scholarly journals Direct Effect of Lipopolysaccharide and Histamine on Permeability Barrier of Rumen Epithelium

2021 ◽  
Author(s):  
Shengtao Gao ◽  
Alateng Zhula ◽  
Wenhui Liu ◽  
Zhongyan Lu ◽  
Zanming Shen ◽  
...  
Keyword(s):  
Direct Effect ◽  
Barrier Function ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Permeability Barrier ◽  
Apparent Permeability ◽  
Direct Role ◽  
Rumen Epithelium ◽  
Ruminal Epithelium ◽  
The Individual

Abstract Background: Disruption of the ruminal epithelium barrier occurs during subacute ruminal acidosis due to low pH, hyper-osmolality, and increased concentrations of lipopolysaccharide and histamine in ruminal fluid. However, the individual roles of lipopolysaccharide and histamine in the process of ruminal epithelium barriers disruption are not clear. The objective of the present investigation was to evaluate the direct effect of lipopolysaccharide and histamine on barrier function of the ruminal epithelium. Results: Compared with control (CON), lipopolysaccharide (HIS) increased the short-circuit current (Isc) (88.2%, P = 0.0022), transepithelial conductance (Gt) (29.7%, P = 0.0564) and the permeability of fluorescein 5(6)-isothiocyanate (FITC) (1.04-fold, P = 0.0047) of ruminal epithelium. The apparent permeability of LPS was 1.81-fold higher than HIS (P = 0.0005). The mRNA abundance of OCLN in ruminal epithelium was decreased by HIS (1.1-fold, P = 0.0473). Conclusions: The results of the present study suggested that histamine plays a direct role in the disruption of ruminal epithelium barrier function while lipopolysaccharide without acidic pH has no significant effect on the permeability of rumen tissues.

scholarly journals Coupling of epithelial Na+ and Cl− channels by direct and indirect activation by serine proteases

2012 ◽  
Vol 303 (9) ◽  
pp. C936-C946 ◽  
Author(s):  
Veronika Gondzik ◽  
Wolf Michael Weber ◽  
Mouhamed S. Awayda
Keyword(s):  
Serine Proteases ◽  
Collecting Duct ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Epithelial Cell Line ◽  
Extracellular Proteases ◽  
Direct Role ◽  
Renal Epithelial Cell ◽  
Transport Pathways

The mammalian collecting duct (CD) is continuously exposed to urinary proteases. The CD expresses an epithelial Na+ channel (ENaC) that is activated after cleavage by serine proteases. ENaC also exists at the plasma membrane in the uncleaved form, rendering activation by extracellular proteases an important mechanism for regulating Na+ transport. Many exogenous and a small number of endogenous extracellular serine proteases have been shown to activate the channel. Recently, kallikrein 1 (KLK1) was shown to increase γENaC cleavage in the native CD indicating a possible direct role of this endogenous protease in Na+ homeostasis. To explore this process, we examined the coordinated effect of this protease on Na+ and Cl− transport in a polarized renal epithelial cell line (Madin-Darby canine kidney). We also examined the role of native urinary proteases in this process. Short-circuit current ( Isc) was used to measure transport of these ions. The Isc exhibited an ENaC-dependent Na+ component that was amiloride blockable and a cystic fibrosis transmembrane conductance regulator (CFTR)-dependent Cl− component that was blocked by inhibitor 172. Apical application of trypsin, an exogenous S1 serine protease, activated IENaC but was without effects on ICFTR. Subtilisin an exogenous S8 protease that mimics endogenous furin-type proteases activated both currents. A similar activation was also observed with KLK1 and native rat urinary proteases. Activation with urinary proteases occurred within minutes and at protease concentrations similar to those in the CD indicating physiological significance of this process. ENaC activation was irreversible and mediated by enhanced cleavage of γENaC. The activation of CFTR was indirect and likely dependent on activation of an endogenous apical membrane protease receptor. Collectively, these data demonstrate coordinated stimulation of separate Na+ and Cl− transport pathways in renal epithelia by extracellular luminal proteases. They also indicate that baseline urinary proteolytic activity is sufficient to modify Na+ and Cl− transport in these epithelia.

