Endotoxin-induced ileal mucosal hyperpermeability in pigs: role of tissue acidosis

1994 ◽  
Vol 266 (4) ◽  
pp. G633-G646 ◽  
Author(s):  
A. L. Salzman ◽  
H. Wang ◽  
P. S. Wollert ◽  
T. J. Vandermeer ◽  
C. C. Compton ◽  
...  
Keyword(s):  
Fluorescein Isothiocyanate ◽  
Mucosal Permeability ◽  
Doppler Flowmetry ◽  
Tissue Ischemia ◽  
Mucosal Perfusion ◽  
Series Of Experiments ◽  
Tissue Acidosis ◽  
Fluorescein Isothiocyanate Dextran ◽  
Hypoxic Group

Administration of lipopolysaccharide (LPS) to experimental animals leads to diminished mesenteric perfusion, increased ileal mucosal [H+] , and increased gut epithelial permeability to hydrophilic solutes. We sought to determine whether these phenomena are causally related. Experiments were performed in anesthetized pigs. Permeability was assessed by measuring the plasma-to-lumen clearance of fluorescein isothiocyanate dextran (4,000 Da; FD-4) by a segment of ileum perfused with Ringer lactate solution. Mucosal perfusion (Qmuc) and [H4+] were estimated using laser-Doppler flowmetry and tonometry, respectively. In an initial series of experiments, we showed that mucosal permeability was linearly correlated with mucosal [H+] in animals subjected to graded degrees of mechanically induced mesenteric ischemia (n = 14, R2 = 0.58, P < 0.002) or injected with graded doses of LPS (n = 11, R2 = 0.93, P < 0.0001). In a second series of experiments, we induced mucosal acidosis in normal pigs by mechanical ventilation with either a hypoxic (n = 7) or a hypercapnic (n = 5) gas mixture. In both groups, ileal mucosal permeability to FD-4 increased significantly (P < 0.05), although transmesenteric release of lactate increased significantly only in the hypoxic group. Qmuc was unchanged in both groups. These data suggest that mucosal acidosis, even in the absence of tissue ischemia or hypoxia, increases intestinal permeability to a macromolecular hydrophilic solute. Tissue acidosis may be an important factor contributing to LPS-induced gut mucosal hyperpermeability.

scholarly journals Intestinal permeability is reduced and IL-10 levels are increased in septic IL-6 knockout mice

2001 ◽  
Vol 281 (3) ◽  
pp. R1013-R1023 ◽  
Author(s):  
Quan Wang ◽  
Cheng Hui Fang ◽  
Per-Olof Hasselgren
Keyword(s):  
Intestinal Permeability ◽  
Cecal Ligation ◽  
Fluorescein Isothiocyanate ◽  
Sham Operation ◽  
Cecal Ligation And Puncture ◽  
Wild Type ◽  
Mucosal Permeability ◽  
Ussing Chambers ◽  
Intestinal Segments

Sepsis is associated with increased intestinal permeability, but mediators and mechanisms are not fully understood. We examined the role of interleukin (IL)-6 and IL-10 in sepsis-induced increase in intestinal permeability. Intestinal permeability was measured in IL-6 knockout (IL-6 −/−) and wild-type (IL-6 +/+) mice 16 h after induction of sepsis by cecal ligation and puncture or sham operation. In other experiments, mice or intestinal segments incubated in Ussing chambers were treated with IL-6 or IL-10. Intestinal permeability was assessed by determining the transmucosal transport of the 4.4-kDa marker fluorescein isothiocyanate conjugated dextran and the 40-kDa horseradish peroxidase. Intestinal permeability for both markers was increased in septic IL-6 +/+ mice but not in septic IL-6 −/− mice. Treatment of nonseptic mice or of intestinal segments in Ussing chambers with IL-6 did not influence intestinal permeability. Plasma IL-10 levels were increased in septic IL-6 −/− mice, and treatment of septic mice with IL-10 resulted in reduced intestinal permeability. Increased intestinal permeability during sepsis may be regulated by an interaction between IL-6 and IL-10. Treatment with IL-10 may prevent the increase in mucosal permeability during sepsis.

