Graduate Institute of Medical Science, Lucknow, India
| | - Durgesh Dubey
- Centre of Biomedical Research, Sanjay Gandhi Post Graduate Institute of Medical Science, Lucknow, India
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Lucknow, India
| | - Anupam Guleria
- Centre of Biomedical Research, Sanjay Gandhi Post Graduate Institute of Medical Science, Lucknow, India
| | - Vivek Anand Saraswat
- Department of Gastroenterology, Sanjay Gandhi Post Graduate Institute of Medical Science, Lucknow, India
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Lentle RG, Sequeira IR, Hardacre AK, Reynolds G. A method for assessing real time rates of dissolution and absorption of carbohydrate and other food matrices in human subjects. Food Funct 2016; 7:2820-32. [PMID: 27228950 DOI: 10.1039/c6fo00406g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We prepared pasta of differing physical dimensions but identical chemical composition that contained two monosaccharide probes (lactulose and mannitol) that are absorbed passively and promptly excreted in urine. We showed that the rates of their liberation from the pasta under simulated gastric and small intestinal conditions largely depended upon the rate of digestion of the starchy matrix. We showed, in 20 female subjects, that excretion of mannitol was slower from the pasta with the larger particle size. Hence, after consumption of either the powdered pasta or the simple solution of probe sugars, the mass of mannitol excreted between 1 and 2½ hours was greater than that excreted between 2½ and 4 hours. However these masses did not differ significantly after consumption of the pasta pellets. These differences were not reflected in the concurrent patterns of variation in either serum glucose or insulin taken over 120 minutes, their levels being similar for pasta pellets and powder with their peak values occurring synchronously during the first hour. Hence feeding test foods impregnated with lactulose and mannitol probes provided a reproducible and practical means of assessing the timing of digestion of the carbohydrate matrix and showed that this was more protracted than suggested by post prandial glucose levels. Further, the transit times calculated on a basis of the ratios of the two marker sugars could identify that the prolongation of digestion of larger particles was not accompanied by retention of digesta in particular segments of the gut.
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Affiliation(s)
- R G Lentle
- Massey Institute of Food Science and Technology, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand
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A novel method for imaging sites of paracellular passage of macromolecules in epithelial sheets. J Control Release 2016; 229:70-79. [PMID: 26995760 DOI: 10.1016/j.jconrel.2016.03.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 03/09/2016] [Accepted: 03/14/2016] [Indexed: 12/16/2022]
Abstract
Understanding the dynamics of intestinal barrier function is key to elucidating oral delivery routes of therapeutics as well as to understanding various diseases that involve the mucosal immune system. Passage of macromolecules across barrier-forming epithelia is classically analyzed by means of various tracer flux measurements. This approach averages over contributions from many cells and lacks labeling of passage-sites. Thus, abundance and nature of involved cells have remained unidentified. We present a novel method that allowed for optical analysis of passage of various macromolecules on large-scale and single-cell level. To achieve tracking of passage loci in epithelia at submicrometer resolution we used biotinylated and fluorescent macromolecules that bind to basolateral membranes pre-labeled with cell-adherent avidin. We applied this method to epithelial cell lines and isolated mucosae in order to 3-dimensionally determine barrier leak properties over time. Tracer passage was found in all epithelia examined. However, it was infrequent, strikingly inhomogeneous, depended on culture duration and tightness of the monolayer. Stimulating passage with barrier-perturbing agents increased the number of leaks exposition time-dependently in cell lines and explanted mucosae. After stepwise opening of the paracellular passage pathway, integrated tracer-signal measured by our assay strictly correlated to simultaneously performed standard fluxes. Thus, our assay allows for the study of transepithelial macromolecule passage in various physiological and pathological conditions.
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Price ER, Rott KH, Caviedes-Vidal E, Karasov WH. Claudin gene expression patterns do not associate with interspecific differences in paracellular nutrient absorption. Comp Biochem Physiol B Biochem Mol Biol 2016; 191:36-45. [DOI: 10.1016/j.cbpb.2015.09.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 09/08/2015] [Accepted: 09/09/2015] [Indexed: 11/27/2022]
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De Santis S, Cavalcanti E, Mastronardi M, Jirillo E, Chieppa M. Nutritional Keys for Intestinal Barrier Modulation. Front Immunol 2015; 6:612. [PMID: 26697008 PMCID: PMC4670985 DOI: 10.3389/fimmu.2015.00612] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 11/22/2015] [Indexed: 12/14/2022] Open
Abstract
The intestinal tract represents the largest interface between the external environment and the human body. Nutrient uptake mostly happens in the intestinal tract, where the epithelial surface is constantly exposed to dietary antigens. Since inflammatory response toward these antigens may be deleterious for the host, a plethora of protective mechanisms take place to avoid or attenuate local damage. For instance, the intestinal barrier is able to elicit a dynamic response that either promotes or impairs luminal antigens adhesion and crossing. Regulation of intestinal barrier is crucial to control intestinal permeability whose increase is associated with chronic inflammatory conditions. The cross talk among bacteria, immune, and dietary factors is able to modulate the mucosal barrier function, as well as the intestinal permeability. Several nutritional products have recently been proposed as regulators of the epithelial barrier, even if their effects are in part contradictory. At the same time, the metabolic function of the microbiota generates new products with different effects based on the dietary content. Besides conventional treatments, novel therapies based on complementary nutrients are now growing. Fecal therapy has been recently used for the clinical treatment of refractory Clostridium difficile infection instead of the classical antibiotic therapy. In the present review, we will outline the epithelial response to nutritional components derived from dietary intake and microbial fermentation focusing on the consequent effects on the integrity of the epithelial barrier.
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Affiliation(s)
- Stefania De Santis
- Laboratory of Experimental Immunopathology, IRCCS "De Bellis" , Castellana Grotte , Italy
| | - Elisabetta Cavalcanti
- Laboratory of Experimental Immunopathology, IRCCS "De Bellis" , Castellana Grotte , Italy
| | - Mauro Mastronardi
- Department of Gastroenterology, IRCCS "De Bellis" , Castellana Grotte , Italy
| | - Emilio Jirillo
- Department of Basic Medical Sciences, Neuroscience and Sensory Organs, University of Bari , Bari , Italy
| | - Marcello Chieppa
- Laboratory of Experimental Immunopathology, IRCCS "De Bellis" , Castellana Grotte , Italy ; Istituto Comprensivo Bregante-Volta , Monopoli , Italy
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Porcine models of digestive disease: the future of large animal translational research. Transl Res 2015; 166:12-27. [PMID: 25655839 PMCID: PMC4458388 DOI: 10.1016/j.trsl.2015.01.004] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 01/03/2015] [Accepted: 01/07/2015] [Indexed: 12/14/2022]
Abstract
There is increasing interest in nonrodent translational models for the study of human disease. The pig, in particular, serves as a useful animal model for the study of pathophysiological conditions relevant to the human intestine. This review assesses currently used porcine models of gastrointestinal physiology and disease and provides a rationale for the use of these models for future translational studies. The pig has proven its utility for the study of fundamental disease conditions such as ischemia-reperfusion injury, stress-induced intestinal dysfunction, and short bowel syndrome. Pigs have also shown great promise for the study of intestinal barrier function, surgical tissue manipulation and intervention, as well as biomaterial implantation and tissue transplantation. Advantages of pig models highlighted by these studies include the physiological similarity to human intestine and mechanisms of human disease. Emerging future directions for porcine models of human disease include the fields of transgenics and stem cell biology, with exciting implications for regenerative medicine.
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Kosek M, Guerrant RL, Kang G, Bhutta Z, Yori PP, Gratz J, Gottlieb M, Lang D, Lee G, Haque R, Mason CJ, Ahmed T, Lima A, Petri WA, Houpt E, Olortegui MP, Seidman JC, Mduma E, Samie A, Babji S. Assessment of environmental enteropathy in the MAL-ED cohort study: theoretical and analytic framework. Clin Infect Dis 2015; 59 Suppl 4:S239-47. [PMID: 25305293 DOI: 10.1093/cid/ciu457] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Individuals in the developing world live in conditions of intense exposure to enteric pathogens due to suboptimal water and sanitation. These environmental conditions lead to alterations in intestinal structure, function, and local and systemic immune activation that are collectively referred to as environmental enteropathy (EE). This condition, although poorly defined, is likely to be exacerbated by undernutrition as well as being responsible for permanent growth deficits acquired in early childhood, vaccine failure, and loss of human potential. This article addresses the underlying theoretical and analytical frameworks informing the methodology proposed by the Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) cohort study to define and quantify the burden of disease caused by EE within a multisite cohort. Additionally, we will discuss efforts to improve, standardize, and harmonize laboratory practices within the MAL-ED Network. These efforts will address current limitations in the understanding of EE and its burden on children in the developing world.
