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Foerster RH, Lamprecht G, Rischmüller K, Berlin P, Rousing AQ, Sørensen MV, Leipziger J, Berg P. Urinary acid-base excretion deciphers high acid load from colonic bicarbonate loss in intestinal failure patients with ileocolonic anastomosis - Guidance for composition of parenteral support. Clin Nutr 2024; 43:1043-1050. [PMID: 38554476 DOI: 10.1016/j.clnu.2024.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/03/2024] [Accepted: 03/12/2024] [Indexed: 04/01/2024]
Abstract
BACKGROUND & AIMS Acid-base disturbances are common in short bowel (SB) patients due to increased intestinal bicarbonate loss. However, the resulting systemic acid load has not been quantified. Base excess is used to monitor metabolic acid-base disturbances but inadequately reflects the acid load. Our aim was to investigate the systemic acid/base load in SB-patients to obtain quantitative estimates to guide the composition of parenteral support. METHODS We calculated total acid load in SB patients by summing 24-h urinary net acid excretion (NAE) and the provision of base equivalents in parenteral support. We then compared differences among anatomical SB-types: jejunostomy (SB-J), jejunocolostomy (SB-JC), and jejunoileostomy (SB-JIC). 47 urine samples from 34 SB patients were analyzed for bicarbonate (HCO3-), ammonium (NH4+), and titratable acid (TA) concentrations. NAE was calculated as (TA + NH4+) - HCO3-. Mixed-effects repeated-measures models were used to statistically examine differences between SB-types and associations with parenteral nutrition and NAE. A healthy cohort served as control. RESULTS In comparison to SB-J, SB-JC patients had a 4.1 mmoL/l lower base excess (95% CI: -6.3 to -1.8) and an 84.5 mmol/day higher total acid load (CI: 41.3 to 127.7). There were no significant differences between SB-JIC and SB-J regarding base excess, NAE, or total acid load. Higher amounts of infused acetate, sodium, and chloride, but not the acetate/chloride ratio, were associated with lower NAE and higher base excess. CONCLUSIONS Due to increased colonic bicarbonate loss, patients with SB-JC have a ∼4.4-fold higher acid load than healthy controls. The ion transport mechanisms mediating this bicarbonate loss from the remaining colon need further experimental investigation. NAE could be a useful tool to adjust base infusion in SB.
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Affiliation(s)
- Robert H Foerster
- Rostock University Medical Center, Department of Medicine II, Division of Gastroenterology and Endocrinology, Rostock, Germany
| | - Georg Lamprecht
- Rostock University Medical Center, Department of Medicine II, Division of Gastroenterology and Endocrinology, Rostock, Germany.
| | - Karen Rischmüller
- Rostock University Medical Center, Department of Medicine II, Division of Gastroenterology and Endocrinology, Rostock, Germany
| | - Peggy Berlin
- Rostock University Medical Center, Department of Medicine II, Division of Gastroenterology and Endocrinology, Rostock, Germany
| | - Amalie Q Rousing
- Department of Biomedicine, Health, Aarhus University, Aarhus, Denmark
| | - Mads V Sørensen
- Department of Biomedicine, Health, Aarhus University, Aarhus, Denmark
| | - Jens Leipziger
- Department of Biomedicine, Health, Aarhus University, Aarhus, Denmark
| | - Peder Berg
- Department of Biomedicine, Health, Aarhus University, Aarhus, Denmark
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Billipp TE, Fung C, Webeck LM, Sargent DB, Gologorsky MB, McDaniel MM, Kasal DN, McGinty JW, Barrow KA, Rich LM, Barilli A, Sabat M, Debley JS, Myers R, Howitt MR, von Moltke J. Tuft cell-derived acetylcholine regulates epithelial fluid secretion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.17.533208. [PMID: 36993541 PMCID: PMC10055254 DOI: 10.1101/2023.03.17.533208] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
Tuft cells are solitary chemosensory epithelial cells that can sense lumenal stimuli at mucosal barriers and secrete effector molecules to regulate the physiology and immune state of their surrounding tissue. In the small intestine, tuft cells detect parasitic worms (helminths) and microbe-derived succinate, and signal to immune cells to trigger a Type 2 immune response that leads to extensive epithelial remodeling spanning several days. Acetylcholine (ACh) from airway tuft cells has been shown to stimulate acute changes in breathing and mucocilliary clearance, but its function in the intestine is unknown. Here we show that tuft cell chemosensing in the intestine leads to release of ACh, but that this does not contribute to immune cell activation or associated tissue remodeling. Instead, tuft cell-derived ACh triggers immediate fluid secretion from neighboring epithelial cells into the intestinal lumen. This tuft cell-regulated fluid secretion is amplified during Type 2 inflammation, and helminth clearance is delayed in mice lacking tuft cell ACh. The coupling of the chemosensory function of tuft cells with fluid secretion creates an epithelium-intrinsic response unit that effects a physiological change within seconds of activation. This response mechanism is shared by tuft cells across tissues, and serves to regulate the epithelial secretion that is both a hallmark of Type 2 immunity and an essential component of homeostatic maintenance at mucosal barriers.