Effect of urethan anesthesia on cigarette smoke-induced airway injury in guinea pigs

1987 ◽  
Vol 63 (1) ◽  
pp. 84-91 ◽  
Author(s):  
A. R. Burns ◽  
J. Van Oostdam ◽  
D. C. Walker ◽  
J. C. Hogg
Keyword(s):  
Guinea Pig ◽  
Cigarette Smoke ◽  
Airway Resistance ◽  
Fluorescein Isothiocyanate ◽  
Airway Responsiveness ◽  
Smoke Exposure ◽  
Airway Reactivity ◽  
Mucosal Permeability ◽  
Airway Injury ◽  
Fluorescein Isothiocyanate Dextran

The effect of urethan anesthesia on cigarette smoke-induced airway responsiveness and permeability was studied in the guinea pig. Airway responsiveness was determined by measuring changes to airway resistance to graded doses of aerosolized histamine, and mucosal permeability was determined by measuring the appearance of fluorescein isothiocyanate-dextran (FITC-D) in the blood and examining its distribution in lung tissue after it had been delivered to the lung in an aerosol. The results confirm previous studies that smoke exposure increased airway responsiveness and mucosal permeability. They also show that urethan anesthesia administered before smoke exposure prevented the smoke-related changes in airway reactivity and mucosal permeability. In animals that remained conscious during the smoke exposure, there was increased deposition of the dextran in the regions of the bronchioloalveolar junctions with a more rapid uptake of FITC-D into the blood. We postulate that, when urethan anesthesia is administered before smoke exposure, the exudative phase of the inflammatory reaction produced by smoke exposure is suppressed.

LRRC19 Promotes Permeability of the Gut Epithelial Barrier Through Degrading PKC-ζ and PKCι/λ to Reduce Expression of ZO1, ZO3, and Occludin

2021 ◽  
Author(s):  
Xiaomin Su ◽  
Jianmei Wei ◽  
Houbao Qi ◽  
Mengli Jin ◽  
Qianjing Zhang ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Fluorescein Isothiocyanate ◽  
Clinical Samples ◽  
Epithelial Barrier ◽  
Gut Barrier Function ◽  
Transmission Electron ◽  
Fluorescein Isothiocyanate Dextran ◽  
Pkc Ζ ◽  
Epithelium Cells

Abstract Background A dysfunctional gut epithelial barrier allows the augmented permeation of endotoxins, luminal antigens, and bacteria into the bloodstream, causing disease. The maintenance of gut epithelial barrier integrity may be regulated by multiple factors. Herein we analyze the role of leucine-rich repeat-containing protein 19 (LRRC19) in regulating the permeability of the gut epithelial barrier. Methods We utilized Lrrc19 knockout (KO) mice and clinical samples through transmission electron, intestinal permeability assay, Western blot, and immunofluorescence staining to characterize the role of LRRC19 in the permeability of the gut epithelial barrier. Results We found that LRRC19, which is expressed in gut epithelial cells, impairs gut barrier function. Transmission electron micrographs revealed a tighter junction and narrower gaps in the colon epithelium cells in LRRC19 KO mice. There were lower levels of serum lipopolysaccharide and 4 kDa-fluorescein isothiocyanate-dextran after gavage in LRRC19 KO mice than in wild-type mice. We found that LRRC19 could reduce the expression of zonula occludens (ZO)-1, ZO-3, and occludin in the colonic epithelial cells. The decreased expression of ZO-1, ZO-3, and occludin was dependent on degrading protein kinase C (PKC) ζ and PKCι/λ through K48 ubiquitination by LRRC19. The expression of LRRC19 was also negatively correlated with ZO-1, ZO-3, occludin, PKCζ, and PKCι/λ in human colorectal cancers. Conclusions The protein LRRC19 can promote the permeability of the gut epithelial barrier through degrading PKC ζ and PKCι/λ to reduce the expression of ZO-1, ZO-3, and occludin.

