Involvement of capsaicin-sensitive primary afferent fibers in regulation of jejunal alanine absorption

1995 ◽  
Vol 268 (4) ◽  
pp. G695-G699 ◽  
Author(s):  
C. F. Nassar ◽  
K. A. Barada ◽  
L. E. Abdallah ◽  
W. S. Hamdan ◽  
A. M. Taha ◽  
...  
Keyword(s):  
Inhibitory Effect ◽  
Dependent Manner ◽  
Primary Afferent ◽  
In Vivo Experiments ◽  
Afferent Fibers ◽  
Cervical Vagotomy ◽  
Primary Afferent Fibers

Capsaicin-sensitive primary afferent fibers (CSPA) in the small intestine regulate many functions through the release of peptides and neurotransmitters. This study was undertaken to assess the role of CSPA in the regulation of jejunal alanine absorption in the rat. In a series of in vivo experiments, the effects of the sensory neurotoxin capsaicin on small intestinal alanine absorption were evaluated. In vitro experiments were also done to study its effects on alanine uptake by isolated jejunal strips and mucosal scrapings. Jejunal alanine absorption was reduced by 27% when capsaicin (160 and 800 microM) was perfused intraluminally and by 21% when it was applied topically to the cervical vagi. On the other hand, bilateral cervical vagotomy and reversible block of vagal CSPA increased alanine absorption by 29 and 41%, respectively. In vitro, capsaicin reduced alanine uptake by intestinal strips in a dose-dependent manner. Maximal inhibition (36.5%) occurred at 400 microM with the mean ineffective concentration at 87 microM. Alanine uptake by jejunal mucosal scrapings, however, was decreased only by 6.7% when incubated with 1,600 microM capsaicin. These data suggest that vagal CSPA exerts a tonic inhibitory effect on alanine absorption and that capsaicin's inhibitory effect on alanine absorption is mediated largely by the capsaicin-sensitive afferent fibers.

Acute and neonatal capsaicin treatment inhibit jejunal amino acid absorption through a Na+-dependent mechanism

1997 ◽  
Vol 272 (4) ◽  
pp. G815-G821 ◽  
Author(s):  
K. A. Barada ◽  
S. S. Dika ◽  
S. F. Atweh ◽  
N. E. Saade ◽  
C. F. Nassar
Keyword(s):  
Amino Acid ◽  
Intestinal Epithelial ◽  
Primary Afferent ◽  
Acid Absorption ◽  
Amino Acid Absorption ◽  
Afferent Fibers ◽  
Dependent Component ◽  
Primary Afferent Fibers

It has recently been shown that capsaicin inhibits alanine absorption in rat jejunum via mechanisms that involve intestinal capsaicin-sensitive primary afferent (CSPA) fibers. This study provides further evidence that the effect of capsaicin is neurally mediated and demonstrates that CSPA fibers regulate Na+-dependent amino acid absorption. In vivo, basal alanine absorption in rats neonatally treated with capsaicin was reduced by 35% below control. Furthermore, intraluminal perfusion of 400 microM capsaicin reduced jejunal alanine absorption by 31% in sham rats but had no significant effect in rats neonatally treated with capsaicin. In vitro, capsaicin significantly reduced uptake of alanine and proline by jejunal strips but had no effect on uptake of lysine. Tetrodotoxin (0.2 microM) partially blocked the effects of capsaicin but did not itself affect alanine absorption. Capsaicin reduced unidirectional mucosal-to-serosal alanine (1 mM) influx by 33%, an effect that becomes significant after 5 min of preincubation with capsaicin. Neonatal capsaicin treatment reduced basal alanine influx in jejunal strips by 37%; however, preincubation of these strips with capsaicin had no significant effect. Kinetic analysis of alanine steady-state uptake and influx by jejunal strips incubated with capsaicin revealed that capsaicin reduced the Na+-dependent component of alanine influx into intestinal epithelial cells. Long-term sensory denervation by capsaicin also decreased the Na+-dependent component of alanine absorption. These data suggest that intestinal capsaicin-sensitive primary afferent fibers regulate Na+-dependent amino acid absorption.

