Prostaglandins mediate tonic contraction of the guinea pig and human gallbladder

2007 ◽  
Vol 292 (1) ◽  
pp. G409-G418 ◽  
Author(s):  
Ping Cong ◽  
Zuo-Liang Xiao ◽  
Piero Biancani ◽  
Jose Behar
Keyword(s):  
Protein Expression ◽  
Tonic Contraction ◽  
Human Gallbladder ◽  
Small Interference Rna ◽  
Cox Inhibitors ◽  
Cox Inhibitor ◽  
Cox 2 ◽  
Dose Dependent Decrease ◽  
Dose Dependent ◽  
Cox 1

The gallbladder (GB) maintains tonic contraction modulated by neurohormonal inputs but generated by myogenic mechanisms. The aim of these studies was to examine the role of prostaglandins in the genesis of GB myogenic tension. Muscle strips and cells were treated with prostaglandin agonists, antagonists, cyclooxygenase (COX) inhibitors, and small interference RNA (siRNA). The results show that PGE2, thromboxane A2 (TxA2), and PGF2α cause a dose-dependent contraction of muscle strips and cells. However, only TxA2 and PGE2 (E prostanoid 1 receptor type) antagonists induced a dose-dependent decrease in tonic tension. A COX-1 inhibitor decreased partially the tonic contraction and TxB2 (TxA2 stable metabolite) levels; a COX-2 inhibitor lowered the tonic contraction partially and reduced PGE2 levels. Both inhibitors and the nonselective COX inhibitor indomethacin abolished the tonic contraction. Transfection of human GB muscle strips with COX-1 siRNA partially lowered the tonic contraction and reduced COX-1 protein expression and TxB2 levels; COX-2 siRNA also partially reduced the tonic contraction, the protein expression of COX-2, and PGE2. Stretching muscle strips by 1, 2, 3, and 4 g increased the active tension, TxB2, and PGE2 levels; a COX-1 inhibitor prevented the increase in tension and TxB2; and a COX-2 inhibitor inhibited the expected rise in tonic contraction and PGE2. Indomethacin blocked the rise in tension and TxB2 and PGE2 levels. We conclude that PGE2 generated by COX-2 and TxA2 generated by COX-1 contributes to the maintenance of GB tonic contraction and that variations in tonic contraction are associated with concomitant changes in PGE2 and TxA2 levels.

Simultaneous inhibition of TXA2 and PGI2 synthesis increases NO release in mesenteric resistance arteries from cirrhotic rats

2010 ◽  
Vol 119 (7) ◽  
pp. 283-292 ◽  
Author(s):  
Fabiano E. Xavier ◽  
Javier Blanco-Rivero ◽  
Esther Sastre ◽  
Lina Badimón ◽  
Gloria Balfagón
Keyword(s):  
Protein Expression ◽  
Resistance Arteries ◽  
Synthesis Inhibitor ◽  
Thromboxane A2 Receptor ◽  
Vasodilator Response ◽  
Cox Inhibitor ◽  
No Release ◽  
Simultaneous Inhibition ◽  
Cox 2 ◽  
Cox 1

Our present study examines, in mesenteric resistance arteries, possible vasodilation alterations, and the role of NO and COX (cyclo-oxygenase) derivatives, in cirrhosis. The vasodilator response to acetylcholine was analysed in segments from control and cirrhotic rats. The effects of the non-specific COX inhibitor indomethacin, the specific COX-1 inhibitor SC-560 and the specific COX-2 inhibitor NS-398 were analysed in segments from both groups of rats. NO release was measured, and eNOS [endothelial NOS (NO synthase)], phospho-eNOS, iNOS (inducible NOS), COX-1 and COX-2 protein expression was also analysed. The effects of the TP receptor [TXA2 (thromboxane A2) receptor] antagonist SQ 29548, the TXA2 synthesis inhibitor furegrelate, the PGI2 (prostaglandin I2) synthesis inhibitor TCP (tranylcypromine) or TCP+furegrelate were only determined in segments from cirrhotic rats. The vasodilator response to acetylcholine was higher in segments from cirrhotic rats. Indomethacin, SC-560 and NS-398 did not modify the vasodilator response in control rats; however, indomethacin, NS-398 and TCP+furegrelate increased, whereas SC-560 did not modify and SQ 29548, furegrelate or TCP decreased, the vasodilator response to acetylcholine in cirrhotic rats. NO release was higher in cirrhotic rats. Furegrelate decreased, whereas TCP+furegrelate increased, the NO release in segments from cirrhotic rats. eNOS and COX-1 protein expression was not modified, whereas phosho-eNOS, iNOS and COX-2 protein expression was higher in cirrhotic rats. Therefore the increase in iNOS expression and eNOS activity may mediate increases in endothelial NO release. The COX-2 derivatives TXA2 and PGI2 may act simultaneously, producing a compensatory effect that reduces NO release and may limit the hyperdynamic circulation.