Effects of Short-term Fenoldopam Infusion on Gastric Mucosal Blood Flow in Septic Shock

2004 ◽  
Vol 101 (3) ◽  
pp. 576-582 ◽  
Author(s):  
Andrea Morelli ◽  
Monica Rocco ◽  
Giorgio Conti ◽  
Alessandra Orecchioni ◽  
Andrea De Gaetano ◽  
...  
Keyword(s):  
Septic Shock ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Laser Doppler ◽  
Mucosal Barrier ◽  
Short Term ◽  
Mucosal Permeability ◽  
Doppler Flowmetry ◽  
Mucosal Perfusion ◽  
Gastric Mucosal Perfusion

Background Inadequate splanchnic perfusion in septic shock is associated with increased morbidity and mortality. As result of splanchnic ischemia, mucosal permeability increases. Considering the implication of improved mucosal perfusion in terms of maintenance of mucosal barrier integrity, dopamine-1 receptor stimulation could be helpful in septic shock. The goal of the current study was to determine the effects of fenoldopam on systemic hemodynamic parameters and gastric mucosal perfusion in patients with septic shock. Furthermore, the authors tested the hypothesis that the addition of fenoldopam (0.1 microg x kg(-1) x min(-1)) to a combination of norepinephrine and dobutamine (5 microg x kg(-1) x min(-1)) may improve gastric mucosal perfusion in septic shock. Methods Patients with septic shock were randomized to a double-blind 2-h infusion of fenoldopam (n = 20) or placebo (n = 20). Each group received dobutamine (5 microg x kg(-1) x min(-1)), and the dosage of norepinephrine was adjusted to achieve a mean arterial pressure between 70 and 80 mmHg. A laser-Doppler probe and tonometer were introduced into the gastric lumen. Results A significant increase in gastric mucosal perfusion, detected by laser-Doppler flowmetry, was observed in the group treated with fenoldopam (P &lt; 0.05). In addition, this increase in microcirculatory flow occurred despite the fact that systemic flow remained unchanged. Differences in gastroarterial partial pressure of carbon dioxide values were not statistically significant in the fenoldopam and placebo groups. Conclusions The study showed that, for the same mean arterial pressure, short-term fenoldopam infusion increased gastric mucosal perfusion in patients with septic shock.

Platelet-activating factor-induced mucosal dysfunction: role of oxidants and granulocytes

1991 ◽  
Vol 260 (6) ◽  
pp. G965-G971 ◽  
Author(s):  
P. Kubes ◽  
K. E. Arfors ◽  
D. N. Granger
Keyword(s):  
Platelet Activating Factor ◽  
Fold Increase ◽  
Iron Chelator ◽  
Phagocytic Cells ◽  
Fluid Flux ◽  
Mucosal Permeability ◽  
51Cr Edta ◽  
Series Of Experiments ◽  
Higher Doses

We tested the possibility that platelet-activating factor (PAF) exerts some of its actions on the microvascular and mucosal membranes by stimulating the production of reactive O2 metabolites. Two series of experiments were performed using autoperfused segments of cat ileum pretreated with human recombinant superoxide dismutase (hSOD), catalase (H2O2 scavenger), or deferoxamine (an iron chelator). In the first series, we examined the effects of PAF infusion on mucosal permeability (blood-to-lumen clearance) to 51Cr-EDTA. PAF induced a 4-, 25-, and 20-fold increase in 51Cr-EDTA clearance at 4, 20, and 40 ng/min, respectively, and the increase was positively correlated with luminal fluid flux. hSOD, catalase, and deferoxamine reduced the 51Cr-EDTA clearance at each PAF dose and eliminated the dependence of 51Cr-EDTA clearance on transmucosal fluid flux. To determine whether mucosal granulocytes were the source of the reactive O2 metabolites, the mucosa was depleted of myeloperoxidase-positive cells using an antibody against the leukocyte integrin CD11/CD18. Mucosal granulocyte depletion resulted in a greatly reduced clearance of 51Cr-EDTA, suggesting that resident granulocytes may be the source of the reactive O2 metabolites. In a second series of studies, we examined the influence of hSOD, catalase, and deferoxamine on the increased transcapillary fluid and protein fluxes induced by intra-arterial PAF infusion. These agents attenuated the enhanced transvascular fluid and protein filtration by greater than 50% at the low dose but had no effect at the higher doses. We conclude that the PAF-induced increase in mucosal permeability to 51Cr-EDTA is mediated by reactive O2 metabolites produced by resident phagocytic cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Physiological Effects of Nonimmune Platelet Associated Immunoglobulin G