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Affiliation(s)
- Tyler E. Billipp
- Department of Immunology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Connie Fung
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Lily M. Webeck
- Department of Immunology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Derek B. Sargent
- Department of Immunology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Matthew B. Gologorsky
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Margaret M. McDaniel
- Department of Immunology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Darshan N. Kasal
- Department of Immunology, University of Washington School of Medicine, Seattle, Washington, USA
| | - John W. McGinty
- Department of Immunology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Kaitlyn A. Barrow
- Center for Immunity and Immunotherapies, Seattle Children’s Research Institute, Seattle, Washington, USA
| | - Lucille M. Rich
- Center for Immunity and Immunotherapies, Seattle Children’s Research Institute, Seattle, Washington, USA
| | | | - Mark Sabat
- Takeda Pharmaceuticals, San Diego, California, USA
| | - Jason S. Debley
- Center for Immunity and Immunotherapies, Seattle Children’s Research Institute, Seattle, Washington, USA
- Department of Pediatrics, Division of Pulmonary and Sleep Medicine, Seattle Children’s Hospital, University of Washington, Seattle, WA, USA
| | | | - Michael R. Howitt
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jakob von Moltke
- Department of Immunology, University of Washington School of Medicine, Seattle, Washington, USA
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3
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Wang L, Yang X, Zhou S, Lyu T, Shi L, Dong Y, Zhang H. Comparative transcriptome analysis revealed omnivorous adaptation of the small intestine of Melinae. Sci Rep 2021; 11:19162. [PMID: 34580368 PMCID: PMC8476558 DOI: 10.1038/s41598-021-98561-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 09/09/2021] [Indexed: 01/04/2023] Open
Abstract
As the main digestive organ, the small intestine plays a vital role in the digestion of animals. At present, most of the research on animal feeding habits focuses on carnivores and herbivores. However, the mechanism of feeding and digestion in omnivores remains unclear. This study aims to reveal the molecular basis of the omnivorous adaptive evolution of Melinae by comparing the transcriptome of the small intestines of Asian Badgers (Meles leucurus) and Northern Hog Badgers (Arctonyx albogularis). We obtained high-quality small intestinal transcriptome data from these two species. Key genes and signalling pathways were analysed through Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and other databases. Research has mainly found that orthologous genes related to six enzymes have undergone adaptive evolution. In addition, the study also found three digestion-related pathways (cGMP-PKG, cAMP, and Hippo). They are related to the digestion and absorption of nutrients, the secretion of intestinal fluids, and the transport of food through the small intestine, which may help omnivorous animals adapt to an omnivorous diet. Our study provides insight into the adaptation of Melinae to omnivores and affords a valuable transcriptome resource for future research.
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Affiliation(s)
| | | | | | | | - Lupeng Shi
- Qufu Normal University, Qufu, 273165, China
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4
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Sollanek KJ, Kenefick RW, Cheuvront SN. Osmolality of Commercially Available Oral Rehydration Solutions: Impact of Brand, Storage Time, and Temperature. Nutrients 2019; 11:nu11071485. [PMID: 31261904 PMCID: PMC6682936 DOI: 10.3390/nu11071485] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 06/26/2019] [Accepted: 06/27/2019] [Indexed: 11/16/2022] Open
Abstract
Oral rehydration solutions (ORS) are specifically formulated with an osmolality to optimize fluid absorption. However, it is unclear how many ORS products comply with current World Health Organization (WHO) osmolality guidelines and the osmotic shelf-life stability is not known. Therefore, the purpose of this investigation was to examine the within and between ORS product osmolality variation in both pre-mixed and reconstituted powders. Additionally, the osmotic stability was examined over time. The osmolality of five different pre-mixed solutions and six powdered ORS products were measured. Pre-mixed solutions were stored at room temperatures and elevated temperatures (31 °C) for two months to examine osmotic shelf stability. Results demonstrated that only one pre-mixed ORS product was in compliance with the current guidelines both before and after the prolonged storage. Five of the six powdered ORS products were in compliance with minimal inter-packet variation observed within the given formulations. This investigation demonstrates that many commercially available pre-mixed ORS products do not currently adhere to the WHO recommended osmolality guidelines. Additionally, due to the presence of particular sugars and possibly other ingredients, the shelf-life stability of osmolality for certain ORS products may be questioned. These findings should be carefully considered in the design of future ORS products.
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Affiliation(s)
- Kurt J Sollanek
- Department of Kinesiology, Sonoma State University, Rohnert Park, CA 94928, USA.
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5
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Schneider S, Wright CM, Heuckeroth RO. Unexpected Roles for the Second Brain: Enteric Nervous System as Master Regulator of Bowel Function. Annu Rev Physiol 2019; 81:235-259. [DOI: 10.1146/annurev-physiol-021317-121515] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
At the most fundamental level, the bowel facilitates absorption of small molecules, regulates fluid and electrolyte flux, and eliminates waste. To successfully coordinate this complex array of functions, the bowel relies on the enteric nervous system (ENS), an intricate network of more than 500 million neurons and supporting glia that are organized into distinct layers or plexi within the bowel wall. Neuron and glial diversity, as well as neurotransmitter and receptor expression in the ENS, resembles that of the central nervous system. The most carefully studied ENS functions include control of bowel motility, epithelial secretion, and blood flow, but the ENS also interacts with enteroendocrine cells, influences epithelial proliferation and repair, modulates the intestinal immune system, and mediates extrinsic nerve input. Here, we review the many different cell types that communicate with the ENS, integrating data about ENS function into a broader view of human health and disease. In particular, we focus on exciting new literature highlighting relationships between the ENS and its lesser-known interacting partners.