Human colonic subepithelial myofibroblasts modulate transepithelial resistance and secretory response

1999 ◽  
Vol 277 (2) ◽  
pp. C271-C279 ◽  
Author(s):  
J. Beltinger ◽  
B. C. McKaig ◽  
S. Makh ◽  
W. A. Stack ◽  
C. J. Hawkey ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Barrier Function ◽  
Transforming Growth Factor ◽  
Short Circuit ◽  
Primary Cultures ◽  
Short Circuit Current ◽  
Transforming Growth Factor Β ◽  
Secretory Response ◽  
Transepithelial Resistance ◽  
T84 Cells

The epithelium of the gastrointestinal tract transports ions and water but excludes luminal microorganisms and toxic molecules. The factors regulating these important functions are not fully understood. Intestinal myofibroblasts lie subjacent to the basement membrane, at the basal surface of epithelial cells. We recently showed that primary cultures of adult human colonic subepithelial myofibroblasts express cyclooxygenase (COX)-1 and COX-2 enzymes and release bioactive transforming growth factor-β (TGF-β). In this study we have investigated the role of normal human colonic subepithelial myofibroblasts in the regulation of transepithelial resistance and secretory response in HCA-7 and T84 colonic epithelial cell lines. Cocultures of epithelial cells-myofibroblasts and medium conditioned by myofibroblasts enhanced transepithelial resistance and delayed mannitol flux. A panspecific antibody to TGF-β (but not piroxicam) antagonized this effect. In HCA-7 cells, myofibroblasts downregulated secretagogue-induced change in short-circuit current, and this effect was reversed by pretreatment of myofibroblasts with piroxicam. In contrast to HCA-7 cells, myofibroblasts upregulated the agonist-induced secretory response in T84 cells. This study shows that intestinal subepithelial myofibroblasts enhance barrier function and modulate electrogenic chloride secretion in epithelial cells. The enhancement of barrier function was mediated by TGF-β. In contrast, the modulation of agonist-induced change in short-circuit current was mediated by cyclooxygenase products. These findings suggest that colonic myofibroblasts regulate important functions of epithelial cells via distinct secretory products.

scholarly journals Butyrate Permeation across the Isolated Ovine Reticulum Epithelium

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2198
Author(s):  
Reiko Rackwitz ◽  
Franziska Dengler ◽  
Gotthold Gäbel
Keyword(s):  
Fatty Acids ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Chain Fatty Acids ◽  
Monocarboxylate Transporters ◽  
Buffer Solution ◽  
Mean Values ◽  
Ussing Chambers ◽  
Rumen Epithelium ◽  
The Mean

We hypothesized that, due to the high pH of this compartment, the reticulum epithelium displays particular features in the transport of short-chain fatty acids (SCFA). Ovine reticulum epithelium was incubated in Ussing chambers using a bicarbonate-free buffer solution containing butyrate (20 mmol L−1). p-hydroxymercuribenzoic acid (pHMB), 5-(N-Ethyl-N-isopropyl)amiloride (EIPA), or ouabain were added to the buffer solution as inhibitors of monocarboxylate transporters, sodium-proton-exchangers, or the Na+/K+-ATPase, respectively. The short-circuit current (Isc) and transepithelial conductance (Gt) were monitored continuously while the flux rates of 14C-labelled butyrate were measured in the mucosal-to-serosal (Jmsbut) or serosal-to-mucosal direction (Jsmbut). Under control conditions, the mean values of Isc and Gt amounted to 2.54 ± 0.46 µEq cm−2 h−1 and 6.02 ± 3.3 mS cm−2, respectively. Jmsbut was 2.1 ± 1.01 µmol cm−2 h−1 on average and about twice as high as Jsmbut. Incubation with ouabain reduced Jmsbut, while Jsmbut was not affected. The serosal addition of EIPA did not affect Jmsbut but reduced Jsmbut by about 10%. The addition of pHMB to the mucosal or serosal solution reduced Jmsbut but had no effect on Jsmbut. Mucosally applied pHMB provoked a transient increase in the Isc. The serosal pHMB sharply reduced Isc. Our results demonstrate that butyrate can be effectively transported across the reticulum epithelium. The mechanisms involved in this absorption differ from those known from the rumen epithelium.