scholarly journals LY900009 Regulates RANKL-Induced Osteoclast Formation and LPS-Induced Bone Resorption

2020 ◽  
Author(s):  
Tao Huang ◽  
Congyun Zhao ◽  
Yi Zhao ◽  
Yuan Zhou ◽  
Lei Wang ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Suppressive Effect ◽  
Inhibitory Effect ◽  
Osteoclast Formation ◽  
Dependent Manner ◽  
In Vivo Experiments ◽  
Secretase Inhibitor ◽  
Formation Number

Abstract To investigate the suppressive function of LY900009, a potent-secretase inhibitor, on RANKL-induced osteoclastogenesis. The cytotoxicity of LY900009 was evaluated. The suppressive effect and possible molecular mechanism of LY900009 on RANKL-induced osteoclastogenesis was evaluated both in vitro and in vivo. The IC50 of LY900009 was 2.93 mM. LY900009 treatment at different doses (100 nM, 200 nM, and 400 nM) effectively reduced osteoclast formation (number and arear) in a dose-dependent manner. The qPCR result shows that LY900009 attenuates RANKL-induced osteoclast formation and NFATc1 protein expression. The in vivo experiments demonstrated the inhibitory effect of LY900009 on LPS-induced bone resorption. LY900009 could potently inhibit osteoclastogenesis and bone resorption by down-regulating Notch/MAPK/Akt - mediated NFATc1 reduction in vitro. In accordance with the in vitro observations, we confirmed that LY900009 attenuated LPS-induced osteolysis in mice. In conclusion, our findings indicate that Notch was a potential therapeutic target which could be used for osteolytic diseases treatment.

Selective inhibition of endothelium-dependent dilation in resistance-sized vessels in vivo

1987 ◽  
Vol 253 (2) ◽  
pp. H234-H239 ◽  
Author(s):  
U. Pohl ◽  
L. Dezsi ◽  
B. Simon ◽  
R. Busse
Keyword(s):  
Potent Inhibitor ◽  
Selective Inhibition ◽  
Dependent Manner ◽  
Sham Treatment ◽  
In Vivo Experiments ◽  
Before And After ◽  
Dose Dependent

In vivo experiments were performed in autoperfused hindlimbs of rabbits to investigate the role of endothelium-mediated vasomotion in resistance-sized vessels. The flow responses to the vasodilators acetylcholine (ACh), ATP, and substance P (SP), all of which have been shown to act in an endothelium-dependent manner in large conduit arteries, were studied before and after exposure of the hindleg vasculature to gossypol (a potent inhibitor of endothelium-mediated vasodilation in vitro). The flow responses to adenosine (ADO), nitroglycerin (GTN), and prostaglandin E2 (PGE2), which induce relaxation by a direct effect on vascular smooth muscle, were tested in the same manner. All vasodilators induced dose-dependent increases in femoral flow up to two- to threefold when administered intra-arterially. After gossypol, the flow responses to the endothelium-dependent compounds (ACh, ATP, and SP) were severely reduced (by 88 +/- 3%, P less than 0.01) or sometimes were converted to constrictions (ATP). The flow increases induced by ADO, PGE2, and GTN remained largely unaffected. Sham treatment (gossypol solute only), exposure to indomethacin (10 microM), and ganglionic blockade had no differential effect on the flow responses. The selective action of gossypol in suppressing the flow responses to the endothelium-dependent compounds ACh, ATP, and SP is consistent with a vasomotor role for endothelial cells in resistance-sized vessels in vivo.

scholarly journals Secreted KIAA1199 promotes the progression of rheumatoid arthritis by mediating hyaluronic acid degradation in an ANXA1-dependent manner

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wei Zhang ◽  
Guoyu Yin ◽  
Heping Zhao ◽  
Hanzhi Ling ◽  
Zhen Xie ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Hyaluronic Acid ◽  
Dependent Manner ◽  
Collagen Induced Arthritis ◽  
Intracellular Degradation ◽  
Main Pathway ◽  
First Time