scholarly journals Synthesis and theoretical activity evaluation of a new steroid-oxazolone derivative against COX1-1 and COX-2

2019 ◽  
Vol 9 (4) ◽  
pp. 4107-4113
Keyword(s):  
Elemental Analysis ◽  
Cox Inhibitors ◽  
Activity Evaluation ◽  
Docking Model ◽  
Cox Inhibitor ◽  
Cox 2 ◽  
Cox 1

There are some reports for the preparation of several drugs as cyclooxygenase (COX) inhibitors; however, some reagents used in the preparation are expensive and difficult to handle. The aim of this study was to synthesize a steroid-oxazolone derivativeusing some reactions such as i) hydroxylation-amiination; ii) amidation; iii) alkynyl-addition; iv) aldolization and iv) imination. In addition, a theoretical ass was carried out to evaluate the interaction of both COX-1 and COX-2 with the steroid-oxazolone derivativeusing indomethacin and rofecoxib as controls in a docking model. The structure of the compounds obtained was confirmed through elemental analysis, spectroscopy and spectrometry data. The results showed that there are differences between the interaction of the steroidoxazolone derivativewith both COX 1 and COX 2 compared with the bound of indomethacin and rofecoxib with this type of enzymes. These data suggest that the steroid-oxazolone derivativecould be a good candidate as COX-inhibitor translated as a possible drug for treatment of pain.

Effects of cyclooxygenase inhibition on canine coronary artery blood flow and thrombosis

2008 ◽  
Vol 294 (1) ◽  
pp. H145-H155 ◽  
Author(s):  
Ting-Ting Hong ◽  
Jinbao Huang ◽  
Terrance D. Barrett ◽  
Benedict R. Lucchesi
Keyword(s):  
Coronary Artery ◽  
Vascular Reactivity ◽  
Thrombus Formation ◽  
Normal Coronary Artery ◽  
Cox Inhibitors ◽  
Inflammatory Conditions ◽  
Cox Inhibitor ◽  
Cox 2 ◽  
Cox 2 Inhibitors ◽  
Cox 1

This study was designed to determine the effect of inhibitors of cyclooxygenase (COX)-1, COX-2, and the nonselective COX inhibitor naproxen on coronary vasoactivity and thrombogenicity under baseline and lipopolysaccharide (LPS)-induced inflammatory conditions. We hypothesize that endothelial COX-1 is the primary COX isoform in the canine normal coronary artery, which mediates arachidonic acid (AA)-induced vasodilatation. However, COX-2 can be induced and overexpressed by inflammatory mediators and becomes the major local COX isoform responsible for the production of antithrombotic prostaglandins during systemic inflammation. The interventions included the selective COX-1 inhibitor SC-560 (0.3 mg/kg iv), the selective COX-2 inhibitor nimesulide (5 mg/kg iv), or the nonselective COX inhibitor naproxen (3 mg/kg iv). The selective prostacyclin (IP) receptor antagonist RO-3244794 (RO) was used as an investigational tool to delineate the role of prostacyclin (PGI2) in modulating vascular reactivity. AA-induced vasodilatation of the left circumflex coronary artery was suppressed to a similar extent by each of the COX inhibitors and RO. The data suggest that AA-induced vasodilatation in the normal coronary artery is mediated by a single COX isoform, the constitutive endothelial COX-1, which is reported to be susceptible to COX-2 inhibitors. The effect of the COX inhibitors on thrombus formation was evaluated in a model of carotid artery thrombosis secondary to electrolytic-induced vessel wall injury. Pretreatment with LPS (0.5 mg/kg iv) induced a systemic inflammatory response and prolonged the time-to-occlusive thrombus formation, which was reduced in the LPS-treated animals by the administration of nimesulide. In contrast, neither SC-560 nor naproxen influenced the time to thrombosis in the animals pretreated with LPS. The data are of significance in view of reported adverse cardiovascular events observed in clinical trials involving the use of selective COX-2 inhibitors, thereby suggesting that the endothelial constitutive COX-1 and the inducible vascular COX-2 serve important functions in maintaining vascular homeostasis.