Ion transport across rumen and omasum epithelium

1971 ◽  
Vol 262 (842) ◽  
pp. 301-305 ◽  
Keyword(s):  
Active Transport ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Chloride Ions ◽  
Rumen Epithelium ◽  
Sodium Flux ◽  
Sodium System ◽  
Chloride Pump ◽  
Net Flux ◽  
Cattle And Sheep

The interior of the rumen in cattle and sheep is normally maintained at a potential of about — 40 mV relative to the blood. This potential depends primarily on the occurrence of an active transport of sodium from rumen to blood, since the potential, short-circuit current and the net sodium flux are simultaneously abolished by anoxia, ouabain and removal of sodium from the bathing solutions. There is an appreciable net flux of potassium from blood to rumen. There is also a substantial active transport of chloride in the same direction as sodium and it can be reduced by treatment with acetazolamide without affecting the potential or the sodium system. Nevertheless, sodium transport is reduced by the removal of chloride ions. Omasum epithelium is similar to rumen epithelium. However, the chloride pump appears to work in both directions in this tissue. Short-circuited omasum epithelium can also transport magnesium from omasum to blood.

Prostaglandin-mediated inhibition of Na+/H+ exchanger isoform 2 stimulates recovery of barrier function in ischemia-injured intestine

2006 ◽  
Vol 291 (5) ◽  
pp. G885-G894 ◽  
Author(s):  
Adam J. Moeser ◽  
Prashant K. Nighot ◽  
Kathleen A. Ryan ◽  
Jenna G. Wooten ◽  
Anthony T. Blikslager
Keyword(s):  
Barrier Function ◽  
Intestinal Ischemia ◽  
Short Circuit ◽  
Intestinal Barrier ◽  
Short Circuit Current ◽  
Selective Inhibition ◽  
Ileal Mucosa ◽  
Ussing Chambers ◽  
Nhe Isoforms

Prostaglandins stimulate repair of the ischemia-injured intestinal barrier in the porcine ileum through a mechanism involving cAMP-dependent Cl− secretion and inhibition of electroneutral Na+/H+ exchanger (NHE) activity. In the present study, we focused on the role of individual NHE isoforms in the recovery of barrier function. Ischemia-injured porcine ileal mucosa was mounted on Ussing chambers. Short-circuit current ( Isc), transepithelial electrical resistance (TER), and isotopic fluxes of 22Na were measured in response to PGE2 and selective inhibitors of epithelial NHE isoforms. Immunoassays were used to assess the expression of NHE isoforms. Forty-five minutes of intestinal ischemia resulted in a 45% reduction in TER ( P < 0.01). Near-complete restitution occurred within 60 min. Inhibition of NHE2 with HOE-694 (25 μM) added to the mucosal surface of the injured ileum stimulated significant elevations in TER, independent of changes in Isc and histological evidence of restitution. Pharmacological inhibition of NHE3 or NHE1 with mucosal S-3226 (20 μM) or serosal cariporide (25 μM), respectively, had no effect. Ischemia-injured tissues treated with mucosal S-3226 or HOE-694 exhibited equivalent reductions in mucosal-to-serosal fluxes of 22Na+ (by ∼35%) compared with nontreated ischemia-injured control tissues ( P < 0.05). Intestinal ischemia resulted in increased expression of the cytoplasmic NHE regulatory factor EBP50 in NHE2 but not in NHE3 immunoprecipitates. Selective inhibition of NHE2, and not NHE3, induces recovery of barrier function in the ischemia-injured intestine.

Effect of chloride on pH microclimate and electrogenic Na+ absorption across the rumen epithelium of goat and sheep

2006 ◽  
Vol 291 (2) ◽  
pp. G246-G252 ◽  
Author(s):  
S. Leonhard-Marek ◽  
G. Breves ◽  
R. Busche
Keyword(s):  
Apical Membrane ◽  
Short Circuit ◽  
Basolateral Membrane ◽  
Short Circuit Current ◽  
Epithelial Surface ◽  
Ussing Chambers ◽  
Rumen Epithelium ◽  
Microclimate Ph ◽  
Cation Conductance ◽  
Sheep Rumen