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Affiliation(s)
- Margaret Kosek
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland Asociación Benéfica PRISMA, Iquitos, Peru
| | | | | | - Zulfiqar Bhutta
- Department of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Pablo Peñataro Yori
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland Asociación Benéfica PRISMA, Iquitos, Peru
| | - Jean Gratz
- Center for Global Health, University of Virginia, Charlottesville
| | | | - Dennis Lang
- Foundation of the National Institutes of Health Fogarty International Center, National Institutes of Health, Bethesda, Maryland
| | - Gwenyth Lee
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland Asociación Benéfica PRISMA, Iquitos, Peru
| | | | - Carl J Mason
- Walter Reed/Armed Forces Research Institute of Medical Sciences Research Unit, Bangkok, Thailand
| | - Tahmeed Ahmed
- Center for Vaccine Sciences, iccdr,b, Dhaka, Bangladesh
| | - Aldo Lima
- Federal University of Ceará, Fortaleza, Brazil
| | - William A Petri
- Center for Global Health, University of Virginia, Charlottesville
| | - Eric Houpt
- Center for Global Health, University of Virginia, Charlottesville
| | - Maribel Paredes Olortegui
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland Asociación Benéfica PRISMA, Iquitos, Peru
| | - Jessica C Seidman
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland
| | | | - Amidou Samie
- University of Venda, Limpopo Province, South Africa
| | - Sudhir Babji
- Christian Medical College, Vellore, Tamil Nadu, India
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Sequeira IR, Kruger MC, Hurst RD, Lentle RG. Ascorbic Acid may Exacerbate Aspirin-Induced Increase in Intestinal Permeability. Basic Clin Pharmacol Toxicol 2015; 117:195-203. [PMID: 25641731 DOI: 10.1111/bcpt.12388] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 01/20/2015] [Indexed: 12/23/2022]
Abstract
Ascorbic acid in combination with aspirin has been used to prevent aspirin-induced oxidative GI damage. We aimed to determine whether ascorbic acid reduces or prevents aspirin-induced changes in intestinal permeability over a 6-hr period using saccharidic probes mannitol and lactulose. The effects of administration of 600 mg aspirin alone, 500 mg ascorbic acid alone and simultaneous dosage of both agents were compared in a cross-over study in 28 healthy female volunteers. These effects were also compared with that of a placebo. The ability of ascorbic acid to mitigate the effects of aspirin when administered either half an hour before or after dosage with aspirin was also assessed in 19 healthy female volunteers. The excretion of lactulose over the 6-hr period was augmented after consumption of either aspirin or ascorbic acid compared with that after consumption of placebo. Dosage with ascorbic acid alone augmented the excretion of lactulose more than did aspirin alone. Simultaneous dosage with both agents augmented the excretion of lactulose in an additive manner. The timing of dosage with ascorbic acid in relation to that with aspirin had no significant effect on the excretion of the two sugars. These findings indicate that ascorbic acid does not prevent aspirin-induced increase in gut permeability rather that both agents augment it to a similar extent. The additive effect on simultaneous dosage with both agents in augmenting the absorption of lactulose suggests that each influences paracellular permeability by different pathways.
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Affiliation(s)
- Ivana R Sequeira
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand
| | - Marlena C Kruger
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand
| | - Roger D Hurst
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North, New Zealand
| | - Roger G Lentle
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand
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Gonzalez LM, Moeser AJ, Blikslager AT. Animal models of ischemia-reperfusion-induced intestinal injury: progress and promise for translational research. Am J Physiol Gastrointest Liver Physiol 2015; 308:G63-75. [PMID: 25414098 PMCID: PMC4297854 DOI: 10.1152/ajpgi.00112.2013] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Research in the field of ischemia-reperfusion injury continues to be plagued by the inability to translate research findings to clinically useful therapies. This may in part relate to the complexity of disease processes that result in intestinal ischemia but may also result from inappropriate research model selection. Research animal models have been integral to the study of ischemia-reperfusion-induced intestinal injury. However, the clinical conditions that compromise intestinal blood flow in clinical patients ranges widely from primary intestinal disease to processes secondary to distant organ failure and generalized systemic disease. Thus models that closely resemble human pathology in clinical conditions as disparate as volvulus, shock, and necrotizing enterocolitis are likely to give the greatest opportunity to understand mechanisms of ischemia that may ultimately translate to patient care. Furthermore, conditions that result in varying levels of ischemia may be further complicated by the reperfusion of blood to tissues that, in some cases, further exacerbates injury. This review assesses animal models of ischemia-reperfusion injury as well as the knowledge that has been derived from each to aid selection of appropriate research models. In addition, a discussion of the future of intestinal ischemia-reperfusion research is provided to place some context on the areas likely to provide the greatest benefit from continued research of ischemia-reperfusion injury.
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Affiliation(s)
- Liara M. Gonzalez
- 1Department of Clinical Sciences, Center for Comparative Medicine and Translational Research, North Carolina State University, Raleigh, North Carolina; and
| | - Adam J. Moeser
- 2Department of Population Health and Pathobiology, Center for Comparative Medicine and Translational Research, North Carolina State University, Raleigh, North Carolina
| | - Anthony T. Blikslager
- 1Department of Clinical Sciences, Center for Comparative Medicine and Translational Research, North Carolina State University, Raleigh, North Carolina; and
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Price ER, Rott KH, Caviedes-Vidal E, Karasov WH. Paracellular nutrient absorption is higher in bats than rodents: integrating from intact animals to the molecular level. ACTA ACUST UNITED AC 2014; 217:3483-92. [PMID: 25063860 DOI: 10.1242/jeb.105619] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Flying vertebrates have been hypothesized to rely heavily on paracellular absorption of nutrients to compensate for having smaller intestines than non-flyers. We tested this hypothesis in an insectivorous bat (Myotis lucifugus) and two insect-eating rodents (Onychomys leucogaster and Peromyscus leucopus). In intact animals, the fractional absorption of orally dosed l-arabinose (Mr 150) was 82% in M. lucifugus, which was more than twice that of the rodents. Absorption of creatinine (Mr 113) was greater than 50% for all species and did not differ between M. lucifugus and the rodents. We also conducted intestinal luminal perfusions on anesthetized animals. Absorption of l-arabinose per nominal surface area in M. lucifugus was nearly double that of the rodents, while absorption of creatinine was not different among species. Using an everted sleeve preparation, we demonstrated that high concentrations of l-arabinose and creatinine did not inhibit their own uptake, validating their use as passive, paracellular probes. Histological measurements indicated that M. lucifugus has more cells, and presumably more tight junctions, per nominal surface area than P. leucopus. This seems unlikely to explain entirely the higher absorption of l-arabinose in M. lucifugus during perfusions, because l-arabinose absorption normalized to the number of enterocytes was still double that of P. leucopus. As an alternative, we investigated tight junction gene expression. M. lucifugus had higher expression of claudin-1 and claudin-15, and lower expression of claudin-2 relative to P. leucopus. Expression of claudin-7 and occludin did not differ among species. Taken together, our results support the hypothesis that bats have evolved higher paracellular nutrient absorption than non-flying animals, and that this phenomenon might be driven by both histological characteristics and differences in tight junction gene expression.
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Affiliation(s)
- Edwin R Price
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Katherine H Rott
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Enrique Caviedes-Vidal
- Departamento de Bioquímica y Ciencias Biológicas y Laboratorio de Biología 'Professor E. Caviedes Codelia', Universidad Nacional de San Luis, 5700 San Luis, Argentina Laboratorio de Biología Integrativa, Instituto Multidisciplinario de Investigaciones Biológicas de San Luis, Consejo Nacional de Investigaciones Científicas y Técnicas, 5700 San Luis, Argentina
| | - William H Karasov
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA
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Sjögren E, Abrahamsson B, Augustijns P, Becker D, Bolger MB, Brewster M, Brouwers J, Flanagan T, Harwood M, Heinen C, Holm R, Juretschke HP, Kubbinga M, Lindahl A, Lukacova V, Münster U, Neuhoff S, Nguyen MA, Peer AV, Reppas C, Hodjegan AR, Tannergren C, Weitschies W, Wilson C, Zane P, Lennernäs H, Langguth P. In vivo methods for drug absorption – Comparative physiologies, model selection, correlations with in vitro methods (IVIVC), and applications for formulation/API/excipient characterization including food effects. Eur J Pharm Sci 2014; 57:99-151. [DOI: 10.1016/j.ejps.2014.02.010] [Citation(s) in RCA: 196] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 02/15/2014] [Accepted: 02/17/2014] [Indexed: 01/11/2023]
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Sequeira IR, Lentle RG, Kruger MC, Hurst RD. Differential trafficking of saccharidic probes following aspirin in clinical tests of intestinal permeability in young healthy women. Clin Exp Pharmacol Physiol 2014; 41:107-17. [DOI: 10.1111/1440-1681.12163] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 07/31/2013] [Accepted: 08/14/2013] [Indexed: 12/19/2022]
Affiliation(s)
- Ivana R Sequeira
- Institute of Food, Nutrition and Human Health; Massey University; Palmerston North New Zealand
| | - Roger G Lentle
- Institute of Food, Nutrition and Human Health; Massey University; Palmerston North New Zealand
| | - Marlena C Kruger
- Institute of Food, Nutrition and Human Health; Massey University; Palmerston North New Zealand
| | - Roger D Hurst
- The New Zealand Institute for Plant & Food Research Ltd; Palmerston North New Zealand
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Sigalet DL, Kravarusic D, Butzner D, Hartmann B, Holst JJ, Meddings J. A pilot study examining the relationship among Crohn disease activity, glucagon-like peptide-2 signalling and intestinal function in pediatric patients. CANADIAN JOURNAL OF GASTROENTEROLOGY = JOURNAL CANADIEN DE GASTROENTEROLOGIE 2013; 27:587-92. [PMID: 24106731 PMCID: PMC3805340 DOI: 10.1155/2013/460958] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 06/02/2013] [Indexed: 12/19/2022]
Abstract
UNLABELLED BACKGROUND⁄ OBJECTIVES The relationship between the enteroendocrine hormone glucagon-like peptide 2 (GLP-2) and intestinal inflammation is unclear. GLP-2 promotes mucosal growth, decreases permeability and reduces inflammation in the intestine; physiological stimulation of GLP-2 release is triggered by nutrient contact. The authors hypothesized that ileal Crohn disease (CD) affects GLP-2 release. METHODS With ethics board approval, pediatric patients hospitalized with CD were studied; controls were recruited from local schools. Inclusion criteria were endoscopy-confirmed CD (primarily of the small intestine) with a disease activity index >150. Fasting and postprandial GLP-2 levels and quantitative urinary recovery of orally administered 3-O-methyl-glucose (active transport) and lactulose⁄mannitol (passive) were quantified during the acute and remission phases. RESULTS Seven patients (mean [± SD] age 15.3 ± 1.3 years) and 10 controls (10.3 ± 1.6 years) were studied. In patients with active disease, fasting levels of GLP-2 remained stable but postprandial levels were reduced. Patients with active disease exhibited reduced glucose absorption and increased lactulose⁄mannitol recovery; all normalized with disease remission. The change in the lactulose⁄mannitol ratio was due to both reduced lactulose and increased mannitol absorption. CONCLUSIONS These findings suggest that pediatric patients with acute ileal CD have decreased postprandial GLP-2 release, reduced glucose absorption and increased intestinal permeability. Healing of CD resulted in normalization of postprandial GLP-2 release and mucosal functioning (nutrient absorption and permeability), the latter due to an increase in mucosal surface area. These findings have implications for the use of GLP-2 and feeding strategies as a therapy in CD patients; further studies of the effects of inflammation and the GLP-2 axis are recommended.