scholarly journals Rapid and transient induction of cyclo-oxygenase 2 by epidermal growth factor in human amnion-derived WISH cells

1997 ◽  
Vol 321 (3) ◽  
pp. 677-681 ◽  
Author(s):  
Douglas J. PERKINS ◽  
Douglas A. KNISS
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Protein Expression ◽  
De Novo ◽  
Tnf Α ◽  
Mrna And Protein Expression ◽  
Epidermal Growth ◽  
Cox 2 ◽  
Dose Dependent ◽  
Cox 1

The central enzyme in the prostaglandin (PG) biosynthetic cascade is PGH2 synthase or cyclo-oxygenase (COX). At present, two distinct isoforms of PGH2 synthase/COX have been identified: COX-1 and COX-2. In many systems, COX-1 is a constitutively expressed isoform that is responsible for normal physiological production of PGs, whereas COX-2 is an inducible isoform that responds to cytokines, endotoxin and growth factors by producing high levels of PGs. The regulation of COX-2 mRNA and protein, and the subsequent production of PGE2, were therefore examined in amnion-derived WISH cells stimulated with epidermal growth factor (EGF). Treatment of WISH cells with EGF (0.01Ő100 ng/ml) elicited dose-dependent synthesis of COX-2 mRNA and protein de novo. In addition, stimulation of WISH cells with EGF (10 ng/ml) induced steady-state levels of COX-2 mRNA and protein that appeared within 30 min and then declined rapidly to near baseline levels within 2Ő4 h. In contrast, COX-1 protein was unchanged in response to treatment with EGF. PGE2 production was also rapid and transient. Preincubation of cells with the novel COX-2 enzymic inhibitor NS-398 (10-5Ő10-10 M) completely prevented PGE2 formation in a dose-dependent manner. Preincubation of cells in dexamethasone (Dex; 0.1 ƁM), however, resulted in only a 31% decrease in PGE2 formation in response to EGF (10 ng/ml) while completely attenuating PGE2 biosynthesis in tumour necrosis factor α (TNF-α)-stimulated cells. In addition, Dex (0.1 ƁM) was only partly effective at preventing EGF-induced COX-2 mRNA and protein expression de novo, whereas Dex completely inhibited TNF-α-promoted COX-2 mRNA and protein expression. Thus the results presented here demonstrate that EGF induces the rapid but transient expression of COX-2 mRNA and protein and the subsequent production of PGE2 in WISH cells.

Mechanisms underlying the contraction induced by bradykinin in the guinea pig epithelium-denuded trachea

2002 ◽  
Vol 80 (4) ◽  
pp. 360-367 ◽  
Author(s):  
Valfredo Schlemper ◽  
João B Calixto
Keyword(s):  
Nitric Oxide ◽  
Guinea Pig ◽  
Rank Order ◽  
Nitric Oxide Synthase Inhibitor ◽  
Cox Inhibitors ◽  
Cyclooxygenase 1 ◽  
Cox Inhibitor ◽  
Cox 2 ◽  
Synthase Inhibitor ◽  
Cox 1