1981 ◽  
Vol 45 (01) ◽  
pp. 027-033 ◽  
Author(s):  
K Sugiura ◽  
M Steiner ◽  
M Baldini
Keyword(s):  
Shape Change ◽  
Fluorescein Isothiocyanate ◽  
Recovery Phase ◽  
Human Platelets ◽  
Serotonin Release ◽  
Platelet Volume ◽  
Igg Antibody ◽  
Heterologous Antiserum ◽  
Igg Binding ◽  
Series Of Experiments

SummaryThe function of nonimmune IgG associated with platelets is unknown. In a series of experiments we have investigated this problem, relating amount of platelet-associated IgG (PAIgG) to platelet volume, serotonin release, adherence of platelets to monocytes and platelet senescence. Most of these studies were performed with human platelets. Platelets freed of preexisting PAIgG by incubation at 22° C were incubated with IgG in a series of concentrations ranging from 0.4 — 27.0 X10-6 M. The IgG preparations used were demonstrably free of aggregated forms of the protein. The amount of PAIgG bound to platelets was determined by the use of fluorescein isothiocyanate-conjugated anti-IgG antibody (F-anti-IgG antibody) which was quantified in a fluorospectrophotometer. Newly bound IgG was assayed similarly by the use of F-IgG. A dose-dependent increase in platelet volume was associated with the binding of nonimmune IgG by platelets. The process which leveled off at an IgG concentration of 1.2 —1.5 X10-5 M was almost fully reversible and was not due to platelet shape change or aggregation. Release of serotonin from IgG-treated platelets was relatively small but to the extent that it occurred was positively related to the IgG concentration to which platelets were exposed. Adherence to autologous monocytes studied quantitatively by the use of formaldehyde-fixed cells was also positively related to the amount of IgG on the platelets. Normal or IgG-defident serum had a potent inhibitory (noncompetitive) action on the binding of F-IgG and F-anti-human IgG antibody to human platelets. Cohorts of platelets prepared in rabbits during the recovery phase of immunological thrombocytopenia induced by injection of heterologous antiserum, showed an age-dependent increase of PAIgG and of IgG binding. These results suggest that PAIgG plays a role in the clearance of senescent platelets.

scholarly journals Spray-Dried Plasma Improves Body Weight, Intestinal Barrier Function, and Tibia Strength during Experimental Constant Heat Stress Conditions

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2213
Author(s):  
Jared Ruff ◽  
Thaina L. Barros ◽  
Joy Campbell ◽  
Ricardo González-Esquerra ◽  
Christine N. Vuong ◽  
...  
Keyword(s):  
Heat Stress ◽  
Intestinal Barrier ◽  
Fluorescein Isothiocyanate ◽  
Serum Levels ◽  
Negative Control ◽  
Intestinal Barrier Function ◽  
Negative Consequences ◽  
Fluorescein Isothiocyanate Dextran ◽  
Prolonged Heat ◽  
Spray Dried

