scholarly journals Effect of ruminal acidosis and short-term low feed intake on indicators of gastrointestinal barrier function in Holstein steers

2018 ◽  
Vol 96 (1) ◽  
pp. 108-125 ◽  
Author(s):  
Rae-Leigh A Pederzolli ◽  
Andrew G Van Kessel ◽  
John Campbell ◽  
Steve Hendrick ◽  
Katie M Wood ◽  
...  
Keyword(s):  
Barrier Function ◽  
Distal Colon ◽  
Proximal Colon ◽  
Cell Junction ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Ruminal Acidosis ◽  
Junction Protein ◽  
Ad Libitum ◽  
Ad Libitum Intake

Abstract The objective of this study was to determine effect of ruminal acidosis (RA) and low feed intake [LFI] on the regional barrier function of the gastrointestinal tract. Twenty-one Holstein steers were fed for ad libitum intake for 5 d (control [CON]), fed at 25% of ad libitum intake for 5 d (LFI), or provided 2 d of ad libitum intake followed by 1-d of feed restriction (25% of ad libitum intake), 1 d where 30% of ad libitum dry matter intake (DMI) was provided as pelleted barley followed by the full allocation (RA) and fed for ad libitum intake the following day. Tissues and digesta from the rumen, omasum, duodenum, jejunum, ileum, cecum, proximal, and distal colon were collected. Permeability was assessed using the mucosal-to-serosal flux of inulin (JMS-inulin) and mannitol (JMS-mannitol). Digesta pH was 0.81, 0.63, and 0.42 pH units less for RA than CON in the rumen, cecum, and proximal colon; while, LFI had pH that was 0.47 and 0.36 pH units greater in the rumen and proximal colon compared to CON. Total ruminal short-chain fatty acid (SCFA) concentration were less for LFI (92 mM; P = 0.010) and RA (87 mM; P = 0.007) than CON (172 mM) steers. In the proximal colon, the proportion of butyrate (P = 0.025 and P = 0.022) and isobutyrate (P = 0.019 and P = 0.019) were greater, and acetate (P = 0.028 and P = 0.028) was less for LFI and RA, respectively, when compared to CON steers. Ruminal papillae length, width, perimeter, and surface area were 1.21 mm, 0.78 mm, 3.84 mm, and 11.15 mm2 less for LFI than CON; while, RA decreased papillae width by 0.52 mm relative to CON. The JMS-mannitol was less for LFI steers than CON in the proximal colon (P = 0.041) and in the distal colon (P = 0.015). Increased gene expression for claudin 1, occludin, tight-cell junction protein 1 and 2, and toll-like receptor 4 were detected for LFI relative to CON in the rumen, jejunum, and proximal colon. For RA steers, expression of toll-like receptor 4 in the rumen, and occludin and tight-cell junction protein 1 were greater in the jejunum than CON. An acute RA challenge decreased pH in the rumen and large intestine but did not increase tissue permeability due to increases in the expression of genes related to barrier function within 1 d of the challenge. Steers exposed to LFI for 5 d had reduced ruminal SCFA concentrations, smaller ruminal papillae dimensions, and increased tissue permeability in the proximal and distal colon despite increases for genes related to barrier function and immune function.

Effect of monensin on meal frequency during sub-acute ruminal acidosis in dairy cows

2005 ◽  
Vol 85 (2) ◽  
pp. 247-249 ◽  
Author(s):  
D. E. Lunn ◽  
T. Mutsvangwa ◽  
N. E. Odongo ◽  
T. F. Duffield ◽  
R. Bagg ◽  
...  
Keyword(s):  
Controlled Release ◽  
Dairy Cows ◽  
Key Words ◽  
Recovery Period ◽  
Meal Frequency ◽  
Total Mixed Ration ◽  
Ruminal Acidosis ◽  
Lactating Dairy Cows ◽  
Ad Libitum ◽  
Ad Libitum Intake

Two experiments were conducted to determine the effects of monensin (Rumensin® controlled-release capsule; exp. 1 and Rumensin® Premix; exp. 2) on meal frequency during grain-induced sub-acute ruminal acidosis (SARA) in Holstein dairy cows. SARA was induced by restricting total mixed ration intake to 85% of ad libitum intake and replacing the remaining 15% with a grain pellet consisting of 50% wheat and 50% barley. In both experiments, meal frequency during SARA was lower (P < 0.05) than meal frequency during the adaptation and recovery periods. In exp. 2, monensin increased meal frequency during SARA (6.0 vs. 7.2, P = 0.04) and meal frequency during the recovery period (7.5 vs. 9.0, P = 0.004). These results suggest monensin premix may increase meal frequency in lactating dairy cows under conditions of SARA. Key words: dairy cows, monensin, ruminal acidosis, meal frequency

scholarly journals Ruminal Lipopolysaccharides Analysis: Uncharted Waters with Promising Signs