Active Na+ absorption across rumen epithelium comprises Na+/H+ exchange and a nonselective cation conductance (NSCC). Luminal chloride is able to stimulate Na+ absorption, which has been attributed to an interaction between Cl−/HCO3− and Na+/H+ exchangers. However, isolated rumen epithelial cells also express a Cl− conductance. We investigated whether Cl− has an additional effect on electrogenic Na+ absorption via NSCC. NSCC was estimated from short-circuit current ( Isc) across epithelia of goat and sheep rumen in Ussing chambers. Epithelial surface pH (pHs) was measured with 5- N-hexadecanoyl-aminofluorescence. Membrane potentials were measured with microelelectrodes. Luminal, but not serosal, Cl− stimulated the Ca2+ and Mg2+ sensitive Isc. This effect was independent of the replacing anion (gluconate or acetate) and of the presence of bicarbonate. The mean pHs of rumen epithelium amounted to 7.47 ± 0.03 in a low-Cl− solution. It was increased by 0.21 pH units when luminal Cl− was increased from 10 to 68 mM. Increasing mucosal pH from 7.5 to 8.0 also increased the Ca2+ and Mg2+ sensitive Isc and transepithelial conductance and reduced the fractional resistance of the apical membrane. Luminal Cl− depolarized the apical membrane of rumen epithelium. 5-Nitro-2-(3-phenylpropylamino)-benzoate reduced the divalent cation sensitive Isc, but only in low-Cl− solutions. The results show that luminal Cl− can increase the microclimate pH via apical Cl−/HCO3− or Cl−/OH− exchangers. Electrogenic Na+ absorption via NSCC increases with pH, explaining part of the Cl− effects on Na+ absorption. The data further show that the Cl− conductance of rumen epithelium must be located at the basolateral membrane.

scholarly journals Performance Analysis of Mixed Natural Dye and Nanostructured Tio2 based DSSC

2020 ◽  
Vol 9 (7) ◽  
pp. 453-456
Keyword(s):  
Short Circuit ◽  
Electron Flow ◽  
Sol Gel ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Natural Dye ◽  
Nanostructured Tio2 ◽  
Beet Root ◽  
The Stability ◽  
The Individual

The performance of the mixed natural dye based DSSC has been evaluated in this paper. The mixture of beet root, spinach and turmeric are used with nanostructured TiO2 are used for the fabrication of DSSC. TiO2 is synthesized by sol-gel technique and considered as semiconductor metal oxide (SMO) to act as photo anode here. Nano wire type of morphology of TiO2 is found from the FESEM image which exhibits unidirectional and uniform electron flow. The XRD study reveals anatase and rutile phases of TiO2 that ensure the stability of synthesized TiO2 . The mixed dye made of beet root, spinach and turmeric shows their congruent characteristics with the broad light absorption spectra, lower diffused reflectance spectra after anchoring with SMO and better I-V characteristics in comparison with the individual one. The mixed dye-based DSSC provides the open-circuit voltage of 0.755V, short circuit current of 2.05mA, voltage and current at maximum power equal to 0.51V and 1.7mA, respectively with the efficiency of 0.867 %, in comparison to the efficiency of the individual dyes 0.305%, 0.266% and 0.473% with beet root, spinach and turmeric, respectively.

Functional and molecular biological evidence of SGLT-1 in the ruminal epithelium of sheep

2000 ◽  
Vol 279 (1) ◽  
pp. G20-G27 ◽  
Author(s):  
Jörg R. Aschenbach ◽  
Heike Wehning ◽  
Martina Kurze ◽  
Elisabeth Schaberg ◽  
Hermann Nieper ◽  
...  
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Short Chain Fatty Acids ◽  
Glucose Absorption ◽  
Minor Importance ◽  
Mrna Levels ◽  
Ussing Chambers ◽  
Ruminal Epithelium ◽  
Cloned Cdna ◽  
Mucosal Side

Because of the effective catabolism ofd-glucose to short-chain fatty acids by intraruminal microorganisms, the absorption of d-glucose from the rumen was thought to be of minor importance. However, clinical studies suggested that significant quantities of d-glucose are transported from the ruminal contents to the blood. We therefore tested the ruminal epithelium of sheep for the presence of Na+-glucose cotransporter 1 (SGLT-1) on both the functional and mRNA levels. In the absence of an electrochemical gradient, 3- O-methylglucose (3-OMG) was net absorbed across isolated ruminal epithelia mounted in Ussing chambers. The net transport of 3-OMG followed Michaelis-Menten kinetics and was sensitive to phlorizin or decreasing Na+concentrations. The mucosal addition of 10 mM d-glucose induced an immediate, phlorizin-sensitive increase in short-circuit current ( Isc). Isccould also be increased by serosal addition of d-glucose or d-mannose, but electrogenic uptake of d-glucose or 3-OMG added on the mucosal side was still detectable after serosal stimulation of Isc. RT-PCR using primers specific for the ovine intestinal SGLT-1 with subsequent TA cloning and sequencing revealed 100% identity between the cloned cDNA and mRNA fragment 187–621 of ovine intestinal SGLT-1. In conclusion, the ruminal epithelium has a high-affinity SGLT-1, which indicates that it maintains the capacity for d-glucose absorption.