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Affiliation(s)
- Sabine Schneider
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Christina M. Wright
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Robert O. Heuckeroth
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Abramson Research Center, The Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania 19104, USA
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6
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Yang X, Wen G, Tuo B, Zhang F, Wan H, He J, Yang S, Dong H. Molecular mechanisms of calcium signaling in the modulation of small intestinal ion transports and bicarbonate secretion. Oncotarget 2017; 9:3727-3740. [PMID: 29423078 PMCID: PMC5790495 DOI: 10.18632/oncotarget.23197] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 12/01/2017] [Indexed: 01/13/2023] Open
Abstract
Background and Purpose: Although Ca2+ signaling may stimulate small intestinal ion secretion, little is known about its critical role and the molecular mechanisms of Ca2+-mediated biological action. Key Results Activation of muscarinic receptors by carbachol(CCh) stimulated mouse duodenal Isc, which was significantly inhibited in Ca2+-free serosal solution and by several selective store-operated Ca2+ channels(SOC) blockers added to the serosal side of duodenal tissues. Furthermore, we found that CRAC/Orai channels may represent the molecular candidate of SOC in intestinal epithelium. CCh increased intracellular Ca2+ but not cAMP, and Ca2+ signaling mediated duodenal Cl- and HCO3- secretion in wild type mice but not in CFTR knockout mice. CCh induced duodenal ion secretion and stimulated PI3K/Akt activity in duodenal epithelium, all of which were inhibited by selective PI3K inhibitors with different structures. CCh-induced Ca2+ signaling also stimulated the phosphorylation of CFTR proteins and their trafficking to the plasma membrane of duodenal epithelial cells, which were inhibited again by selective PI3K inhibitors. Materials and Methods Functional, biochemical and morphological experiments were performed to examine ion secretion, PI3K/Akt and CFTR activity of mouse duodenal epithelium. Ca2+ imaging was performed on HT-29 cells. Conclusions and Implications Ca2+ signaling plays a critical role in intestinal ion secretion via CRAC/Orai-mediated SOCE mechanism on the serosal side of epithelium. We also demonstrated the molecular mechanisms of Ca2+ signaling in CFTR-mediated secretion via novel PI3K/Akt pathway. Our findings suggest new perspectives for drug targets to protect the upper GI tract and control liquid homeostasis in the small intestine.
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Affiliation(s)
- Xin Yang
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China
| | - Guorong Wen
- Department of Gastroenterology, Affiliated Hospital, Zunyi Medical College, and Digestive Disease Institute of Guizhou Province, Zunyi 563003, China
| | - Biguang Tuo
- Department of Gastroenterology, Affiliated Hospital, Zunyi Medical College, and Digestive Disease Institute of Guizhou Province, Zunyi 563003, China
| | - Fenglian Zhang
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China
| | - Hanxing Wan
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China
| | - Jialin He
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China
| | - Shiming Yang
- Department of Gastroenterology, Affiliated Hospital, Zunyi Medical College, and Digestive Disease Institute of Guizhou Province, Zunyi 563003, China
| | - Hui Dong
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.,Department of Medicine, School of Medicine, University of California, San Diego, CA 92093, USA
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7
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High-fat diet modifies the PPAR-γ pathway leading to disruption of microbial and physiological ecosystem in murine small intestine. Proc Natl Acad Sci U S A 2016; 113:E5934-E5943. [PMID: 27638207 DOI: 10.1073/pnas.1612559113] [Citation(s) in RCA: 155] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Diet is among the most important factors contributing to intestinal homeostasis, and basic functions performed by the small intestine need to be tightly preserved to maintain health. Little is known about the direct impact of high-fat (HF) diet on small-intestinal mucosal defenses and spatial distribution of the microbiota during the early phase of its administration. We observed that only 30 d after HF diet initiation, the intervillous zone of the ileum-which is usually described as free of bacteria-became occupied by a dense microbiota. In addition to affecting its spatial distribution, HF diet also drastically affected microbiota composition with a profile characterized by the expansion of Firmicutes (appearance of Erysipelotrichi), Proteobacteria (Desulfovibrionales) and Verrucomicrobia, and decrease of Bacteroidetes (family S24-7) and Candidatus arthromitus A decrease in antimicrobial peptide expression was predominantly observed in the ileum where bacterial density appeared highest. In addition, HF diet increased intestinal permeability and decreased cystic fibrosis transmembrane conductance regulator (Cftr) and the Na-K-2Cl cotransporter 1 (Nkcc1) gene and protein expressions, leading to a decrease in ileal secretion of chloride, likely responsible for massive alteration in mucus phenotype. This complex phenotype triggered by HF diet at the interface between the microbiota and the mucosal surface was reversed when the diet was switched back to standard composition or when mice were treated for 1 wk with rosiglitazone, a specific agonist of peroxisome proliferator-activated receptor-γ (PPAR-γ). Moreover, weaker expression of antimicrobial peptide-encoding genes and intervillous bacterial colonization were observed in Ppar-γ-deficient mice, highlighting the major role of lipids in modulation of mucosal immune defenses.
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8
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Alayoubi A, Sullivan RD, Lou H, Patel H, Mandrell T, Helms R, Almoazen H. In Vivo Evaluation of Transdermal Iodide Microemulsion for Treating Iodine Deficiency Using Sprague Dawley Rats. AAPS PharmSciTech 2016; 17:618-30. [PMID: 26288943 DOI: 10.1208/s12249-015-0392-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 08/09/2015] [Indexed: 11/30/2022] Open
Abstract
The objective of this study was to evaluate the transdermal efficiency of iodide microemulsion in treating iodine deficiency using rats as an animal model. Animals were fed either iodine-deficient diet (20 μg/kg iodide) or control diet (200 μg/kg iodide) over a 17-month period. At month 14, iodide microemulsion was applied topically in iodine-deficient group and physiological evaluations of thyroid gland functions were characterized by monitoring the thyroid hormones (T3, T4), thyroid-stimulating hormone (TSH), iodide ion excretion in urine, and the overall rat body weights in both groups. Moreover, morphological evaluations of thyroid gland before and after treatment were performed by ultrasound imaging and through histological assessment. Prior to microemulsion treatment, the levels of T3, T4, and TSH in iodine-deficient group were statistically significant as compared to that in the control group. The levels of T3 and T4 increased while TSH level decreased significantly in iodine-deficient group within the first 4 weeks of treatment. After treatment, iodide concentration in urine increased significantly. There was no statistical difference in weight between the two groups. Ultrasound imaging and histological evaluations showed evidence of hyperplasia in iodine-deficient group. Topical iodide microemulsion has shown a promising potential as a novel delivery system to treat iodine deficiency.