AbstractIn inflamed joints, enhanced hyaluronic acid (HA) degradation is closely related to the pathogenesis of rheumatoid arthritis (RA). KIAA1199 has been identified as a hyaladherin that mediates the intracellular degradation of HA, but its extracellular function remains unclear. In this study, we found that the serum and synovial levels of secreted KIAA1199 (sKIAA1199) and low-molecular-weight HA (LMW-HA, MW < 100 kDa) in RA patients were significantly increased, and the positive correlation between them was shown for the first time. Of note, treatment with anti-KIAA1199 mAb effectively alleviated the severity of arthritis and reduced serum LMW-HA levels and cytokine secretion in collagen-induced arthritis (CIA) mice. In vitro, sKIAA1199 was shown to mediate exogenous HA degradation by attaching to the cell membrane of RA fibroblast-like synoviosytes (RA FLS). Furthermore, the HA-degrading activity of sKIAA1199 depended largely on its adhesion to the membrane, which was achieved by its G8 domain binding to ANXA1. In vivo, kiaa1199-KO mice exhibited greater resistance to collagen-induced arthritis. Interestingly, this resistance could be partially reversed by intra-articular injection of vectors encoding full-length KIAA1199 instead of G8-deleted KIAA119 mutant, which further confirmed the indispensable role of G8 domain in KIAA1199 involvement in RA pathological processes. Mechanically, the activation of NF-κB by interleukin-6 (IL-6) through PI3K/Akt signaling is suggested to be the main pathway to induce KIAA1199 expression in RA FLS. In conclusion, our study supported the contribution of sKIAA1199 to RA pathogenesis, providing a new therapeutic target for RA by blocking sKIAA1199-mediated HA degradation.

scholarly journals Phaseolin Attenuates Lipopolysaccharide-Induced Inflammation in RAW 264.7 Cells and Zebrafish

Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 420
Author(s):  
Su-Jung Hwang ◽  
Ye-Seul Song ◽  
Hyo-Jong Lee
Keyword(s):  
Nitric Oxide ◽  
Nuclear Translocation ◽  
Raw 264.7 Cells ◽  
Network Pharmacology ◽  
Raw 264.7 ◽  
Dependent Manner ◽  
Bioactive Constituents

Kushen (Radix Sophorae flavescentis) is used to treat ulcerative colitis, tumors, and pruritus. Recently, phaseolin, formononetin, matrine, luteolin, and quercetin, through a network pharmacology approach, were tentatively identified as five bioactive constituents responsible for the anti-inflammatory effects of S. flavescentis. However, the role of phaseolin (one of the primary components of S. flavescentis) in the direct regulation of inflammation and inflammatory processes is not well known. In this study, the beneficial role of phaseolin against inflammation was explored in lipopolysaccharide (LPS)-induced inflammation models of RAW 264.7 macrophages and zebrafish larvae. Phaseolin inhibited LPS-mediated production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS), without affecting cell viability. In addition, phaseolin suppressed pro-inflammatory mediators such as cyclooxygenase 2 (COX-2), interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and interleukin-6 (IL-6) in a dose-dependent manner. Furthermore, phaseolin reduced matrix metalloproteinase (MMP) activity as well as macrophage adhesion in vitro and the recruitment of leukocytes in vivo by downregulating Ninjurin 1 (Ninj1), an adhesion molecule. Finally, phaseolin inhibited the nuclear translocation of nuclear factor-kappa B (NF-κB). In view of the above, our results suggest that phaseolin could be a potential therapeutic candidate for the management of inflammation.

scholarly journals Synthesis and Characterization of Polyvinylpyrrolidone-Modified ZnO Quantum Dots and Their In Vitro Photodynamic Tumor Suppressive Action

2021 ◽  
Vol 22 (15) ◽  
pp. 8106
Author(s):  
Tianming Song ◽  
Yawei Qu ◽  
Zhe Ren ◽  
Shuang Yu ◽  
Mingjian Sun ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Photodynamic Therapy ◽  
Inhibitory Effect ◽  
Therapeutic Effects ◽  
In Vivo Experiments ◽  
Potential Applications ◽  
Zno Quantum Dots ◽  
Zno Qds