This study investigates some of the mechanisms by which bradykinin (BK) triggers contraction of epithelium-denuded strips of guinea pig trachea (GPT). Cumulative or single additions of BK, T-BK, L-BK, or ML-BK in the presence of captopril (30 µM) produced graded GPT contractions with the following rank order of potency (EC50 level): T-BK (31.3 nM) > BK (40.0 nM) > L-BK (56.0 nM) > ML-BK (77.0 nM). BK-induced contraction (100 nM) in GPT was completely inhibited by either HOE 140 or NPC 17731 with mean IC50 values of 17 and 217 nM, respectively. Addition of BK (100 nM) at 30 min intervals, induced progressive tachyphylaxis, which was complete after 4 h. The tachyphylaxis induced by BK was unaffected by L-NOARG (nitric oxide synthase inhibitor, 100 µM) or valeryl salicylate (a cyclooxygenase-1 (COX-1) inhibitor, 30 µM), but was prevented by a low concentration of indomethacin, diclofenac (non-selective COX inhibitors, 3 nM each) or by NS 398 (a COX-2 inhibitor, 10 nM). Furthermore, higher concentrations of indomethacin, diclofenac, phenidone (a lypooxygenase (LOX) and COX inhibitor), or NS 398, caused graded inhibition of BK-induced contraction, with mean IC50 values of 0.28, 0.08, 46.37, and 0.15 µM, respectively. Together, these results suggest that BK-induced contraction in GPT involves activation of B2 receptors and release of prostanoids from COX-2 pathway. Furthermore, the tachyphylaxis induced by BK was insensitive to the nitric oxide and COX-1 inhibitors, but was prevented by non-selective and selective COX-2 inhibitors, indicating a mediation via COX-2-derived arachidonic acid metabolites.Key words: guinea pig trachea, bradykinin, B2 receptors, desensitization, prostaglandins.

Cyclooxygenase-2 plays a significant role in regulating the tone of the fetal lamb ductus arteriosus

1999 ◽  
Vol 276 (3) ◽  
pp. R913-R921 ◽  
Author(s):  
Ronald I. Clyman ◽  
Pierre Hardy ◽  
Nahid Waleh ◽  
Yao Qi Chen ◽  
Françoise Mauray ◽  
...  
Keyword(s):  
Significant Role ◽  
Ductus Arteriosus ◽  
Late Gestation ◽  
Relative Contribution ◽  
Cox Inhibitor ◽  
Fetal Lamb ◽  
Cox 2 ◽  
Cox 2 Inhibitors ◽  
Cox 1

Nonselective cyclooxygenase (COX) inhibitors are potent tocolytic agents but have adverse effects on the fetal ductus arteriosus. We hypothesized that COX-2 inhibitors may not affect the ductus if the predominant COX isoform is COX-1. To examine this hypothesis, we used ductus arteriosus obtained from late-gestation fetal lambs. In contrast to our hypothesis, fetal lamb ductus arteriosus expressed both COX-1- and COX-2-immunoreactive protein (by Western analysis). Although COX-1 was found in both endothelial and smooth muscle cells, COX-2 was found only in the endothelial cells lining the ductus lumen (by immunohistochemistry). The relative contribution of COX-1 and COX-2 to PGE2 synthesis was consistent with the immunohistochemical results: in the intact ductus, PGE2 formation was catalyzed by both COX-1 and COX-2 in equivalent proportions; in the endothelium-denuded ductus, COX-2 no longer played a significant role in PGE2 synthesis. NS-398, a selective inhibitor of COX-2, was 66% as effective as the selective COX-1 inhibitor valeryl salicylate and the nonselective COX inhibitor indomethacin in causing contraction of the ductus in vitro. At this time, caution should be used when recommending COX-2 inhibitors for use in pregnant women.

scholarly journals Effect of Bee Venom Pharmacopuncture on Inflammation in Mouse Model of Induced Atopic Dermatitis

2020 ◽  
Vol 37 (2) ◽  
pp. 123-127
Author(s):  
Kyeong Ju Park ◽  
Ho-Sueb Song
Keyword(s):  
Atopic Dermatitis ◽  
Mouse Model ◽  
Treated Group ◽  
Bee Venom ◽  
Related Protein ◽  
Griess Reaction ◽  
Cox 2 ◽  
Dose Dependent Decrease ◽  
Dose Dependent ◽  
Inflammatory Effect