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Affiliation(s)
- David L Sigalet
- Gastrointestinal Research Group, Snyder Institute of Infection, Immunity and Inflammation, Deparment of Surgery, Faculty of Medicine, University of Calgary, Calgary, Alberta
| | | | - Decker Butzner
- Gastrointestinal Research Group, Snyder Institute of Infection, Immunity and Inflammation, Deparment of Surgery, Faculty of Medicine, University of Calgary, Calgary, Alberta
| | | | - Jens J Holst
- Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Jon Meddings
- Gastrointestinal Research Group, Snyder Institute of Infection, Immunity and Inflammation, Deparment of Surgery, Faculty of Medicine, University of Calgary, Calgary, Alberta
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Furmanski BD, Hu S, Fujita KI, Li L, Gibson AA, Janke LJ, Williams RT, Schuetz JD, Sparreboom A, Baker SD. Contribution of ABCC4-mediated gastric transport to the absorption and efficacy of dasatinib. Clin Cancer Res 2013; 19:4359-4370. [PMID: 23794731 DOI: 10.1158/1078-0432.ccr-13-0980] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Several oral multikinase inhibitors are known to interact in vitro with the human ATP-binding cassette transporter ABCC4 (MRP4), but the in vivo relevance of this interaction remains poorly understood. We hypothesized that host ABCC4 activity may influence the pharmacokinetic profile of dasatinib and subsequently affect its antitumor properties. EXPERIMENTAL DESIGN Transport of dasatinib was studied in cells transfected with human ABCC4 or the ortholog mouse transporter, Abcc4. Pharmacokinetic studies were done in wild-type and Abcc4-null mice. The influence of Abcc4 deficiency on dasatinib efficacy was evaluated in a model of Ph(+) acute lymphoblastic leukemia by injection of luciferase-positive, p185(BCR-ABL)-expressing Arf(-/-) pre-B cells. RESULTS Dasatinib accumulation was significantly changed in cells overexpressing ABCC4 or Abcc4 compared with control cells (P < 0.001). Deficiency of Abcc4 in vivo was associated with a 1.75-fold decrease in systemic exposure to oral dasatinib, but had no influence on the pharmacokinetics of intravenous dasatinib. Abcc4 was found to be highly expressed in the stomach, and dasatinib efflux from isolated mouse stomachs ex vivo was impaired by Abcc4 deficiency (P < 0.01), without any detectable changes in gastric pH. Abcc4-null mice receiving dasatinib had an increase in leukemic burden, based on bioluminescence imaging, and decreased overall survival compared with wild-type mice (P = 0.048). CONCLUSIONS This study suggests that Abcc4 in the stomach facilitates the oral absorption of dasatinib, and it possibly plays a similar role for other orally administered substrates, such as acetylsalicylic acid. This phenomenon also provides a mechanistic explanation for the malabsorption of certain drugs following gastric resection.
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Affiliation(s)
- Brian D Furmanski
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Shuiying Hu
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Ken-Ichi Fujita
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Lie Li
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Alice A Gibson
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Laura J Janke
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Richard T Williams
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - John D Schuetz
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Alex Sparreboom
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Sharyn D Baker
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee
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Benjamin J, Singla V, Arora I, Sood S, Joshi YK. Intestinal permeability and complications in liver cirrhosis: A prospective cohort study. Hepatol Res 2013; 43:200-7. [PMID: 22726344 DOI: 10.1111/j.1872-034x.2012.01054.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
AIM Increased intestinal permeability (IP) has been implicated as an important factor for bacterial translocation (BT), leading to bacteremia and endotoxemia, resulting in various septic complications, variceal bleeding (VB), hepatic encephalopathy (HE), hepatorenal syndrome (HRS) and death in patients with liver cirrhosis (LC). This study was planned to assess IP in patients with LC and follow them for the occurrence of complications. METHODS Patients with Child B and C cirrhosis without a history of disease-related complications were followed up for 6 months. IP was measured by lactulose and mannitol excretion ratio (LMR) in patients and 50 healthy controls (HC). Serum endotoxin levels were also assessed in 48 patients and 20 HC. RESULTS Eighty patients (74 male), 41 (51.3%) Child B and 56 (70%) Child C, with a mean age of 40.7 ± 9.8 years were enrolled. IP was increased in 28 (35%) patients. LMR of patients was higher than HC (patients vs HC = 0.0238 [0.0010-1.557] vs 0.0166 [0.0018-0.720]; P = 0.007]. No significant difference was seen in the LMR of patients among various Child classes and etiologies. Serum endotoxin levels (GMU/mL) were higher in patients than HC (patients vs HC = 1.42 [0.68-2.13] vs 0.994 [0.067-1.382]; P = 0.001), but comparable between patients with abnormal and normal IP. At follow up, there was no significant difference in the incidence of complications like spontaneous bacterial peritonitis, HRS, VB, HE and death between patients with abnormal and normal IP. CONCLUSION IP was increased in 35% of patients with LC; however, it was not associated with a higher incidence of disease-related complications.
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Affiliation(s)
- Jaya Benjamin
- Departments of Gastroenterology and Human Nutrition Microbiology, All India Institute of Medical Sciences, New Delhi, India
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21
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Price ER, Brun A, Fasulo V, Karasov WH, Caviedes-Vidal E. Intestinal perfusion indicates high reliance on paracellular nutrient absorption in an insectivorous bat Tadarida brasiliensis. Comp Biochem Physiol A Mol Integr Physiol 2013; 164:351-5. [DOI: 10.1016/j.cbpa.2012.11.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2012] [Revised: 11/05/2012] [Accepted: 11/05/2012] [Indexed: 10/27/2022]
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Norman K, Pirlich M, Schulzke JD, Smoliner C, Lochs H, Valentini L, Bühner S. Increased intestinal permeability in malnourished patients with liver cirrhosis. Eur J Clin Nutr 2012; 66:1116-9. [PMID: 22872031 DOI: 10.1038/ejcn.2012.104] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND/OBJECTIVE Malnutrition is a prominent feature in liver cirrhosis, with deleterious impact on clinical outcome. The objective of this study is to investigate whether malnutrition is associated with increased gastrointestinal permeability in liver cirrhosis reflected by altered urinary excretion of non-metabolizable sugar probes. SUBJECTS/METHODS Patients with advanced liver cirrhosis (Child Pugh Score B or C) were recruited. Nutritional status was determined according to the Subjective Global Assessment. Intestinal permeability was assessed by measuring the urinary excretion of orally administered, non-metabolized sugar probe molecules. The lactulose/mannitol ratio served as marker for intestinal permeability and reflects non-carrier-mediated transcellular and paracellular transport of the small intestine during the first 5 h. Sucrose recovery in urine within the first 5 h reflects gastroduodenal permeability; sucralose recovery in urine 5-26 h after consumption reflects colonic permeability. RESULTS Sixty-four patients (56.7±10.8 years; 33% female) were included in the study. Twenty-one patients were considered well nourished according to the Subjective Global Assessment, 23 moderately nourished and 20 patients severely malnourished; 74% had alcoholic liver disease and 67% had cirrhosis stage Child C. Gastroduodenal and colonic permeability was significantly increased in patients with liver cirrhosis compared with 63 healthy controls (0.23±0.22 and 1.37±1.42% vs 0.14±0.10 and 0.41±0.72% in controls), but not different between well and malnourished subjects. Small intestinal permeability (lactulose/mannitol ratio) was increased in all patients (0.069±0.055%) and further increased in malnourished patients (0.048±0.031% vs 0.084±0.061%, P=0.004) due to decreased mannitol recovery only. CONCLUSIONS Gastric, small intestinal and even colonic permeability was altogether increased in liver cirrhosis, and malnutrition was associated with further increased small intestinal permeability indicative of villous atrophy.