Despite the numerous available treatments for cancer, many patients succumb to side effects and reoccurrence. Zinc oxide (ZnO) quantum dots (QDs) are inexpensive inorganic nanomaterials with potential applications in photodynamic therapy. To verify the photoluminescence of ZnO QDs and determine their inhibitory effect on tumors, we synthesized and characterized ZnO QDs modified with polyvinylpyrrolidone. The photoluminescent properties and reactive oxygen species levels of these ZnO/PVP QDs were also measured. Finally, in vitro and in vivo experiments were performed to test their photodynamic therapeutic effects in SW480 cancer cells and female nude mice. Our results indicate that the ZnO QDs had good photoluminescence and exerted an obvious inhibitory effect on SW480 tumor cells. These findings illustrate the potential applications of ZnO QDs in the fields of photoluminescence and photodynamic therapy.

scholarly journals PapRIV, a BV-2 microglial cell activating quorum sensing peptide

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yorick Janssens ◽  
Nathan Debunne ◽  
Anton De Spiegeleer ◽  
Evelien Wynendaele ◽  
Marta Planas ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Cell Model ◽  
Dependent Manner ◽  
Communication Signals ◽  
Gram Positive Bacteria ◽  
A Cell ◽  
Gastro Intestinal Tract

AbstractQuorum sensing peptides (QSPs) are bacterial peptides produced by Gram-positive bacteria to communicate with their peers in a cell-density dependent manner. These peptides do not only act as interbacterial communication signals, but can also have effects on the host. Compelling evidence demonstrates the presence of a gut-brain axis and more specifically, the role of the gut microbiota in microglial functioning. The aim of this study is to investigate microglial activating properties of a selected QSP (PapRIV) which is produced by Bacillus cereus species. PapRIV showed in vitro activating properties of BV-2 microglia cells and was able to cross the in vitro Caco-2 cell model and reach the brain. In vivo peptide presence was also demonstrated in mouse plasma. The peptide caused induction of IL-6, TNFα and ROS expression and increased the fraction of ameboid BV-2 microglia cells in an NF-κB dependent manner. Different metabolites were identified in serum, of which the main metabolite still remained active. PapRIV is thus able to cross the gastro-intestinal tract and the blood–brain barrier and shows in vitro activating properties in BV-2 microglia cells, hereby indicating a potential role of this quorum sensing peptide in gut-brain interaction.

scholarly journals The Extracellular Small Leucine-Rich Proteoglycan Biglycan Is a Key Player in Gastric Cancer Aggressiveness

Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1330
Author(s):  
Filipe Pinto ◽  
Liliana Santos-Ferreira ◽  
Marta T. Pinto ◽  
Catarina Gomes ◽  
Celso A. Reis
Keyword(s):  
Clinical Value ◽  
Knock Out ◽  
Angiogenic Potential ◽  
In Vivo Experiments ◽  
Cancer Aggressiveness ◽  
Advanced Stages ◽  
Oncogenic Gene

Biglycan (BGN gene), an extracellular proteoglycan, has been described to be associated with cancer aggressiveness. The purpose of this study was to clarify the clinical value of biglycan as a biomarker in multiple independent GC cohorts and determine the in vitro and in vivo role of biglycan in GC malignant features. We found that BGN is commonly over-expressed in all analyzed cohorts, being associated with disease relapse and poor prognosis in patients with advanced stages of disease. In vitro and in vivo experiments demonstrated that biglycan knock-out GC cells display major phenotypic changes with a lower cell survival, migration, and angiogenic potential when compared with biglycan expressing cells. Biglycan KO GC cells present increased levels of PARP1 and caspase-3 cleavage and a decreased expression of mesenchymal markers. Importantly, biglycan deficient GC cells that were supplemented with exogenous biglycan were able to restore biological features, such as survival, clonogenic and migratory capacities. Our in vitro and in vivo findings were validated in human GC samples, where BGN expression was associated with several oncogenic gene signatures that were associated with apoptosis, cell migration, invasion, and angiogenesis. This study provided new insights on biglycan role in GC that should be taken in consideration as a key cellular regulator with major impact in tumor progression and patients’ clinical outcome.