Background: This study was designed using a mouse model of atopic dermatitis [phthalic anhydride (PA)-treated mice], to investigate the anti-inflammatory effect of bee venom pharmacopuncture (BVP) in keratinocytes.Methods: Western blot analysis was performed to investigate inflammation related protein expression of iNOS, COX-2, phospho-ERK (p-ERK), and ERK, in LPS (1 μg/mL)-activated keratinocytes, following BVP treatment, and in PA-treated mice, after BVP treatment. Griess reaction was performed to investigate NO concentration. Enzyme-linked immunosorbent assays were used to determine the concentrations of interleukin (IL)-4+, IL-17A+, IL-13 and IL-4 in PA-treated mice after BVP treatment. In addition, monocyte, macrophage, neutrophil, and eosinophil counts were measured to observe the changes in white blood cell infiltration.Results: The keratinocytes of the BVP-treated group showed a decreased expression of iNOS, COX-2, ERK at 5 OX-2, ERK E, and p-ERK at 1, 2 and 5 RKRK ERK ERK, and a dose-dependent decrease in NO concentration at 2 and 5 ntrationof s. In the BVP-treated groups (0.1 μ.1-trea μ.1-treated gr), PA-treated mice showed recovery after 4 weeks which was dose-dependent, showing a significant decrease in clinical scores for AD, and a decreased concentration of IL-13 and IL-4 with BV treatment. There was a dose-dependent decrease in the infiltration of eosinophils, neutrophils, monocytes, macrophages, and a decreased thickness of the epidermis due to inflammation, and decreased expressions of iNOS, COX-2, p-ERK, ERK, especially in the 0.1 μ0/mL BVP-treated group,<br>Conclusion: These results suggest that BVP may be an effective alternative treatment for atopic dermatitis.

scholarly journals Protection Effect of Self-Nanoemulsifying Drug Delivery System (SNEDDS) Piroxicam as Ulcerogenic Agent towards Malondialdehid Level and Protein Expression of Caspase-3, COX-1, COX-2 at Rat Gastric

2020 ◽  
pp. 273-283
Author(s):  
Iis Wahyuningsih ◽  
Kurnia Ambarwati ◽  
Erninda Ayu Hapsari ◽  
Afifah Fauziyyah ◽  
Azis Ikhsanudin ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Protein Expression ◽  
Drug Delivery System ◽  
Delivery System ◽  
Caspase 3 ◽  
Thiobarbituric Acid Reactive Substance ◽  
Sprague Dawley ◽  
Protection Effect ◽  
Cox 2 ◽  
Cox 1

The aim of this study was to determine the protection effect of SNEDDS piroxicam ulcerogenic agent against malondialdehyde (MDA) level and protein expression of caspase-3, COX-1, COX-2. The research was conducted using the test animals as much as 30 male white Sprague dawley (SD) rats aged 1-2 months with a weight of 100-200 grams divided into 5 groups. Treatment was given for 28 days orally. On the 29th day blood samples were also taken for the determination of MDA (Malondialdehid) levels by Thiobarbituric Acid Reactive Substance (TBARs) method using a visible spectrophotometer. Rats were sacrificed, then gastric organs were taken for immunohistochemical testing of caspase-3 and COX-1 expression, COX-2. The statistical analysis showed that the piroxicam SNEDDS group and the piroxicam suspension group decreased expression of the caspase-3 protein, increased COX-1 expression, decreased COX-2 and significantly decreased MDA levels. The piroxicam-containing SNEDDS (Self-Nanoemulsifying Drug Delivery System) form has protection against ulcogenic piroxicam.