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Affiliation(s)
- K Norman
- Medizinische Klinik für Gastroenterologie, Infektiologie und Rheumatologie-Einschl. Arbeitsbereich Ernährungsmedizin, Charité Universitätsmedizin Berlin, Campus Charité Mitte, Berlin, Germany.
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Sequeira IR, Lentle RG, Kruger MC, Hurst RD. The effect of aspirin and smoking on urinary excretion profiles of lactulose and mannitol in young women: toward a dynamic, aspirin augmented, test of gut mucosal permeability. Neurogastroenterol Motil 2012; 24:e401-11. [PMID: 22757650 DOI: 10.1111/j.1365-2982.2012.01969.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND We explored the temporal dynamics of the lactulose mannitol test and the influence of a single dose of aspirin. METHODS Twenty healthy female volunteers each received 600 mg aspirin or placebo in random sequence and were subsequently dosed with 10 g lactulose and 5 g mannitol, their urine collected every half hour for 6h. KEY RESULTS The lactulose:mannitol ratios (LMR) of urine samples collected over the entire 6-h period were significantly higher than those collected in the first 3 h. Greater quantities of mannitol were excreted over the first than the subsequent 3 h. A similar pattern of temporal variation in mannitol excretion was found in smokers and non-smokers and was maintained following administration of a single 600 mg dose of aspirin. The rates at which lactulose was excreted were relatively constant over the entire 6 h period of collection, but mean levels were increased over the entire 6 h following the administration of aspirin. The effect of aspirin did not differ significantly between smokers and non-smokers. CONCLUSIONS & INFERENCES While the LMR test is sufficiently sensitive to reproducibly detect the increase in intestinal permeability resulting from a single 600 mg oral dose of aspirin, the temporal patterns of excretion of mannitol and lactulose differ both in the presence and absence of aspirin. Hence, variation in sampling period and in method of dosage are likely to influence the result and it is preferable to examine the patterns of absorption of component sugars separately with due regard to the method of dosage.
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Affiliation(s)
- I R Sequeira
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand
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24
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van Wijck K, Verlinden TJM, van Eijk HMH, Dekker J, Buurman WA, Dejong CHC, Lenaerts K. Novel multi-sugar assay for site-specific gastrointestinal permeability analysis: a randomized controlled crossover trial. Clin Nutr 2012; 32:245-51. [PMID: 22892368 DOI: 10.1016/j.clnu.2012.06.014] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 04/06/2012] [Accepted: 06/26/2012] [Indexed: 01/14/2023]
Abstract
BACKGROUND & AIMS Increased gastrointestinal (GI) permeability is an important hallmark of many conditions, potentially leading to antigen exposure and sepsis. Current permeability tests are hampered by analytical limitations. This study aims to compare the accuracy of our multi-sugar (MS) and the classical dual sugar (DS) test for detection of increased GI permeability. METHODS Ten volunteers received permeability analysis using MS (1 g sucrose, lactulose, sucralose, erythritol, 0.5 g rhamnose in water) or DS (5 g lactulose, 0.5 g rhamnose), after indomethacin or placebo. Blood and urine were analyzed by isocratic LC-MS. RESULTS MS testing revealed significantly elevated urinary lactulose/rhamnose (L/R) ratios after indomethacin, due to enhanced lactulose excretion (P < .01) and unaltered rhamnose excretion. The DS test showed increased L/R ratios, due to increased lactulose excretion and decreased rhamnose excretion (both P < .05). After indomethacin, plasma L/R increased in both assays (P < .05 and P < .01). Urinary and plasma L/R ratios correlated significantly. Indomethacin increased sucrose excretion and 0-1 h sucrose/rhamnose. Colon permeability was unchanged. CONCLUSIONS Sensitive permeability analysis is feasible in plasma and urine using MS or DS test. In contrast to the DS test, monosaccharide excretion is not decreased by the MS test. In short, the MS test provides accurate, site-specific information on gastroduodenal, small, and large intestinal permeability. Registered at US National Library of Medicine (http://www.clinicaltrials.gov, NCT00943345).
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Affiliation(s)
- Kim van Wijck
- Top Institute Food and Nutrition, Wageningen, The Netherlands.
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The capacity for paracellular absorption in the insectivorous bat Tadarida brasiliensis. J Comp Physiol B 2012; 183:289-96. [PMID: 22872186 DOI: 10.1007/s00360-012-0696-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2012] [Revised: 06/26/2012] [Accepted: 07/11/2012] [Indexed: 10/28/2022]
Abstract
Water-soluble nutrients are absorbed by the small intestine via transcellular and paracellular processes. The capacity for paracellular absorption seems greater in fliers than in nonfliers, although that conclusion rests mainly on a comparison of flying birds and nonflying mammals because only two frugivorous bat species have been studied. Furthermore, the bats studied so far were relatively large (>85 g, compared with most bat species which are <20 g) and were not insectivores (like about 70 % of bat species). We studied the small (11 g) insectivorous bat Tadarida brasiliensis and tested the prediction that the capacity for paracellular absorption would be as high as in the other bat and avian species studied so far, well above that in terrestrial, nonflying mammals. Using standard pharmacokinetic technique, we measured the extent of absorption (fractional absorption = f) of inert carbohydrate probes: L-arabinose (MM = 150.13) absorbed exclusively by paracellular route and 3OMD-glucose (MM = 194) absorbed both paracellularly and transcellularly. As predicted, the capacity of paracellular absorption in this insectivorous bat was high (L-arabinose f = 1.03 ± 0.14) as in other frugivorous bats and small birds. Absorption of 3OMD-glucose was also complete (f = 1.09 ± 0.17), but >80 % was accounted for by paracellular absorption. We conclude that passive paracellular absorption of molecules of the size of amino acids and glucose is extensive in this bat and, generally in bats, significantly higher than that in nonflying mammals, although the exact extent can be somewhat lower or higher depending on molecule size, polarity and charge.
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Karasov WH, Caviedes-Vidal E, Bakken BH, Izhaki I, Samuni-Blank M, Arad Z. Capacity for absorption of water-soluble secondary metabolites greater in birds than in rodents. PLoS One 2012; 7:e32417. [PMID: 22389702 PMCID: PMC3289669 DOI: 10.1371/journal.pone.0032417] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Accepted: 01/29/2012] [Indexed: 11/18/2022] Open
Abstract
Plant secondary metabolites (SMs) are pervasive in animal foods and potentially influence feeding behavior, interspecies interactions, and the distribution and abundance of animals. Some of the major classes of naturally occurring SMs in plants include many water-soluble compounds in the molecular size range that could cross the intestinal epithelium via the paracellular space by diffusion or solvent drag. There are differences among species in paracellular permeability. Using Middle Eastern rodent and avian consumers of fruits containing SMs, we tested the hypothesis that avian species would have significantly higher paracellular permeability than rodent species. Permeability in intact animals was assessed using standard pharmacological methodology to measure absorption of two radiolabeled, inert, neutral water-soluble probes that do not interact with intestinal nutrient transporters, L-arabinose (Mr = 150.1 Da) and lactulose (Mr = 342.3 Da). We also measured absorption of labeled 3-O-methyl-D-glucose (3OMD-glucose; Mr = 194.2 Da), which is a nonmetabolized analogue of D-glucose that is passively absorbed through the paracellular space but also transported across the enterocyte membranes. Most glucose was absorbed by all species, but arabinose fractional absorption (f) was nearly three times higher in birds (1.03±0.17, n = 15 in two species) compared to rodents (0.37±0.06, n = 10 in two species) (P<0.001). Surprisingly, the apparent rates of absorption in birds of arabinose exceeded those of 3OMD-glucose. Our findings are in agreement with previous work showing that the paracellular pathway is more prominent in birds relative to nonflying mammals, and suggests that birds may be challenged by greater absorption of water-soluble, dietary SMs. The increased expression of the paracellular pathway in birds hints at a tradeoff: the free energy birds gain by absorbing water-soluble nutrients passively may be offset by the metabolic demands placed on them to eliminate concomitantly absorbed SMs.