scholarly journals The potential and short-circuit current across isolated rumen epithelium of the sheep

1966 ◽  
Vol 187 (3) ◽  
pp. 631-644 ◽  
Author(s):  
H. G. Ferreira ◽  
F. A. Harrison ◽  
R. D. Keynes
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Rumen Epithelium

scholarly journals Thiamine Alleviates High-Concentrate-Diet-Induced Oxidative Stress, Apoptosis, and Protects the Rumen Epithelial Barrier Function in Goats

2021 ◽  
Vol 8 ◽  
Author(s):  
Yi Ma ◽  
Ying Zhang ◽  
Hao Zhang ◽  
Hongrong Wang
Keyword(s):  
Superoxide Dismutase ◽  
Tumor Necrosis Factor ◽  
Barrier Function ◽  
Tumor Necrosis ◽  
Epithelial Barrier ◽  
Nuclear Factor ◽  
Epithelial Barrier Function ◽  
Rumen Epithelium ◽  
Ruminal Epithelium ◽  
Necrosis Factor

High-concentrate diets are continually used in ruminants to meet the needs of milk yield, which can lead to the occurrence of subacute rumen acidosis in ruminants. This study investigated the protective effects of dietary thiamine supplementation on the damage of the ruminal epithelium barrier function in goats fed a high-concentrate diet. Twenty-four healthy Boer goats (live weight of 35.62 ± 2.4 kg; age, 1 year) were randomly assigned into three treatments, with eight goats in each treatment, consuming one of three diets: a low-concentrate diet (CON; concentrate/forage, 30:70), a high-concentrate diet (HC; concentrate/forage, 70:30), or a high-concentrate diet with 200 mg of thiamine/kg of dry matter intake (HCT; concentrate/forage, 70:30) for 12 weeks. The additional dose of thiamine was based on our previous study wherein thiamine ameliorates inflammation. Compared with HC treatment, the HCT treatment had markedly higher concentrations of glutathione, superoxide dismutase, and glutathione peroxidase and total antioxidant capacity (P &lt; 0.05) in plasma and rumen epithelium. The results showed that the apoptosis index was lower (P &lt; 0.05) in the HCT treatment than in that of the HC treatment. Compared with the HC treatment, permeability and the electrophysiology parameter short circuit current for ruminal epithelial tissue were significantly decreased (P &lt; 0.05) in the HCT treatment. The immunohistochemical results showed that the expression distribution of tight junctions including claudin-1, claudin-4, occludin, and zonula occludin-1 (ZO-1) was greater (P &lt; 0.05) in the HCT treatments than in the HC treatment. The mRNA expression in the rumen epithelium of ZO-1, occludin, claudin-1, B-cell lymphoma/leukemia 2, nuclear factor erythroid-2 related factor 2 (Nrf2), superoxide dismutase 2 (SOD2), glutathione peroxidase 1, and the phase II metabolizing enzymes quinone oxidoreductase and heme oxygenase in the HCT group was significantly increased in comparison with the HC diet treatment (P &lt; 0.05), whereas the mRNA expression of caspase 3, caspase 8, caspase 9, bcl-2 associated X protein, lipopolysaccharide binding protein, toll-like receptor 4, nuclear factor kappa-B (NFκB), tumor necrosis factor alpha, interleukin-1β, interleukin, and tumor necrosis factor receptor-associated factor 6 decreased significantly in the HCT treatment (P &lt; 0.05). Compared with the HC treatment, the HCT diet significantly increased the protein expression of ZO-1, occludin, claudin-1, NQO1, HO-1, SOD2, serine/threonine kinase, p-Akt, Nrf2, and p-Nrf2; conversely, the expression of NFκB-related proteins p65 and pp65 was significantly decreased (P &lt; 0.05). In addition, thiamine relieved the damage on the ruminal epithelium caused by the HC diet. The results show that dietary thiamine supplementation improves the rumen epithelial barrier function by regulating Nrf2–NFκB signaling pathways during high-concentrate-diet feeding.

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