Key role for constitutive cyclooxygenase-2 of MDCK cells in basal signaling and response to released ATP

2001 ◽  
Vol 281 (2) ◽  
pp. C524-C531 ◽  
Author(s):  
Rennolds S. Ostrom ◽  
Caroline Gregorian ◽  
Ryan M. Drenan ◽  
Kathryn Gabot ◽  
Brinda K. Rana ◽  
...  
Keyword(s):  
Cell Function ◽  
Mdck Cells ◽  
Second Messengers ◽  
Atp Release ◽  
Cox Inhibitors ◽  
Cox 2 ◽  
Factor Α ◽  
Biochemical Activation ◽  
Camp Formation ◽  
Cox 1

Madin-Darby canine kidney (MDCK) cells release ATP upon mechanical or biochemical activation, initiating P2Y receptor signaling that regulates basal levels of multiple second messengers, including cAMP ( J Biol Chem 275: 11735–11739, 2000). Data shown here document inhibition of cAMP formation by Gd3+ and niflumic acid, channel inhibitors that block ATP release. cAMP production is stimulated via Ca2+-dependent activation of cytosolic phospholipase A2, release of arachidonic acid (AA), and cyclooxygenase (COX)-dependent production of prostaglandins, which activate prostanoid receptors coupled to Gs and adenylyl cyclase. In the current investigation, we assessed the expression and functional role of the two known isoforms of COX, COX-1 and COX-2. Treatment of cells with either a COX-1-selective inhibitor, SC-560, or COX-2-selective inhibitors, SC-58125 or NS-398, inhibited basal and UTP-stimulated cAMP levels. COX inhibitors also decreased forskolin-stimulated cAMP formation, implying this response is in part attributable to an action of AA metabolites. These findings imply an important role for the inducible form of COX, COX-2, under basal conditions. Indeed, COX-2 expression was readily detectable by immunoblot, and treatments that induce or reduce COX-2 expression in other cells (interleukin-1β, tumor necrosis factor-α, phorbol ester, or dexamethasone) had minimal or no effect on the levels of COX-2 immunoreactivity. RT-PCR using isoform-specific primers detected COX-2 mRNA. We conclude that COX-2 is constitutively expressed in MDCK-D1 cells and participates in basal and P2Y2-mediated signaling, implying a key role for COX-2 in regulation of epithelial cell function.

scholarly journals Cyclooxygenases Inhibitors Efficiently Induce Cardiomyogenesis in Human Pluripotent Stem Cells

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 554 ◽  
Author(s):  
Harshal Nemade ◽  
Aviseka Acharya ◽  
Umesh Chaudhari ◽  
Erastus Nembo ◽  
Filomain Nguemo ◽  
...  
Keyword(s):  
Wnt Signaling Pathway ◽  
Calcium Transient ◽  
Cardiac Differentiation ◽  
Cyclooxygenase Inhibitors ◽  
Cox Inhibitors ◽  
Screening Model ◽  
Cox 2 ◽  
Transient Measurements ◽  
Cox 1

Application of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) is limited by the challenges in their efficient differentiation. Recently, the Wingless (Wnt) signaling pathway has emerged as the key regulator of cardiomyogenesis. In this study, we evaluated the effects of cyclooxygenase inhibitors on cardiac differentiation of hPSCs. Cardiac differentiation was performed by adherent monolayer based method using 4 hPSC lines (HES3, H9, IMR90, and ES4SKIN). The efficiency of cardiac differentiation was evaluated by flow cytometry and RT-qPCR. Generated hPSC-CMs were characterised using immunocytochemistry, electrophysiology, electron microscopy, and calcium transient measurements. Our data show that the COX inhibitors Sulindac and Diclofenac in combination with CHIR99021 (GSK-3 inhibitor) efficiently induce cardiac differentiation of hPSCs. In addition, inhibition of COX using siRNAs targeted towards COX-1 and/or COX-2 showed that inhibition of COX-2 alone or COX-1 and COX-2 in combination induce cardiomyogenesis in hPSCs within 12 days. Using IMR90-Wnt reporter line, we showed that inhibition of COX-2 led to downregulation of Wnt signalling activity in hPSCs. In conclusion, this study demonstrates that COX inhibition efficiently induced cardiogenesis via modulation of COX and Wnt pathway and the generated cardiomyocytes express cardiac-specific structural markers as well as exhibit typical calcium transients and action potentials. These cardiomyocytes also responded to cardiotoxicants and can be relevant as an in vitro cardiotoxicity screening model.

Sign in / Sign up

Export Citation Format

Share Document