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Affiliation(s)
- William H Karasov
- Department of Forest and Wildlife Ecology, Russell Laboratories, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
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Ménard S, Lebreton C, Schumann M, Matysiak-Budnik T, Dugave C, Bouhnik Y, Malamut G, Cellier C, Allez M, Crenn P, Schulzke JD, Cerf-Bensussan N, Heyman M. Paracellular versus transcellular intestinal permeability to gliadin peptides in active celiac disease. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 180:608-15. [PMID: 22119716 DOI: 10.1016/j.ajpath.2011.10.019] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 10/11/2011] [Accepted: 10/25/2011] [Indexed: 12/22/2022]
Abstract
The intestinal permeability of undegraded α9-gliadin peptide 31-49 (p31-49) and 33-mer gliadin peptides is increased in active celiac disease. Two distinct transport pathways have been proposed: paracellular leakage through epithelial tight junctions and protected transcellular transport. To analyze the relative contribution of these pathways, we compared mucosa-to-serosa permeability of small and large permeability markers [ionic conductance (G), mannitol, 182 Da; horseradish peroxidase, 40 kDa] and gliadin peptides [33-mer (p56-88, 3900 Da), 19-mer (p31-49, 2245 Da; and p202-220, 2127 Da), and 12-mer (p57-68, 1453 Da)] in duodenal biopsy specimens mounted in Ussing chambers. The permeability of intact peptides was much higher for p31-49 or 33-mer than for horseradish peroxidase, p202-220, and p57-68. A positive correlation was observed between G, an index of paracellular diffusion of ions, and mannitol permeability. The absence of correlation between G and permeability to intact 33-mer or p31-49 did not favor paracellular diffusion of the peptides. Immunofluorescence studies indicated that 33-mer enters the early endosome antigen 1-positive compartment but escapes the lysosomal-associated protein 2-positive compartment. The results underline that mannitol and ionic conductance G cannot be considered markers of permeability to gliadin peptides. In active celiac disease, increases in transcellular permeability to intact gliadin peptides might be considered in treatment strategies aimed at controlling epithelial permeability to gluten.
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Affiliation(s)
- Sandrine Ménard
- INSERM, Unit 989, Paris, France; The University of Paris, Descartes, Paris, France
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The significance of altered gastrointestinal permeability in cancer patients. Curr Opin Support Palliat Care 2011; 5:47-54. [PMID: 21326003 DOI: 10.1097/spc.0b013e328343a043] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
PURPOSE OF REVIEW The diagnosis and assessment of severity of intestinal mucosal damage in cancer patients treated by anticancer therapy still rely mostly on anamnestic data. We review here studies reporting on the use of intestinal permeability measurements in cancer patients before and during treatment. RECENT FINDINGS The concept of intestinal permeability is based on differential permeability of intestinal mucosa to molecular markers, including monosaccharides and disaccharides, along the crypt-villus axis. Cytotoxic drugs and/or radiation impair replacement of intestinal epithelia and induce flattening of the villi, leading to increased exposure of luminal contents to crypts and increased disaccharide absorption. Increased disaccharide/monosaccharide ratio and decreased xylose absorption have been described in patients treated by radiotherapy as well as different cytotoxic or targeted agents across a spectrum of malignant disorders. Intestinal permeability changes correlated with clinical manifestations, including diarrhea, mucositis, neutropenic enterocolitis and systemic infections. The measurement of intestinal permeability has also been used as a surrogate end-point in interventional studies. SUMMARY Intestinal permeability testing using nonmetabolized sugars may represent a tool for noninvasive objective assessment of intestinal toxicity of anticancer therapy.
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Effect of meloxicam and meloxicam with misoprostol on serum prostaglandins and gastrointestinal permeability in healthy beagle dogs. ACTA VETERINARIA 2011. [DOI: 10.2298/avb1101033r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Dietary calcium decreases but short-chain fructo-oligosaccharides increase colonic permeability in rats. Br J Nutr 2010; 104:1780-6. [PMID: 20691137 DOI: 10.1017/s0007114510002990] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
An increased intestinal permeability is associated with several diseases. Nutrition can influence gut permeability. Previously, we showed that dietary Ca decreases whereas dietary short-chain fructo-oligosaccharides (scFOS) increase intestinal permeability in rats. However, it is unknown how and where in the gastrointestinal tract Ca and scFOS exert their effects. Rats were fed a Western low-Ca control diet, or a similar diet supplemented with either Ca or scFOS. Lactulose plus mannitol and Cr-EDTA were added to the diets to quantify small and total gastrointestinal permeability, respectively. Additionally, colonic tissue was mounted in Ussing chambers and exposed to faecal water of these rats. Dietary Ca immediately decreased urinary Cr-EDTA excretion by 24 % in Ca-fed rats compared with control rats. Dietary scFOS increased total Cr-EDTA permeability gradually with time, likely reflecting relatively slow gut microbiota adaptations, which finally resulted in a 30 % increase. The lactulose:mannitol ratio was 15 % higher for Ca-fed rats and 16 % lower for scFOS-fed rats compared with control rats. However, no dietary effect was present on individual urinary lactulose and mannitol excretion. The faecal waters did not influence colonic permeability in Ussing chambers. In conclusion, despite effects on the lactulose:mannitol ratio, individual lactulose values did not alter, indicating that diet did not influence small-intestinal permeability. Therefore, both nutrients affect permeability only in the colon: Ca decreases, while scFOS increase colonic permeability. As faecal water did not influence permeability in Ussing chambers, probably modulation of mucins and/or microbiota is important for the in vivo effects of dietary Ca and scFOS.
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Multiple facets of intestinal permeability and epithelial handling of dietary antigens. Mucosal Immunol 2010; 3:247-59. [PMID: 20404811 DOI: 10.1038/mi.2010.5] [Citation(s) in RCA: 242] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The intestinal epithelium, the largest interface between the host and environment, regulates fluxes of ions and nutrients and limits host contact with the massive load of luminal antigens. Local protective and tolerogenic immune responses toward luminal content depend on antigen sampling by the gut epithelial layer. Whether, and how exaggerated, the entrance of antigenic macromolecules across the gut epithelium might initiate and/or perpetuate chronic inflammation as well as the respective contribution of paracellular and transcellular permeability remains a matter of debate. To this extent, experimental studies involving the in vivo assessment of intestinal permeability using small inert molecules do not necessarily correlate with the uptake of larger dietary antigens. This review analyzes both the structural and functional aspects of intestinal permeability with special emphasis on antigen handling in healthy and diseased states and consequences on local immune responses to food antigens.
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Casellas F, Torrejón A, Vilaseca J, Aparici A, Casaus M, Rodríguez P, Guarner F. Influence of colectomy on hydrogen excretion in breath. Int J Colorectal Dis 2010; 25:485-9. [PMID: 19902224 DOI: 10.1007/s00384-009-0832-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/14/2009] [Indexed: 02/04/2023]
Abstract
INTRODUCTION Hydrogen breath test is the most commonly used method to analyze carbohydrate absorption and diagnose carbohydrate malabsorption. The result of the H(2) breath test is influenced by different factors, which are mostly related to quantitative or qualitative aspects of colonic flora. A scarcely studied variable is the effect of colonic anatomical integrity on H(2) excretion in breath. PURPOSE The present study aims to determine whether loss of colonic integrity reduces H(2) excretion capacity after an oral load of an unabsorbable carbohydrate. METHODS An observational study was conducted in three patient groups: controls with preserved colon, patients with partial colectomy, and patients with complete colectomy and ileostomy. H(2) concentration in breath was measured by gas chromatography every 10 min for 3 h after oral lactulose administration. RESULTS Twenty-two patients with partial colectomy, 18 controls with preserved colon, and seven patients with ileostomy were included. H(2) excretion after lactulose did not differ between patients with partial colectomy and controls (basal excretion = 8.5 vs 4 ppm; delta increase = 50.0 vs 47.5 ppm; area under the curve = 4,480.0 vs 4,710.5 ppm/min). In contrast, H(2) excretion was significantly lower in the ileostomy group. CONCLUSIONS Partial colectomy does not influence the capacity for H(2) excretion after oral unabsorbable carbohydrate administration.
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Affiliation(s)
- Francesc Casellas
- Digestive System Research Unit, Hospital Universitari Vall d'Hebron, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Barcelona 08035, Spain.
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McWhorter TJ, Caviedes-Vidal E, Karasov WH. The integration of digestion and osmoregulation in the avian gut. Biol Rev Camb Philos Soc 2009; 84:533-65. [DOI: 10.1111/j.1469-185x.2009.00086.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Valentini L, Eggers J, Ockenga J, Haas VK, Bühner S, Winklhofer-Roob BM, Hengstermann S, Sinn B, Weigel A, Norman K, Pirlich M, Lochs H. Association between intestinal tight junction permeability and whole-body electrical resistance in healthy individuals: A hypothesis. Nutrition 2009; 25:706-14. [DOI: 10.1016/j.nut.2008.11.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Revised: 11/26/2008] [Accepted: 11/30/2008] [Indexed: 01/05/2023]
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Abstract
Exocrine pancreatic insufficiency caused by chronic pancreatitis results from various factors which regulate digestion and absorption of nutrients. Pancreatic function has been extensively studied over the last 40 years, even if some aspects of secretion and gastrointestinal adaptation are not completely understood. The main clinical manifestations of exocrine pancreatic insufficiency are fat malabsorption, known as steatorrhea, which consists of fecal excretion of more than 6 g of fat per day, weight loss, abdominal discomfort and abdominal swelling sensation. Fat malabsorption also results in a deficit of fat-soluble vitamins (A, D, E and K) with consequent clinical manifestations. The relationships between pancreatic maldigestion, intestinal ecology and intestinal inflammation have not received particular attention, even if in clinical practice these mechanisms may be responsible for the low efficacy of pancreatic extracts in abolishing steatorrhea in some patients. The best treatments for pancreatic maldigestion should be re-evaluated, taking into account not only the correction of pancreatic insufficiency using pancreatic extracts and the best duodenal pH to permit optimal efficacy of these extracts, but we also need to consider other therapeutic approaches including the decontamination of intestinal lumen, supplementation of bile acids and, probably, the use of probiotics which may attenuate intestinal inflammation in chronic pancreatitis patients.