The aim of this study was to see how spray-dried plasma (SDP) supplementation affected broiler chicken performance, intestinal permeability, and bone strength during persistent heat stress. One-day-old chicks (n = 480) were randomly assigned into twelve environmental corrals; four thermoneutral (TN-negative control, maintained at 24 °C from d 21–42); four heat stress (HS, exposed to 35 °C from d 21–42); and four heat stress treated with 2% SDP in the feed until d 28 followed by 1% SDP until d 42 (HS-SDP). The performance and serum levels of fluorescein isothiocyanate-dextran (FITC-d) were evaluated at d 21, 28, 35, and 42. The tibias strength was evaluated on d 21 and 42. The increment in chicken temperature (p < 0.05) was observed two h following the increase in environmental temperature in both HS groups and was associated with decreased performance parameters compared with the TN group. At d 42 of age, the chickens exposed to HS had an impaired gut permeability and decreased tibia strength compared to the TN group (p < 0.05). However, partially feeding SDP mitigated these adverse effects significantly. These findings imply that using SDP strategically during stressful times, such as prolonged heat stress, may help mitigate its negative consequences.

scholarly journals Delivery of Foreign Materials into Adherent Cells by Gold Nanoparticle-Mediated Photoporation

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 550
Author(s):  
Xiaofan Du ◽  
Jing Wang ◽  
Lan Chen ◽  
Zhenxi Zhang ◽  
Cuiping Yao
Keyword(s):  
Fluorescein Isothiocyanate ◽  
Adherent Cells ◽  
Thermal Dynamics ◽  
Cervical Cell ◽  
Nanosecond Pulse Laser ◽  
Fluorescein Isothiocyanate Dextran ◽  
Extracellular Materials ◽  
Foreign Materials ◽  
Cell Medium ◽  
Delivery Efficiency

Delivering extracellular materials into adherent cells presents several challenges. A homemade photoporation platform, mediated by gold nanoparticles (AuNPs), was constructed to find a suitable method for finding all adherent cells in this process with high delivery efficiency. The thermal dynamics of AuNPs could be monitored. Based on this system, 60 nm AuNPs were selected to be attached to cells for optimal photoporation. After irradiating the cells covered with AuNPs using a nanosecond pulse laser, fluorescein isothiocyanate-dextran in the medium were delivered into optoporated adherent HeLa (human cervical cell lines) cells. The delivery efficiency and cell viability of this process were evaluated using a fluorescence microscope and flow cytometry. The experimental results showed that targeting cells using antibodies, laser irradiation from the top of the cell culture well, and reducing the cell medium are important for improving the delivery efficiency. The optimal loading efficiency for adherent HeLa cells was 53.4%.

Nitric oxide decreases lung liquid production via guanosine 3′,5′-cyclic monophosphate

2001 ◽  
Vol 280 (5) ◽  
pp. L923-L929 ◽  
Author(s):  
James J. Cummings ◽  
Huamei Wang
Keyword(s):  
Nitric Oxide ◽  
Pulmonary Epithelium ◽  
Fetal Sheep ◽  
Cgmp Analog ◽  
Pulmonary Arterial ◽  
Series Of Experiments ◽  
Lung Liquid ◽  
Tracer Dilution ◽  
Induced Changes

We studied the role of cGMP in nitric oxide (NO)-induced changes in lung liquid production ( J v ) in chronically instrumented fetal sheep. Forty-five studies were done in which J v was measured by a tracer dilution technique. Left pulmonary arterial flow (Qlpa) was measured by a Doppler flow probe. There were two series of experiments. In the first, we gave 8-bromo-cGMP, a cGMP analog, by either the pulmonary vascular or intraluminal route; in the second, we used agents to inhibit or enhance endogenous cGMP activity. When infused directly into the pulmonary circulation, 8-bromo-cGMP significantly increased Qlpa but had no effect on J v. Conversely, when instilled into the lung liquid, 8-bromo-cGMP had no effect on Qlpa but significantly reduced J v. Inhibition of guanylate cyclase activity with methylene blue totally blocked, whereas phosphodiesterase inhibition with Zaprinast significantly enhanced, the effect of instilled NO on J v. Thus the reduction in lung liquid caused by NO appears to be mediated by cGMP, perhaps through a direct effect on the pulmonary epithelium.

Sign in / Sign up

Export Citation Format

Share Document