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9
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Reineke EL, Walton K, Otto CM. Evaluation of an oral electrolyte solution for treatment of mild to moderate dehydration in dogs with hemorrhagic diarrhea. J Am Vet Med Assoc 2016; 243:851-7. [PMID: 24004233 DOI: 10.2460/javma.243.6.851] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine the safety and efficacy of an electrolyte solution for oral administration (OES) for the correction of mild to moderate dehydration associated with hemorrhagic diarrhea in dogs. DESIGN Nonrandomized, noncontrolled clinical trial. ANIMALS 20 dogs that had hemorrhagic diarrhea with < 3 episodes of vomiting. PROCEDURES All dogs underwent testing for parvovirus infection, were given maropitant citrate to control emesis, and were offered an OES. Intravenous crystalloid fluid administration was performed when dogs refused the OES or had vomiting, a 5% increase in PCV, 5% decrease in body weight, serum creatinine or BUN concentration higher than at admission, or clinically important alterations in blood electrolyte or serum glucose concentrations. RESULTS 13 (65%) dogs voluntarily consumed the OES; 7 (35%) dogs refused the OES and received a balanced electrolyte solution IV instead. All 13 dogs in the OES group consumed the solution ≤ 5 hours after hospital admission. Eight and 16 hours after admission, PCV and serum total protein and BUN concentrations were significantly lower than at hospital admission in the OES group, whereas no significant changes were identified in venous blood pH, base excess, and concentrations of sodium, potassium, chloride, ionized calcium, ionized magnesium, and lactate. The cost of treatment was significantly less for the OES group than for the IV treated group. CONCLUSIONS AND CLINICAL RELEVANCE Rehydration therapy with an OES was effective and safe in dogs with mild to moderate dehydration associated with hemorrhagic diarrhea. Potential benefits of this treatment approach for gastroenteritis in dogs, compared with traditional IV fluid administration, include lower owner-related veterinary costs and decreased staff time associated with treatment.
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Affiliation(s)
- Erica L Reineke
- Department of Clinical Studies-Philadelphia, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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10
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Abstract
The objective of this article is to provide a review of the fundamental aspects of body fluid balance and the physiological consequences of water imbalances, as well as discuss considerations for the optimal composition of a fluid replacement beverage across a broad range of applications. Early pioneering research involving fluid replacement in persons suffering from diarrheal disease and in military, occupational, and athlete populations incurring exercise- and/or heat-induced sweat losses has provided much of the insight regarding basic principles on beverage palatability, voluntary fluid intake, fluid absorption, and fluid retention. We review this work and also discuss more recent advances in the understanding of fluid replacement as it applies to various populations (military, athletes, occupational, men, women, children, and older adults) and situations (pathophysiological factors, spaceflight, bed rest, long plane flights, heat stress, altitude/cold exposure, and recreational exercise). We discuss how beverage carbohydrate and electrolytes impact fluid replacement. We also discuss nutrients and compounds that are often included in fluid-replacement beverages to augment physiological functions unrelated to hydration, such as the provision of energy. The optimal composition of a fluid-replacement beverage depends upon the source of the fluid loss, whether from sweat, urine, respiration, or diarrhea/vomiting. It is also apparent that the optimal fluid-replacement beverage is one that is customized according to specific physiological needs, environmental conditions, desired benefits, and individual characteristics and taste preferences.
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11
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Song P, Du Y, Song W, Liu X, Hong L, Li H, Xie H, Zhou L, Tuo B, Zheng S. Bile deficiency induces changes in intestinal Cl(-) and HCO3 (-) secretions in mice. Acta Physiol (Oxf) 2014; 211:421-33. [PMID: 24731192 DOI: 10.1111/apha.12301] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 08/28/2013] [Accepted: 04/10/2014] [Indexed: 12/14/2022]
Abstract
AIMS Biliary tract obstruction is a common clinical lesion. However, the effect of biliary tract obstruction on intestinal secretion is poorly understood. In this study, we made an investigation on intestinal HCO3 (-) and Cl(-) secretions in an experimental model of murine biliary duct ligation. METHODS Murine intestinal mucosal HCO3 (-) and Cl(-) secretions were examined in vitro in Ussing chambers by pH-stat and short-circuit current (Isc ) techniques. The mRNA and protein expressions of the cystic fibrosis transmembrane conductance regulator (CFTR) and the Na(+) -K(+) -2Cl(-) cotransporter (NKCC1) were analysed by real-time PCR, western blot and immunohistochemistry. RESULTS Basal Cl(-) secretion and forskolin-stimulated duodenal and jejunal mucosal HCO3 (-) and Cl(-) secretions in mice with common biliary duct ligation were markedly elevated, compared with controls (P < 0.05 and P < 0.01). Further experiments showed that basal Cl(-) secretion and forskolin-stimulated duodenal and jejunal mucosal HCO3 (-) and Cl(-) secretions in mice with external bile drainage were also markedly elevated. CFTRinh -172 inhibited forskolin-stimulated HCO3 (-) and Cl(-) secretions. The mRNA and protein expression levels of CFTR and NKCC1 in the intestinal mucosa with both biliary duct ligation and external bile drainage were markedly higher than those in controls (P < 0.001). Bile acid administration restored the changes in function and expression of CFTR and NKCC1 in the intestinal mucosa. CONCLUSION Bile deficiency in the intestine up-regulates the expressions of intestinal mucosal CFTR and NKCC1 and enhances intestinal mucosal HCO3 (-) and Cl(-) secretion capacity, which contributes to the understanding of intestinal physiological function for patients with biliary duct obstruction.