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Ungell AL. In Vitro Absorption Studies and Their Relevance to Absorption from the GI Tract. Drug Dev Ind Pharm 2008. [DOI: 10.3109/03639049709148694] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Bouritius H, van Hoorn DC, Oosting A, van Middelaar-Voskuilen MC, van Limpt CJP, Lamb KJ, van Leeuwen PAM, Vriesema AJM, van Norren K. Carbohydrate supplementation before operation retains intestinal barrier function and lowers bacterial translocation in a rat model of major abdominal surgery. JPEN J Parenter Enteral Nutr 2008; 32:247-53. [PMID: 18443136 DOI: 10.1177/0148607108316191] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND Overnight fasting of rats augments the susceptibility of the small intestine to ischemia-reperfusion damage. Feeding before surgery may improve injuries to distant organs that were induced by ischemia-reperfusion. The present study tested the hypothesis that one of the food constituents, namely carbohydrates, may be responsible for the protective effect of preoperative feeding on postoperative organ dysfunction. METHODS Male Wistar rats were fed ad libitum for 5 d and had either free access to water or free access to a carbohydrate drink and water. Then they were fasted for 16 h and access remained to either water or a carbohydrate drink and water. Following this, the arteria mesenterica superior was clamped for 60 min followed by 180 min of reperfusion. Subsequently, the intestinal permeability of stripped ileum was determined by measuring the mucosal to serosal flux in Ussing chambers. For assessment of bacterial content, organs were aseptically removed and assessed for bacterial content by culture under anaerobic conditions. RESULTS Preoperative supplementation with carbohydrates resulted in a better maintenance of intestinal barrier function when compared with water supplemented animals. Moreover, carbohydrate supplementation resulted in a reduction in the ischemiareperfusion-induced increase in bacterial content of the liver, kidney, and mesenteric lymph nodes. CONCLUSIONS Preoperative intake of carbohydrates by rats retains both the intestinal barrier function and prevents translocation of bacteria to distant organs.
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McWhorter TJ, Karasov WH. Paracellular nutrient absorption in a gum-feeding new world primate, the common marmoset Callithrix jacchus. Am J Primatol 2008; 69:1399-411. [PMID: 17487879 DOI: 10.1002/ajp.20443] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The common marmoset is one of the few callitrichid species that is not threatened or endangered in the wild, and is widely used in biomedical research, yet relatively little is understood about its digestive physiology. Dietary specialization on plant exudates has lead to relatively reduced small intestines, yet the common marmoset has exceptional dietary breadth, allowing it to successfully utilize a variety of habitats. We predicted that passive, paracellular nutrient absorption would be used by the common marmoset to a greater extent than in other non-flying mammals. We measured the bioavailability and rates of absorption of two metabolically inert carbohydrates not transported by mediated pathways (L-rhamnose and cellobiose, molecular masses of 164 and 342, respectively) to measure paracellular uptake, and of a non-metabolized D-glucose analog (3-O-methyl-D-glucose) to measure total uptake by both mediated and paracellular pathways. We found high bioavailability of 3-O-methyl-D-glucose (83+/-5%), and much higher bioavailability of the paracellular probes than in similarly sized non-flying mammals (30+/-3% and 19+/-2% for L-rhamnose and cellobiose, respectively). Passive, paracellular nutrient absorption accounts for around 30% of total glucose absorption in common marmosets and intestinal permeability is significantly higher than in humans, the only other species of primate measured to date. This may allow the common marmoset to maintain high digestive efficiency when feeding on higher quality foods (fruit, arthropods, gums with higher proportions of simple sugars), in spite of relatively reduced small intestines correlated with adaptations for fermentative digestion of plant gums. We find no evidence to support, in primates, the hypothesis that reliance on paracellular nutrient absorption should increase with body size in mammals, but suggest instead that it may be associated with small body size and/or taxon-specific adaptations to diet.
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Affiliation(s)
- Todd J McWhorter
- Department of Wildlife Ecology, 226 Russell Labs, University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI, USA.
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Caviedes-Vidal E, Karasov WH, Chediack JG, Fasulo V, Cruz-Neto AP, Otani L. Paracellular absorption: a bat breaks the mammal paradigm. PLoS One 2008; 3:e1425. [PMID: 18183305 PMCID: PMC2173942 DOI: 10.1371/journal.pone.0001425] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Accepted: 07/31/2007] [Indexed: 11/20/2022] Open
Abstract
Bats tend to have less intestinal tissue than comparably sized nonflying mammals. The corresponding reduction in intestinal volume and hence mass of digesta carried is advantageous because the costs of flight increase with load carried and because take-off and maneuverability are diminished at heavier masses. Water soluble compounds, such as glucose and amino acids, are absorbed in the small intestine mainly via two pathways, the transporter-mediated transcellular and the passive, paracellular pathways. Using the microchiropteran bat Artibeus literatus (mean mass 80.6±3.7 g), we tested the predictions that absorption of water-soluble compounds that are not actively transported would be extensive as a compensatory mechanism for relatively less intestinal tissue, and would decline with increasing molecular mass in accord with sieve-like paracellular absorption. Using a standard pharmacokinetic technique, we fed, or injected intraperitonealy the metabolically inert carbohydrates L-rhamnose (molecular mass = 164 Da) and cellobiose (molecular mass = 342 Da) which are absorbed only by paracellular transport, and 3-O-methyl-D-glucose (3OMD-glucose) which is absorbed via both mediated (active) and paracellular transport. As predicted, the bioavailability of paracellular probes declined with increasing molecular mass (rhamnose, 90±11%; cellobiose, 10±3%, n = 8) and was significantly higher in bats than has been reported for laboratory rats and other mammals. In addition, absorption of 3OMD-glucose was high (96±11%). We estimated that the bats rely on passive, paracellular absorption for more than 70% of their total glucose absorption, much more than in non-flying mammals. Although possibly compensating for less intestinal tissue, a high intestinal permeability that permits passive absorption might be less selective than a carrier-mediated system for nutrient absorption and might permit toxins to be absorbed from plant and animal material in the intestinal lumen.
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Affiliation(s)
- Enrique Caviedes-Vidal
- Laboratorio de Biología Prof. E. Caviedes Codelia, Facultad de Ciencias Humanas, Universidad Nacional de San Luis-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Luis, Argentina.
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Caviedes-Vidal E, McWhorter TJ, Lavin SR, Chediack JG, Tracy CR, Karasov WH. The digestive adaptation of flying vertebrates: high intestinal paracellular absorption compensates for smaller guts. Proc Natl Acad Sci U S A 2007; 104:19132-7. [PMID: 18025481 PMCID: PMC2141920 DOI: 10.1073/pnas.0703159104] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Indexed: 11/18/2022] Open
Abstract
Anecdotal evidence suggests that birds have smaller intestines than mammals. In the present analysis, we show that small birds and bats have significantly shorter small intestines and less small intestine nominal (smooth bore tube) surface area than similarly sized nonflying mammals. The corresponding >50% reduction in intestinal volume and hence mass of digesta carried is advantageous because the energetic costs of flight increase with load carried. But, a central dilemma is how birds and bats satisfy relatively high energy needs with less absorptive surface area. Here, we further show that an enhanced paracellular pathway for intestinal absorption of water-soluble nutrients such as glucose and amino acids may compensate for reduced small intestines in volant vertebrates. The evidence is that l-rhamnose and other similarly sized, metabolically inert, nonactively transported monosaccharides are absorbed significantly more in small birds and bats than in nonflying mammals. To broaden our comparison and test the veracity of our finding we surveyed the literature for other similar studies of paracellular absorption. The patterns found in our focal species held up when we included other species surveyed in our analysis. Significantly greater amplification of digestive surface area by villi in small birds, also uncovered by our analysis, may provide one mechanistic explanation for the observation of higher paracellular absorption relative to nonflying mammals. It appears that reduced intestinal size and relatively enhanced intestinal paracellular absorption can be added to the suite of adaptations that have evolved in actively flying vertebrates.