Paradoxical effect of salbutamol in a model of acute organophosphates intoxication in guinea pigs: role of substance P release

2007 ◽  
Vol 292 (4) ◽  
pp. L915-L923 ◽  
Author(s):  
Jaime Chávez ◽  
Patricia Segura ◽  
Mario H. Vargas ◽  
José Luis Arreola ◽  
Edgar Flores-Soto ◽  
...  
Keyword(s):  
Substance P ◽  
Guinea Pigs ◽  
Smooth Muscle Contraction ◽  
In Vivo Experiments ◽  
Intracellular Ca ◽  
Neurokinin 1 ◽  
Substance P Release

Organophosphates induce bronchoobstruction in guinea pigs, and salbutamol only transiently reverses this effect, suggesting that it triggers additional obstructive mechanisms. To further explore this phenomenon, in vivo (barometric plethysmography) and in vitro (organ baths, including ACh and substance P concentration measurement by HPLC and immunoassay, respectively; intracellular Ca2+ measurement in single myocytes) experiments were performed. In in vivo experiments, parathion caused a progressive bronchoobstruction until a plateau was reached. Administration of salbutamol during this plateau decreased bronchoobstruction up to 22% in the first 5 min, but thereafter airway obstruction rose again as to reach the same intensity as before salbutamol. Aminophylline caused a sustained decrement (71%) of the parathion-induced bronchoobstruction. In in vitro studies, paraoxon produced a sustained contraction of tracheal rings, which was fully blocked by atropine but not by TTX, ω-conotoxin (CTX), or epithelium removal. During the paraoxon-induced contraction, salbutamol caused a temporary relaxation of ∼50%, followed by a partial recontraction. This paradoxical recontraction was avoided by the M2- or neurokinin-1 (NK1)-receptor antagonists (methoctramine or AF-DX 116, and L-732138, respectively), accompanied by a long-lasting relaxation. Forskolin caused full relaxation of the paraoxon response. Substance P and, to a lesser extent, ACh released from tracheal rings during 60-min incubation with paraoxon or physostigmine, respectively, were significantly increased when salbutamol was administered in the second half of this period. In myocytes, paraoxon did not produce any change in the intracellular Ca2+ basal levels. Our results suggested that: 1) organophosphates caused smooth muscle contraction by accumulation of ACh released through a TTX- and CTX-resistant mechanism; 2) during such contraction, salbutamol relaxation is functionally antagonized by the stimulation of M2 receptors; and 3) after this transient salbutamol-induced relaxation, a paradoxical contraction ensues due to the subsequent release of substance P.

Immunomodulatory activities of whey fractions in efferent prefemoral lymph of sheep

1996 ◽  
Vol 63 (2) ◽  
pp. 257-267 ◽  
Author(s):  
Chun W. Wong ◽  
Geoffrey O. Regester ◽  
Geoffrey L. Francis ◽  
Dennis L. Watson
Keyword(s):  
Immune Responses ◽  
Bovine Milk ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Milk Whey ◽  
Significant Difference ◽  
Lymphocyte Phenotypes ◽  
Dose Dependent

SummaryStudies on the immunomodulatory activities of ruminant milk and colostral whey fractions were undertaken. By comparing with boiled colostral whey in a preliminary experiment, a putative heat-labile immunostimulatory factor for antibody responses was found to be present in ovine colostral whey. Studies were then undertaken in sheep in which the efferent prefemoral lymphatic ducts were cannulated bilaterally, and immune responses in the node were measured following subcutaneous injection in the flank fold of whey protein preparations of various purities. A significant sustained decline of efferent lymphocyte output was observed following injection with autologous crude milk whey or colostral whey preparations, but no changes were observed in interferon-gamma levels in lymph plasma. Two bovine milk whey fractions (lactoperoxidase and lactoferrin) of high purity were compared in bilaterally cannulated sheep. A transient decline over the first 6 h was seen in the efferent lymphocyte output and lymph flow rate after injection of both fractions. A significant difference was seen between the two fractions in interferongamma levels in lymph at 6 h after injection. However, no significant changes in the proportion of the various efferent lymphocyte phenotypes were seen following either treatment. Whereas both fractions showed a significant inhibitory effect in a dose-dependent manner on the proliferative response of T lymphocytes, but not B lymphocytes, to mitogenic stimulation in vitro, no similar changes were seen following in vivo stimulation with these two fractions.

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