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Affiliation(s)
- P. Song
- Key Laboratory of Combined Multi-organ Transplantation; Ministry of Public Health; First Affiliated Hospital; School of Medicine; Zhejiang University; Hangzhou 310003 China
| | - Y. Du
- Key Laboratory of Combined Multi-organ Transplantation; Ministry of Public Health; First Affiliated Hospital; School of Medicine; Zhejiang University; Hangzhou 310003 China
| | - W. Song
- Key Laboratory of Combined Multi-organ Transplantation; Ministry of Public Health; First Affiliated Hospital; School of Medicine; Zhejiang University; Hangzhou 310003 China
| | - X. Liu
- Department of Surgery; First Affiliated Hospital; School of Medicine; Zhejiang University; Hangzhou 310003 China
| | - L. Hong
- Key Laboratory of Combined Multi-organ Transplantation; Ministry of Public Health; First Affiliated Hospital; School of Medicine; Zhejiang University; Hangzhou 310003 China
| | - H. Li
- Key Laboratory of Combined Multi-organ Transplantation; Ministry of Public Health; First Affiliated Hospital; School of Medicine; Zhejiang University; Hangzhou 310003 China
| | - H. Xie
- Key Laboratory of Combined Multi-organ Transplantation; Ministry of Public Health; First Affiliated Hospital; School of Medicine; Zhejiang University; Hangzhou 310003 China
| | - L. Zhou
- Key Laboratory of Combined Multi-organ Transplantation; Ministry of Public Health; First Affiliated Hospital; School of Medicine; Zhejiang University; Hangzhou 310003 China
| | - B. Tuo
- Department of Gastroenterology; Affiliated Hospital of Zunyi Medical College; Zunyi 563003 China
| | - S. Zheng
- Key Laboratory of Combined Multi-organ Transplantation; Ministry of Public Health; First Affiliated Hospital; School of Medicine; Zhejiang University; Hangzhou 310003 China
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12
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Wall EA. An overview of short bowel syndrome management: adherence, adaptation, and practical recommendations. J Acad Nutr Diet 2013; 113:1200-8. [PMID: 23830324 DOI: 10.1016/j.jand.2013.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Accepted: 04/30/2013] [Indexed: 12/14/2022]
Abstract
Short bowel syndrome (SBS) refers to the clinical consequences resulting from loss of small bowel absorptive surface area due to surgical resection or bypass. The syndrome is characterized by maldigestion, malabsorption, and malnutrition. Survival of patients with SBS is dependent on adaptation in the remaining bowel and a combination of pharmacologic and nutrition therapies. Individual plans of care are developed based on the length and sites of remaining bowel, the degree of intestinal adaptation, and the patient's ability to adhere to the medication and dietary regimens. Antisecretory and antidiarrheal medications are prescribed to slow intestinal transit times and optimize fluid and nutrient absorption. Based on postsurgical anatomy, enteral feedings, parenteral infusions, complex diet plans, and vitamin and mineral supplementation are used in various combinations to nourish patients with SBS. In the acute care setting, registered dietitians (RDs) assist with infusion therapy, diet education, and discharge planning. Long-term, as the small intestine adapts, RDs revise the nutrition care plan and monitor for nutrient deficiencies, metabolic bone disease, and anemia. The frequent monitoring and revision of care plans, plus the appreciable benefits from proper medical nutrition therapy, make this patient population extremely challenging and rewarding for RDs to manage. This article provides a brief, case study-based overview of the medical and nutrition management of SBS.
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13
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Song P, Song W, Liu X, Jin C, Xie H, Zhou L, Tuo B, Zheng S. Function and expression of cystic fibrosis transmembrane conductance regulator after small intestinal transplantation in mice. PLoS One 2013; 8:e62536. [PMID: 23626828 PMCID: PMC3633864 DOI: 10.1371/journal.pone.0062536] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 03/22/2013] [Indexed: 01/14/2023] Open
Abstract
The secretion function of intestinal graft is one of the most important factors for successful intestinal transplantation. Cystic fibrosis transmembrane conductance regulator (CFTR) mediates HCO3- and Cl- secretions in intestinal epithelial cells. In this study, we made investigation on the expression and function of CFTR in an experimental model of murine small intestinal transplantation. Heterotopic intestinal transplantations were performed in syngeneic mice. The mRNA and protein expressions of CFTR were analyzed by real time PCR and western blot. Murine intestinal mucosal HCO3- and Cl- secretions were examined in vitro in Ussing chambers by the pH stat and short circuit current (Isc) techniques. The results showed that forskolin, an activator of CFTR, stimulated jejunal mucosal epithelial HCO3- and Cl- secretions in mice, but forskolin-stimulated HCO3- and Cl- secretions in donor and recipient jejunal mucosae of mice after heterotopic jejunal transplantation were markedly decreased, compared with controls (P<0.001). The mRNA and protein expression levels of CFTR in donor and recipient jejunal mucosae of mice were also markedly lower than those in controls (P<0.001), and the mRNA and protein expression levels of tumor necrosis factor α (TNFα) were markedly increased in donor jejunal mucosae of mice (P<0.001), compared with controls. Further experiments showed that TNFα down-regulated the expression of CFTR mRNA in murine jejunal mucosa. In conclusion, after intestinal transplantation, the function of CFTR was impaired, and its mRNA and protein expressions were down-regulated, which may be induced by TNFα.