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Affiliation(s)
- Enrique Caviedes-Vidal
- *Laboratorio de Biología “Prof. E. Caviedes Codelia,” Facultad de Ciencias Humanas, and Departamento de Bioquímica y Ciencias Biológicas, Universidad Nacional de San Luís–Consejo Nacional de Investigaciones Científicas y Técnicas, 5700 San Luis, Argentina
| | - Todd J. McWhorter
- Department of Forest and Wildlife Ecology, University of Wisconsin, Madison, WI 53717
- School of Veterinary and Biomedical Sciences, Murdoch University, Murdoch 6150, Australia
| | - Shana R. Lavin
- Department of Forest and Wildlife Ecology, University of Wisconsin, Madison, WI 53717
| | - Juan G. Chediack
- *Laboratorio de Biología “Prof. E. Caviedes Codelia,” Facultad de Ciencias Humanas, and Departamento de Bioquímica y Ciencias Biológicas, Universidad Nacional de San Luís–Consejo Nacional de Investigaciones Científicas y Técnicas, 5700 San Luis, Argentina
| | - Christopher R. Tracy
- Department of Forest and Wildlife Ecology, University of Wisconsin, Madison, WI 53717
- Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 84990, Israel; and
- School of Science and Primary Industries, Charles Darwin University, Darwin 0909, Australia
| | - William H. Karasov
- Department of Forest and Wildlife Ecology, University of Wisconsin, Madison, WI 53717
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Lavin SR, McWhorter TJ, Karasov WH. Mechanistic bases for differences in passive absorption. J Exp Biol 2007; 210:2754-64. [PMID: 17644690 DOI: 10.1242/jeb.006114] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
SUMMARY
Increasing evidence indicates that small birds have more extensive non-mediated, paracellular intestinal absorption of hydrosoluble compounds than do mammals, although studies have not employed uniform methodologies or demonstrated differences at the tissue level. The mechanistic bases behind apparent species differences are poorly understood. We show using uniform methodology at the whole-animal level that intact, unanesthetized pigeons had significantly higher absorption of l-arabinose and l-rhamnose, two water-soluble compounds used to measure paracellular absorption, than similarly sized laboratory rats. The species differences were also evident using perfused isolated loops of duodenum,showing that the difference in paracellular absorption occurred at the tissue level, even when d-glucose absorption rates(transcellular+paracellular) were similar between the two species. The greater absorption of these probes in pigeons could not be explained by mediated uptake of the putative paracellular probes, or by increased nominal surface area, increased villus area or increased number of tight junctions. Rats and pigeons had comparable absorption of larger probes, which is consistent with similar effective pore size of the tight junction between enterocytes. The elimination of these mechanistic explanations might suggest that pigeon intestine has relatively higher paracellular solvent drag, but pigeon duodenal segments did not have higher net water absorption than rat duodenal segments. Whatever the exact mechanism(s), the paracellular pathway of both species limits substantial (>5%) fractional absorption to molecules smaller than about 4.8 Å (Mr ca. 350), and permeability to smaller molecules at the tissue level is higher in pigeons than in rats.
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Affiliation(s)
- Shana R Lavin
- Department of Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA
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van Minnen LP, Blom M, Timmerman HM, Visser MR, Gooszen HG, Akkermans LMA. The use of animal models to study bacterial translocation during acute pancreatitis. J Gastrointest Surg 2007; 11:682-9. [PMID: 17468930 PMCID: PMC1915599 DOI: 10.1007/s11605-007-0088-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Accepted: 11/29/2006] [Indexed: 01/31/2023]
Abstract
Infection of pancreatic necrosis with intestinal flora is accepted to be a main predictor of outcome during severe acute pancreatitis. Bacterial translocation is the process whereby luminal bacteria migrate to extraintestinal sites. Animal models were proven indispensable in detecting three major aspects of bacterial translocation: small bowel bacterial overgrowth, mucosal barrier failure, and disturbed immune responses. Despite the progress made in the knowledge of bacterial translocation, the exact mechanism, origin and route of bacteria, and the optimal prophylactic and treatment strategies remain unclear. Methodological restrictions of animal models are likely to be the cause of this uncertainty. A literature review of animal models used to study bacterial translocation during acute pancreatitis demonstrates that many experimental techniques per se interfere with intestinal flora, mucosal barrier function, or immune response. Interference with these major aspects of bacterial translocation complicates interpretation of study results. This paper addresses these and other issues of animal models most frequently used to study bacterial translocation during acute pancreatitis.
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Affiliation(s)
- L. P. van Minnen
- Department of Surgery, Gastrointestinal Research Unit, University Medical Center Utrecht, P.O. Box 85500, Utrecht, 3508 GA The Netherlands
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - M. Blom
- Department of Surgery, Gastrointestinal Research Unit, University Medical Center Utrecht, P.O. Box 85500, Utrecht, 3508 GA The Netherlands
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - H. M. Timmerman
- Department of Surgery, Gastrointestinal Research Unit, University Medical Center Utrecht, P.O. Box 85500, Utrecht, 3508 GA The Netherlands
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - M. R. Visser
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - H. G. Gooszen
- Department of Surgery, Gastrointestinal Research Unit, University Medical Center Utrecht, P.O. Box 85500, Utrecht, 3508 GA The Netherlands
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - L. M. A. Akkermans
- Department of Surgery, Gastrointestinal Research Unit, University Medical Center Utrecht, P.O. Box 85500, Utrecht, 3508 GA The Netherlands
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
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Balzan S, de Almeida Quadros C, de Cleva R, Zilberstein B, Cecconello I. Bacterial translocation: overview of mechanisms and clinical impact. J Gastroenterol Hepatol 2007; 22:464-71. [PMID: 17376034 DOI: 10.1111/j.1440-1746.2007.04933.x] [Citation(s) in RCA: 250] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Bacterial translocation (BT) is a phenomenon in which live bacteria or its products cross the intestinal barrier. Gut translocation of bacteria has been shown in both animal and human studies. BT and its complications have been shown clearly to occur in animal models, but its existence and importance in humans has been difficult to ascertain. We review the mechanisms of BT and its clinical impact based on the current literature.
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Affiliation(s)
- Silvio Balzan
- Postgraduate Program, Gastroenterology Department, Digestive Surgery Division, University of Sao Paulo Medical School, Sao Paulo, Brazil.
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Choi K, Lee SS, Oh SJ, Lim SY, Lim SY, Jeon WK, Oh TY, Kim JW. The effect of oral glutamine on 5-fluorouracil/leucovorin-induced mucositis/stomatitis assessed by intestinal permeability test. Clin Nutr 2007; 26:57-62. [PMID: 16949180 DOI: 10.1016/j.clnu.2006.07.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2006] [Revised: 05/23/2006] [Accepted: 07/04/2006] [Indexed: 10/24/2022]
Abstract
BACKGROUND & AIMS Systemic chemotherapy may damage gastrointestinal epithelium. Mucositis is associated with increased intestinal permeability (IP). It is known that IP test with chromium 51-ethylene diaminetetra-acetate (51Cr-EDTA) is a useful tool to assess the mucositis. Oral glutamine supplements (OGS) may have a role in the prevention of chemotherapy-induced mucositis/stomatitis. The aim of this study was to characterize the relationship between the urinary excretion of 51Cr-EDTA and the severity of mucositis, and the effect of OGS on 5-fluorouracil/leucovorin (FU/LV)-induced mucositis/stomatitis. METHODS Fifty-one patients with advanced or metastatic cancer received FU/LV chemotherapy. The control group included 18 healthy volunteers. IP was assessed via the measurement of 51Cr-EDTA urinary excretion after oral challenge, on days 7 after the discontinuation of chemotherapy. Of the 51 patients, 22 patients received OGS (30 g/day) and 29 received only best supportive care (BSC). Glutamine supplementation continued for 15 days. It was initiated at least 3 days before the beginning of chemotherapy. Mucositis/stomatitis was graded according to version 3.0 of the Common Terminology Criteria for Adverse Events. RESULTS In the chemotherapy group, the median (25 percentile, 75 percentile) IP test score was significantly higher than those of the control group [6.78% (4.63, 10.66) vs. 2.17% (1.38, 2.40), P<0.001]. The severity of stomatitis was significantly correlated with IP test scores (r=0.898, P<0.001). In the OGS group, the median IP test score was significantly lower than that of the BSC group [4.69% (3.10, 6.48) vs. 8.54% (6.48, 15.31), P<0.001]. A mucositis/stomatitis of grade 2-4 was observed in two patients of the OGS group (9%), and in 11 patients (38%) in the BSC group (P<0.001). CONCLUSIONS The IP test may be a useful tool in the evaluation of mucositis/stomatitis. OGS may exert a protective effect on FU/LV-induced mucositis/stomatitis. Further studies, however, will be necessary to define the role of glutamine supplementation in FU/LV-induced mucositis/stomatitis.
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Affiliation(s)
- Kwon Choi
- Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul 110-746, Republic of Korea
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Yen TE, Agatonovic-Kustrin S, Evans AM, Nation RL, Ryand J. Prediction of drug absorption based on immobilized artificial membrane (IAM) chromatography separation and calculated molecular descriptors. J Pharm Biomed Anal 2006; 38:472-8. [PMID: 15890485 DOI: 10.1016/j.jpba.2005.01.040] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2005] [Indexed: 11/29/2022]
Abstract
The aim of this study was to evaluate the usefulness of IAM chromatography in building a model that would allow prediction of drug absorption in humans. The human intestinal absorption values (%HIA) for 52 drugs with low to high intestinal absorption were collected from the literature. The retention (capacity factor, k') of each drug was measured by reverse-phase HPLC using an IAM.PC.DD2 column (prepared with phosphatidylcholine analogs, 12 microM, 300A, 15 cm x 4.6 mm) with an eluent of acetonitrile-0.1M phosphate buffer at pH 5.4. In addition, 76 molecular descriptors and solubility parameters for each drug were calculated using ChemSW from the 3D-molecular structures. Stepwise regression was employed to develop a regression equation that would correlate %HIA with molecular descriptors and k'. Human intestinal absorption was reciprocally correlated to the negative value of the capacity factor (-1/k') (R=0.64). The correlation was further improved with the addition of molecular descriptors representing molecular size and shape (molecular width, length and depth) solubility (solubility parameter, HLB, hydrophilic surface area) and polarity (dipole, polar surface area) (R=0.83). Experimentally measured IAM chromatography retention values and calculated molecular descriptors and solubility parameters can be used to predict intestinal absorption of drugs in humans. Developed QSAR can be used as a screening method in the designing of drugs with appropriate IA and for the selection of drug candidates in the early stage of drug discovery process.