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 195
Author(s):  
Efstathios Sarmikasoglou ◽  
Antonio P. Faciola
Keyword(s):  
Escherichia Coli ◽  
Lipid A ◽  
Epithelial Tissue ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Subacute Ruminal Acidosis ◽  
Gram Negative ◽  
Outer Membranes ◽  
Ruminal Acidosis ◽  
Analysis Protocol

The objective of this review is to present the need for the development of a comprehensive ruminal lipopolysaccharide (LPS) extraction, purification and analysis protocol and state hypotheses that could contribute to planning novel strategies against ruminal acidosis. Lipopolysaccharide is an immunostimulatory molecule of Gram-negative bacterial outer membranes and has been reported to contribute to ruminal acidosis in cattle. Bacterial death and lysis are normal processes, and thus LPS is normally present in ruminal fluid. However, ruminal LPS concentration is much greater during subacute ruminal acidosis (SARA). Contrary to the widely known LPSs, ruminal LPS seems to be composed of a variety of LPS chemotypes that may interact with each other resulting in an LPS “mixture”. Hypotheses regarding the influence of each specific ruminal bacterial specie to innate immunity during SARA, and the representativeness of the exclusive use of the Escherichia coli LPS to rumen epithelial tissue challenges, could expand our knowledge regarding SARA. In addition, possible correlation between the monomeric Toll-like Receptor 4 (TRL4) and the antagonistic penta-acylated lipid A of LPS could contribute to novel strategies to tackle this nutrition disorder.

scholarly journals Symbiotic Bacterial Metabolites Regulate Gastrointestinal Barrier Function via the Xenobiotic Sensor PXR and Toll-like Receptor 4

Immunity ◽  
2014 ◽  
Vol 41 (2) ◽  
pp. 296-310 ◽  
Author(s):  
Madhukumar Venkatesh ◽  
Subhajit Mukherjee ◽  
Hongwei Wang ◽  
Hao Li ◽  
Katherine Sun ◽  
...  
Keyword(s):  
Barrier Function ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Bacterial Metabolites ◽  
Gastrointestinal Barrier

scholarly journals Cx43 and the Actin Cytoskeleton: Novel Roles and Implications for Cell-Cell Junction-Based Barrier Function Regulation

Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1656
Author(s):  
Randy E. Strauss ◽  
Robert G. Gourdie
Keyword(s):  
Actin Cytoskeleton ◽  
Focal Adhesion ◽  
Barrier Function ◽  
Molecular Structures ◽  
Cell Junction ◽  
Therapeutic Outcomes ◽  
Junction Protein ◽  
Wide Range ◽  
Channel Dependent ◽  
Tissue Compartments

Barrier function is a vital homeostatic mechanism employed by epithelial and endothelial tissue. Diseases across a wide range of tissue types involve dynamic changes in transcellular junctional complexes and the actin cytoskeleton in the regulation of substance exchange across tissue compartments. In this review, we focus on the contribution of the gap junction protein, Cx43, to the biophysical and biochemical regulation of barrier function. First, we introduce the structure and canonical channel-dependent functions of Cx43. Second, we define barrier function and examine the key molecular structures fundamental to its regulation. Third, we survey the literature on the channel-dependent roles of connexins in barrier function, with an emphasis on the role of Cx43 and the actin cytoskeleton. Lastly, we discuss findings on the channel-independent roles of Cx43 in its associations with the actin cytoskeleton and focal adhesion structures highlighted by PI3K signaling, in the potential modulation of cellular barriers. Mounting evidence of crosstalk between connexins, the cytoskeleton, focal adhesion complexes, and junctional structures has led to a growing appreciation of how barrier-modulating mechanisms may work together to effect solute and cellular flux across tissue boundaries. This new understanding could translate into improved therapeutic outcomes in the treatment of barrier-associated diseases.

scholarly journals EphrinB2-EphB4 signalling provides Rho-mediated homeostatic control of lymphatic endothelial cell junction integrity