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Affiliation(s)
- Penghong Song
- Key Laboratory of Combined Multi-organ Transplantation of Ministry of Public Health, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Wenfeng Song
- Key Laboratory of Combined Multi-organ Transplantation of Ministry of Public Health, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiaosun Liu
- Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Changhai Jin
- Key Laboratory of Combined Multi-organ Transplantation of Ministry of Public Health, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Haiyang Xie
- Key Laboratory of Combined Multi-organ Transplantation of Ministry of Public Health, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Lin Zhou
- Key Laboratory of Combined Multi-organ Transplantation of Ministry of Public Health, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Biguang Tuo
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical College, Zunyi, China
| | - Shusen Zheng
- Key Laboratory of Combined Multi-organ Transplantation of Ministry of Public Health, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- * E-mail:
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14
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Grünberg W, Hartmann H, Arlt S, Burfeind O, Staufenbiel R. Alkalinizing effect of NaHCO₃ with and without glucose when administered orally to euhydrated neonatal dairy calves. J Dairy Sci 2013; 96:3895-906. [PMID: 23548282 DOI: 10.3168/jds.2012-6202] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 02/12/2013] [Indexed: 01/27/2023]
Abstract
The use of oral rehydration solutions (ORS) is well established as an effective treatment to correct water-, electrolyte-, and acid-base balance in diarrheic calves. The main ingredients of a commercial ORS are Na, glucose, and alkalinizing agents, such as NaHCO3. Particular importance is attributed to the combination of glucose and Na at a specific ratio to optimize intestinal sodium, and thereby water uptake, through the sodium-glucose co-transport. Enhancing intestinal Na absorption by combining glucose and Na in an ORS has the potential to improve the alkalinizing effect of an ORS according the strong ion theory. The objective of this study was to investigate the effect of glucose on the alkalinizing effect of NaHCO3 when administered orally. Nine healthy neonatal Holstein-Friesian calves underwent 3 oral treatments with 2-L solutions of NaHCO3 (150 mmol/L), glucose (300 mmol/L), and glucose + NaHCO3 (300 mmol/L + 150 mmol/L, respectively) in randomized order. Arterial and venous blood was obtained before treatment and in 30-min intervals thereafter for blood gas analysis and determination of plasma protein and electrolyte concentrations. Urine was collected volumetrically to determine urine volume, osmolality, pH, net acid excretion, and renal Na excretion after treatment. Plasma volume changes were extrapolated from plasma protein concentration changes. Treatment and time effects were tested with repeated measures ANOVA. Only subtle differences between oral administration of NaHCO3, with and without glucose, were observed for the change of the standard HCO3 concentration relative to baseline. No differences in plasma Na, plasma volume expansion, renal Na, net base excretion, urine volume, or pH could be identified between animals treated orally with NaHCO3 with and without glucose. Similarly, no differences in blood glucose concentration, plasma volume expansion, urine volume, or renal glucose excretion were observed in the 8h after treatment when comparing oral glucose treatment with and without NaHCO3. Our results indicate that combination of NaHCO3 with glucose in a hypertonic ORS only had a minor effect on the alkalinizing effect of NaHCO3, which is unlikely to be of clinical relevance. The combination of NaHCO3 and glucose neither improved Na, glucose, nor water absorption in euhydrated neonatal dairy calves, questioning the relevance of a specific ratio between Na and glucose in ORS for calves.
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Affiliation(s)
- W Grünberg
- Department of Farm Animal Health, Universiteit Utrecht, Utrecht, The Netherlands.
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15
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Charoenphandhu N, Laohapitakworn S, Kraidith K, Nakkrasae LI, Jongwattanapisan P, Tharabenjasin P, Krishnamra N. Electrogenic Na+/HCO3- co-transporter-1 is essential for the parathyroid hormone-stimulated intestinal HCO3- secretion. Biochem Biophys Res Commun 2011; 409:775-9. [DOI: 10.1016/j.bbrc.2011.05.087] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 05/14/2011] [Indexed: 01/26/2023]
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16
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Atia A, Buchman AL. Treatment of cholera-like diarrhoea with oral rehydration. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2011; 104:465-74. [PMID: 20863435 DOI: 10.1179/136485910x12786389891164] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Cholera diarrhoea remains a major global health problem that has caused seven pandemics. The pathogenesis of cholera is attributable to the production of cholera toxin by the causative pathogen, Vibrio cholerae. The toxin causes increased production of cyclic adenosine monophosphate and this results in massive water and electrolyte secretion into the intestinal lumen. These changes manifest clinically as the painless defecation of voluminous stools that resemble 'rice water', leading to severe dehydration. The cornerstone in the management of cholera diarrhoea is the use of oral rehydration solutions (ORS) to replace the water and electrolytes lost as stools. The World Health Organization recommends the use of ORS of 'reduced osmolarity' for the treatment of acute non-cholera diarrhoea and the use of rice-based ORS for the management of cholera diarrhoea. Although several attempts have been made to improve ORS, studies to evaluate some of the modifications, which include the addition of amylase-resistant starch, the use of amino acids (such as glycine, alanine and glutamine) as sodium cotransporters, and zinc-supplemented ORS, are still needed.