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Affiliation(s)
- T E Yen
- Centre for Pharmaceutical Research, University of South Australia, Adelaide, SA, Australia
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Abstract
Patients with cirrhosis are at increased risk of developing infections due to bacterial translocation. This process depends on three principal factors: bacterial overgrowth, immunodepression, and altered intestinal permeability. Intestinal barrier functions may be disturbed in cirrhosis, related to the toxic effects of alcohol (on mucosa and biological membranes) and portal hypertensive enteropathy. Few studies on the assessment of intestinal permeability in cirrhotic patients are available, and contradictory results may be explained by methodological differences. However, four studies using a differential sugar absorption test (lactulose-mannitol test, a combination of an oligosaccharide and a monosaccharide) showed an increased intestinal permeability in cirrhotic patients. The recurrence of spontaneous bacterial peritonitis can be appreciated only by one similar case history, a low rate of protides in ascites (<10 g/L), bilirubinemia > 55 micromol/L, and thrombocytopenia<98.000/mm3. These results suggest that primary antibiotherapy prophylaxis should be recommended, but this recommendation is limited by the risk of bacterial resistant selection and by the fact that no patient survival benefits was shown. Intestinal permeability could be another predictive factor to justify preventive antibiotherapy; but more studies are needed and methods should be standardized (technique used to measure permeability, patient groups involved).
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Affiliation(s)
- David Ancel
- Service d'Hépato-Gastroentérologie, CHU Brabois, 54500 Vandoeuvre-lès-Nancy
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47
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Abstract
Intestinal permeability tests used in the diagnosis of allergic diseases in response to oral food challenge have led to the conclusion that constitutive defects of the intestinal barrier are not the primary cause of allergic diseases. However, perturbation of environmental factors (infection, stress), by increasing intestinal permeability and enhancing danger signals, may favour food allergy in susceptible individuals. The mechanisms of enhanced permeability to specific and bystander antigens have been delineated as well as the molecular events involved in the sequential phases of allergic reactions. Intestinal absorption of food antigens and immune responses are mutually dependent, and luminal (environmental) and serosal (intrinsic) factors synergize to maintain a self-perpetuating cycle in which antigens penetrate the mucosa and induce allergic inflammation.
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Affiliation(s)
- Martine Heyman
- Faculté de Médecine Necker-Enfants Malades, Paris, France.
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Chediack JG, Caviedes-Vidal E, Karasov WH. Electroaffinity in paracellular absorption of hydrophilic d-dipeptides by sparrow intestine. J Comp Physiol B 2005; 176:303-9. [PMID: 16317547 DOI: 10.1007/s00360-005-0052-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Revised: 10/08/2005] [Accepted: 11/01/2005] [Indexed: 11/30/2022]
Abstract
We previously demonstrated size selectivity in the absorption of nonelectrolyte hydrosoluble probes in birds, presumably by the paracellular pathway. Our goal in this study was to determine the charge selectivity in the absorption of hydrosoluble D-dipeptides, because there have been no studies of the electroaffinity of this absorption pathway in birds. For this purpose isosmotic solutions with two hydrophilic D-dipeptides: serine-lysine (positive at pH 7.4) and serine-aspartic (negative at pH 7.4) were gavaged into the stomach in nonanesthetized house sparrows (Passer domesticus), and injected into the pectoralis with a syringe in different trials. Fractional absorption was calculated as F = [AUC by gavage)]/[AUC by injection] (AUC = area under the curve of plasma probe concentration vs. time). Fractional absorption was significantly higher for the positively charged than negatively charged dipeptide (respectively, F=0.30+/-0.05 vs. F=0.17+/-0.03). These findings give the first evidence of cation selectivity by the paracellular route in the absorption of hydrosoluble solutes in the small intestine in birds.
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Affiliation(s)
- Juan G Chediack
- Facultad de Ciencias Humanas, Laboratorio de Biología, Universidad Nacional de San Luis, Casilla de Correos 226, 5700, San Luis, Argentina
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Hull MA, Faluyi OO, Ko CWS, Holwell S, Scott DJ, Cuthbert RJ, Poulsom R, Goodlad R, Bonifer C, Markham AF, Coletta PL. Regulation of stromal cell cyclooxygenase-2 in the Apc Min/+ mouse model of intestinal tumorigenesis. Carcinogenesis 2005; 27:382-91. [PMID: 16219637 DOI: 10.1093/carcin/bgi236] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Cyclooxygenase-2 (Cox-2) is expressed predominantly by stromal cells in intestinal adenomas from the Apc(Min/+) mouse model of familial adenomatous polyposis. We investigated the mechanistic basis of stromal cell Cox-2 expression in Apc(Min/+) mouse adenomas, as well as Cox-2 expression and activity in histologically normal (HN) Apc(Min/+) mouse intestine, in order to gain further insights into regulation of Cox-2 as a potential chemoprevention target. Upregulation of Cox-2 in intestinal tumours is not an intrinsic feature of Apc(Min/+) macrophages as bone marrow-derived Apc(Min/+) macrophages did not exhibit an abnormality in Cox-2 expression or activity. Intestinal permeability to lactulose or mannitol was similar in Apc(Min/+) mice and wild-type littermates, implying that macrophage activation by luminal antigen is unlikely to explain stromal cell Cox-2 induction. Moreover, stromal cells exhibited differential expression of Cox-2 and inducible nitric oxide synthase, suggesting 'alternative' (M2) rather than 'classical' (M1) macrophage activation. Flow cytometric sorting of isolated stromal mononuclear cells (SMNCs), on the basis of M-lysozyme and specific macrophage marker expression, demonstrated that macrophages, neutrophils and non-myelomonocytic cells all contributed to lamina propria prostaglandin (PG) E(2) synthesis. However, the majority of PGE(2) synthesis by macrophages was via a Cox-2-dependent pathway compared with predominant Cox-1-derived PGE(2) production by non-myelomonocytic cells. SMNCs from HN Apc(Min/+) intestinal mucosa exhibited similar levels of Cox-2 mRNA and protein, but produced more Cox-2-derived PGE(2) than wild-type cells at 70 days of age. There was an age-dependent decline in PGE(2) synthesis by Apc(Min/+) SMNCs, despite tumour progression. These data suggest that other Cox-2-independent factors also control PGE(2) levels during Apc(Min/+) mouse intestinal tumorigenesis. Regulation of macrophage Cox-2 expression and other steps in PGE(2) synthesis (e.g. PGE synthase) are valid targets for novel chemoprevention strategies that could minimize or avoid systemic COX-2 inhibition.
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Affiliation(s)
- M A Hull
- Molecular Medicine Unit, University of Leeds, Leeds LS9 7TF, UK.
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Wallon C, Braaf Y, Wolving M, Olaison G, Söderholm JD. Endoscopic biopsies in Ussing chambers evaluated for studies of macromolecular permeability in the human colon. Scand J Gastroenterol 2005; 40:586-95. [PMID: 16036512 DOI: 10.1080/00365520510012235] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Studies of mucosal permeability to protein antigens in humans are limited to in vitro techniques. The use of surgical specimens for such studies has major shortcomings. Endoscopic biopsies in Ussing chambers have been introduced as a means of studying secretion and transepithelial permeability, but have not been evaluated for studies of protein antigen uptake in human intestine. MATERIAL AND METHODS Standard forceps biopsies from the sigmoid colon of 24 healthy volunteers were mounted in Ussing chambers with an exposed tissue area of 1.76 mm2. 51Cr-EDTA (paracellular probe) and horseradish peroxidase (HRP; 45 kDa protein antigen) were used as permeability markers. Mucosal permeability, electrophysiology, histology and energy contents of the biopsies were studied over time. To evaluate the ability of the technique to detect permeability changes, the mucosa was modulated with capric acid, a medium-chain fatty acid, known to affect tight junctions. RESULTS In the Ussing chamber the mucosal biopsies were viable for 160 min with stable levels of ATP and lactate, and only minor changes in morphology. Steady-state permeability with low variability was seen for both markers during the 30-90 min period. Exposure to capric acid induced a rapid decrease in short-circuit current (Isc) and a slower reversible decrease in transepithelial resistance (TER), as well as an increased permeability to 51Cr-EDTA and HRP. CONCLUSIONS Endoscopic biopsies of human colon are viable in Ussing chambers and are reliable tools for studies of mucosal permeability to protein antigens. The technique offers a broad potential for studies of mucosal function in the pathophysiology of human gastrointestinal diseases.
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Affiliation(s)
- Conny Wallon
- Clinical Research Centre, University of Linköping, Sweden.
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