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Maike Frye ◽  
Simon Stritt ◽  
Henrik Ortsäter ◽  
Magda Hernandez Vasquez ◽  
Mika Kaakinen ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Barrier Function ◽  
Lymphatic Vessel ◽  
Lymphatic Vessels ◽  
Lymphatic Endothelial Cell ◽  
Cell Junction ◽  
Adult Mice ◽  
Junction Protein ◽  
Vessel Integrity ◽  
And Function

Endothelial integrity is vital for homeostasis and adjusted to tissue demands. Although fluid uptake by lymphatic capillaries is a critical attribute of the lymphatic vasculature, the barrier function of collecting lymphatic vessels is also important by ensuring efficient fluid drainage as well as lymph node delivery of antigens and immune cells. Here, we identified the transmembrane ligand EphrinB2 and its receptor EphB4 as critical homeostatic regulators of collecting lymphatic vessel integrity. Conditional gene deletion in mice revealed that EphrinB2/EphB4 signalling is dispensable for blood endothelial barrier function, but required for stabilization of lymphatic endothelial cell (LEC) junctions in different organs of juvenile and adult mice. Studies in primary human LECs further showed that basal EphrinB2/EphB4 signalling controls junctional localisation of the tight junction protein CLDN5 and junction stability via Rac1/Rho-mediated regulation of cytoskeletal contractility. EphrinB2/EphB4 signalling therefore provides a potential therapeutic target to selectively modulate lymphatic vessel permeability and function.

Characterising barrier function among regions of the gastrointestinal tract in Holstein steers

2014 ◽  
Vol 54 (9) ◽  
pp. 1282 ◽  
Author(s):  
G. B. Penner ◽  
J. R. Aschenbach ◽  
K. Wood ◽  
M. E. Walpole ◽  
R. Kanafany-Guzman ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Barrier Function ◽  
Short Circuit ◽  
Ussing Chamber ◽  
Distal Colon ◽  
Proximal Colon ◽  
Flux Rate ◽  
Buffer Solution ◽  
Solution Ph ◽  
Mannitol Flux

The objective of this study was to characterise the regional variation in the barrier function of the gastrointestinal tract in Holstein calves using the flux rates of mannitol and inulin as permeability markers and tissue conductance (Gt) as an electrophysiological indicator of barrier function. Six Holstein steer calves (6 months of age) fed a common diet were used. Calves were killed by captive bolt stunning and pithing, and tissues were collected from the rumen, omasum, duodenum, jejunum, ileum, caecum, proximal colon, and distal colon. Tissues were carefully washed using a pre-heated (38.5°C) buffer solution (pH 7.4) saturated with oxygen and then transported to the laboratory. The mucosa was prepared by hand stripping and mounted between two halves of an Ussing chamber (n = 3/region with an exposed surface area of 3.14 cm2 for rumen and omasum and 1 cm2 for all other tissues). All tissues were incubated under short-circuit conditions and exposed to a similar buffer solution except for the energy source; rumen, omasum, caecum, and colon tissues were incubated with buffer containing short-chain fatty acids while tissues from the small intestine were bathed in buffer containing glucose. The Gt and the serosal-to-mucosal flux rates of 14C-inulin and 3H-mannitol were measured as indicators of barrier function. The serosal-to-mucosal flux rate of mannitol was greatest (P < 0.001) in the jejunum [104.8 nmol/(cm2 × h)] and least in the rumen and omasum [20.3 and 18.6 nmol/(cm2 × h), respectively]. In contrast, the serosal-to-mucosal flux rate of inulin was greatest (P < 0.001) in the omasum [158.6 nmol/(cm2 × h)] followed by the rumen [87.3 nmol/(cm2 × h)] with no differences among the other regions [18.7 – 62.0 nmol/(cm2 × h)]. The Gt was greatest (P < 0.001) in the jejunum (34.6 mS/cm2) and least for the rumen (3.67 mS/cm2) and omasum (3.23 mS/cm2). The Gt was correlated with both inulin and mannitol flux rates in duodenum, caecum and proximal colon (P < 0.05); whereas, no such correlations existed in jejunum, ileum and distal colon. The Gt was correlated with the mannitol flux rate but not the inulin flux rate in rumen and omasum. For all regions but the rumen and omasum there was a positive correlation between mannitol and inulin flux rates. These data indicate that the translocation of a large molecule (inulin) across the omasum and rumen is greatest despite having an apparently tight epithelium based on Gt and mannitol flux rate, while the jejunum appears to have greatest potential for paracellular permeability.

Sign in / Sign up

Export Citation Format

Share Document