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Affiliation(s)
- A Atia
- Department of Infectious Diseases, East Tennessee State University, Johnson City, TN 37614, USA
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17
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Suh JS, Hahn WH, Cho BS. Recent Advances of Oral Rehydration Therapy (ORT). Electrolyte Blood Press 2010; 8:82-6. [PMID: 21468201 PMCID: PMC3043760 DOI: 10.5049/ebp.2010.8.2.82] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 11/24/2010] [Indexed: 12/14/2022] Open
Abstract
Diarrheal disease is one of the leading causes of worldwide morbidity and mortality, especially in children. It causes loss of body fluid, which may lead to severe dehydration, electrolyte imbalance, shock and even to death. The mortality rate from acute diarrhea has decreased over the last few decades. This decline, especially in developing countries is largely due to the implantation of the standard World Health Organization-oral rehydration solution (WHO-ORS). However, the use of standard ORS has been limited by its inability to reduce fecal volume or diarrhea duration. Subsequently, this has led to various attempts to modify its compositions. And these modifications include the use of reduced osmolarity ORS, polymer-based ORS and zinc supplementation. Some of these variations have been successful and others are still under investigation. Therefore, further trials are needed to progress toward the ideal ORS. In this article, we briefly reviewed the pathophysiologic basis of the ORS, followed by the standard WHO-ORS and several modifications to improve the ORS.
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Affiliation(s)
- Jin-Soon Suh
- Department of Pediatrics, East West Kidney Disease Institute, School of Medicine, Kyung Hee University, Seoul, Korea
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18
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Genistein stimulates duodenal HCO(3)(-) secretion through PI3K pathway in mice. Eur J Pharmacol 2010; 651:159-67. [PMID: 21093426 DOI: 10.1016/j.ejphar.2010.10.070] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 10/10/2010] [Accepted: 10/29/2010] [Indexed: 11/20/2022]
Abstract
Genistein has been proposed as a promising pharmacotherapeutic for cystic fibrosis. We recently found that genistein stimulates murine duodenal HCO(3)(-) secretion through cystic fibrosis transmembrane conductance regulator (CFTR). The aim of the present study was to determine the intracellular signal pathways involved in genistein-stimulated duodenal HCO(3)(-) secretion. Murine duodenal mucosal HCO(3)(-) secretion was examined in vitro in Ussing chambers by the pH-stat technique. The results showed that neither cAMP-dependent signal pathway inhibitors MDL-12330A and KT-5720, nor cGMP signal pathway inhibitors NS2028 and KT5823, nor calcium signal pathway inhibitors verapamil and W-13, altered genistein-stimulated duodenal HCO(3)(-) secretion. In calcium-free solution, genistein-stimulated duodenal HCO(3)(-) secretion was not altered either. Vanadate, an inhibitor of protein tyrosine phosphatase, only partially inhibited genistein-stimulated duodenal HCO(3)(-) secretion. However, both wortmannin and LY294002, two structurally and mechanistically distinct phosphatidylinositol 3-kinase (PI3K) inhibitors, markedly inhibited genistein-stimulated duodenal HCO(3)(-) secretion. Genistein increased duodenal mucosal PI3K activity and induced the phosphorylation of Akt, a signaling molecule downstream of PI3K, which was again inhibited by wortmannin. Estrogen receptor antagonist, ICI182,780, also markedly inhibited genistein-stimulated duodenal HCO(3)(-) secretion and genistein-induced PI3K activity increase in duodenal mucosa. These results demonstrate that genistein stimulates duodenal HCO(3)(-) secretion mainly through estrogen receptor and PI3K-dependent pathway. These findings contribute to the understanding of the molecular mechanism of genistein-induced anion secretion and further pharmacotherapeutic development and use of genistein or related substances in the treatment of diseases of epithelial tissues.
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19
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Atia AN, Buchman AL. Oral rehydration solutions in non-cholera diarrhea: a review. Am J Gastroenterol 2009; 104:2596-604; quiz 2605. [PMID: 19550407 DOI: 10.1038/ajg.2009.329] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The use of oral rehydration solution (ORS) has revolutionized the management of acute diarrhea. The implementation of the standard World Health Organization ORS (WHO-ORS) has resulted in decreased mortality associated with acute diarrheal illnesses in children, although in general stool volume and diarrhea durations are not reduced. Decreased morbidity and mortality have occurred because of improved hydration status. Decreased morbidity has also been described in adults who used this therapy. Various modifications to the standard ORS have been derived. These modifications have included hypo-osmolar or hyperosmolar solutions, use of rice-based ORS, zinc supplementation, and the use of amino acids, including glycine, alanine, and glutamine. Some of these variations have been successful, some have not, and others are still under investigation. ORS has been used for travelers' diarrhea and to decrease intravenous (IV) fluid requirements in patients with short bowel syndrome (SBS) who require parenteral nutrition (PN). This paper reviews the standard WHO-ORS and its mechanism of action, followed by more contemporary reduced osmolarity ORS and rice-based ORS in non-cholera diarrhea. Various modifications to improve ORS are also discussed.
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Affiliation(s)
- Antwan N Atia
- Department of Internal Medicine, East Tennessee State University, Johnson City, Tennessee, USA
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20
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Tuo B, Wen G, Seidler U. Differential activation of the HCO(3)(-) conductance through the cystic fibrosis transmembrane conductance regulator anion channel by genistein and forskolin in murine duodenum. Br J Pharmacol 2009; 158:1313-21. [PMID: 19788494 DOI: 10.1111/j.1476-5381.2009.00398.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Many cystic fibrosis (CF)-associated mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) anion channels affect CFTR-activated HCO(3)(-) transport more than Cl(-) transport. Targeting the CFTR HCO(3)(-) conductance, if possible, may therefore be of major therapeutic benefit. In the present study, we examined the effects of genistein and forskolin on duodenal mucosal HCO(3)(-) and Cl(-) secretion. EXPERIMENTAL APPROACH Murine duodenal mucosal HCO(3)(-) and Cl(-) secretions were examined in vitro in Ussing chambers by the pH stat and short circuit current (I(sc)) techniques. KEY RESULTS Genistein markedly stimulated duodenal HCO(3)(-) secretion and I(sc) in a dose-dependent manner in CFTR wild-type mice, but not in CFTR null mice. CFTR(inh)-172, a highly specific CFTR inhibitor, inhibited genistein-stimulated duodenal HCO(3)(-) secretion and I(sc) in wild-type mice. Genistein induced 59% net HCO(3)(-) increase and 123% net I(sc) increase over basal value, whereas forskolin, an activator of adenylate cyclase, induced 94% net HCO(3)(-) increase and 507% net I(sc) increase, indicating that, compared with forskolin, genistein induced a relatively high HCO(3)(-)/I(sc) ratio. Further data showed that CFTR HCO(3)(-)/Cl(-) conductance ratio was 1.05 after genistein stimulation, whereas after forskolin stimulation, the CFTR HCO(3)(-)/Cl(-) conductance ratio was 0.27. CONCLUSIONS AND IMPLICATIONS Genistein stimulates duodenal HCO(3)(-) and Cl(-) secretion through CFTR, and has a relatively high selectivity for the CFTR HCO(3)(-) conductance, compared with forskolin. This may indicate the feasibility of selective targeting of the HCO(3)(-) conductance of the CFTR channels.
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Affiliation(s)
- Biguang Tuo
- Department of Gastroenterology, Affiliated Hospital, Zunyi Medical College, Zunyi, China.
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Tuo B, Wen G, Zhang Y, Liu X, Wang X, Liu X, Dong H. Involvement of phosphatidylinositol 3-kinase in cAMP- and cGMP-induced duodenal epithelial CFTR activation in mice. Am J Physiol Cell Physiol 2009; 297:C503-15. [PMID: 19535511 DOI: 10.1152/ajpcell.00460.2008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although phosphatidylinositol 3-kinase (PI3K) is essential for several cellular signal transductions, its role in the regulation of cystic fibrosis transmembrane conductance regulator (CFTR) activity in intestinal epithelial cells is poorly understood. Therefore, the possible involvement of PI3K in the regulation of cAMP- and cGMP-induced duodenal epithelial CFTR activation was investigated in the present study. Forskolin and 8-bromoguanosine 3',5'-cyclic monophosphate (8-Br-cGMP) markedly stimulated duodenal mucosal HCO(3)(-) secretion and short-circuit current (I(sc)) in CFTR wild-type mice, which was significantly inhibited by CFTR(inh)-172, a highly potent and specific CFTR inhibitor. Forskolin and 8-Br-cGMP failed to stimulate duodenal HCO(3)(-) secretion and I(sc) in CFTR knockout mice. Moreover, forskolin- and 8-Br-cGMP-stimulated duodenal HCO(3)(-) secretion and I(sc) were significantly reduced by wortmannin and LY294002, two selective PI3K inhibitors that are structurally and mechanistically different. Forskolin and 8-Br-cGMP induced CFTR phosphorylation and shifted CFTR proteins to the plasma membrane of duodenal epithelial cells, which were inhibited by wortmannin and LY294002. Forskolin and 8-Br-cGMP not only increased the activity of PI3K but also induced the phosphorylation of Akt, a signaling molecule downstream of PI3K, which were again inhibited by wortmannin and LY294002. Together, our results obtained from functional, biochemical, and morphological studies demonstrate that PI3K pathway plays an important role in the regulation of cAMP- and cGMP-induced duodenal epithelial CFTR channel activity and intracellular trafficking.
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Affiliation(s)
- Biguang Tuo
- Dept. of Gastroenterology, Affiliated Hospital of Zunyi Medical College, Dalian Road 149, Zunyi 563003, China.
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Heitzmann D, Warth R. Physiology and pathophysiology of potassium channels in gastrointestinal epithelia. Physiol Rev 2008; 88:1119-82. [PMID: 18626068 DOI: 10.1152/physrev.00020.2007] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Epithelial cells of the gastrointestinal tract are an important barrier between the "milieu interne" and the luminal content of the gut. They perform transport of nutrients, salts, and water, which is essential for the maintenance of body homeostasis. In these epithelia, a variety of K(+) channels are expressed, allowing adaptation to different needs. This review provides an overview of the current literature that has led to a better understanding of the multifaceted function of gastrointestinal K(+) channels, thereby shedding light on pathophysiological implications of impaired channel function. For instance, in gastric mucosa, K(+) channel function is a prerequisite for acid secretion of parietal cells. In epithelial cells of small intestine, K(+) channels provide the driving force for electrogenic transport processes across the plasma membrane, and they are involved in cell volume regulation. Fine tuning of salt and water transport and of K(+) homeostasis occurs in colonic epithelia cells, where K(+) channels are involved in secretory and reabsorptive processes. Furthermore, there is growing evidence for changes in epithelial K(+) channel expression during cell proliferation, differentiation, apoptosis, and, under pathological conditions, carcinogenesis. In the future, integrative approaches using functional and postgenomic/proteomic techniques will help us to gain comprehensive insights into the role of K(+) channels of the gastrointestinal tract.
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Affiliation(s)
- Dirk Heitzmann
- Institute of Physiology and Clinic and Policlinic for Internal Medicine II, Regensburg, Germany
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Jahraus CD, Brandt S, Bettenhausen D. Recognizing and treating a new entity on the quality-of-life front: small intestinal bacterial overgrowth. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/s1548-5315(11)70044-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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