scholarly journals Characterization of α2-Adrenergic Receptors Mediated Vasoconstriction in ex vivo model

2021 ◽  
Author(s):  
Molly Yao
Keyword(s):  
Adrenergic Receptor ◽  
Vascular Tone ◽  
Ex Vivo ◽  
Receptor Activation ◽  
Lateral Vein ◽  
Contractile Property ◽  
Temperature Changes ◽  
Selective Agonists ◽  
Cutaneous Circulation ◽  
Rat Tail

AbstractIntroductionrat tail serves as a thermoregulatory organ by dilating or constricting tail blood vessels and rat tail lateral veins play a role in cutaneous circulation. However, this cutaneous vessel has never been examined and evaluated as a potential candidate ex vivo model to study peripheral vascular diseases. This study aims to investigate vascular tone mediated through α2-adenergic receptor on rat tail vein under different temperatures.MethodsVasoconstriction stimulated by α2-adrenergic receptor selective agonists UK14304, guanabenz was thoroughly examined in isolated rat tail lateral vein. Susceptibility of cutaneous vessel to temperature changes was investigated under 37 °C and 28 °C. Differentiated vascular reactivity exhibited at different temperature was further explored with different α2-adrenergic receptor selective agonists and validated with antagonism by α1-adrenergic receptor and α2-adrenergic receptor selective antagonist prazosin and RX821002, respectively.ResultsVascular tone of freshly isolated vein remained same compared with that of stored in pre-gassed physiologic buffer at 4 °C overnight. Presence of endothelium and repeated administration of UK14304 did not alter contractile property. Vessels away from torso (distal) showed significantly different contractile character compared with portion close to torso (proximal) at 28 °C but kept uniform at 37 °C. Enhanced vasoconstriction along with increased potency of α2-adrenergic receptor agonists UK14304 and guanabenz was consistently present at 28 °C, independent of temperature change orders. Potentiated vasoconstriction present at 28 °C was later proved via α2-adrenergic receptor alone.DiscussionHarvest and preparation of rat tail lateral vein was described in details. Contractile property of venous preparations stimulated by α2-adrenergic receptor selective agonists was first time examined. Differentiated vasoconstriction at moderate cooling temperature was described and confirmed to through α2-adrenergic receptor activation. Rat tail lateral vein is found valuable for studies of cutaneous circulation altered by temperature changes.

Abstract 459: Vasoactivity of the Alzheimer ß-Amyloid Peptides is Mediated by an Activation of the a 1 -Adrenoreceptor

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Nadine Haase ◽  
Florian Herse ◽  
Bastian Spallek ◽  
Hannelore Haase ◽  
Gerd Wallukat ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Adrenergic Receptor ◽  
Ex Vivo ◽  
Receptor Activation ◽  
Negative Control ◽  
Amyloid Peptide ◽  
Receptor Blocker ◽  
Ex Vivo Model ◽  
Aβ Amyloid

Alzheimer disease (AD) features β-amyloid peptide (Aβ) deposition in brain and blood vessels and is associated with hypertension. Aβ can cause vasoconstriction and endothelial dysfunction. Recently, we could show that Aβ peptides elicit a signal transduction pathway in vascular smooth muscle cells and cardiomyocytes, induced by α 1 -adrenergic receptor activation. We hypothesized that the Aβ vasoactivity is also induced by activation of the α 1 -adrenoreceptor. Mouse aortic Rings were incubated for 24 h with 1 μmol/l Aβ (25-35). The influence of Aβ (25-35) on vasoconstriction of mouse aortic rings was studied in the additional presence and absence of α 1 -adrenergic receptor blocker prazosin. Vasoactivity in isolated aortic rings was measured using an isometric myograph. Vasoconstriction to 5-hydroxytryptamine was significantly increased (P≤0.001) in aortic rings by Aβ (25-35) pretreatment. This vasoactive effect was improved by the presence of α 1 -adrenergic receptor blocker during the Aβ (25-35) pretreatment. Rat middle cerebral artery (MCA) segments were treated with either 0.1μmol/L Aβ (25-35) or 0.1μmol/L of a negative control peptide with a reverse amino acid sequence (Aβ rev.) of Aβ (25-35) for 4h. Constriction of the middle cerebral artery was measured in dual vessel chamber. Incubation with Aβ (25-35) significantly enhanced (P≤0.0005) response of middle cerebral artery segments to the α 1 -agonist phenylephrine induced contractions. In a further ex vivo model of Langendorff-perfused rat hearts Aβ (25-35) also induced vasoconstriction of coronary arteries that resulted in decreased coronary flow. These effects could also be reversed by α 1 -adrenergic receptor blockade. Furthermore we analyzed the brain of hypertensive dTGR animals and in human arteriosclerotic plaques for the presence of Aβ amyloid. Amyloid deposits are present in cerebral cortex of hypertensive dTGR animals with damaged blood-brain barrier and in human arteriosclerotic plaques. Our data are relevant to the association between AD and hypertension. They may serve to explain impaired of vascular responses by Aβ and could have therapeutic implications.

scholarly journals An Increase in Murine Skeletal Muscle Peroxisome Proliferator-Activated Receptor-γ Coactivator-1α (PGC-1α) mRNA in Response to Exercise Is Mediated by β-Adrenergic Receptor Activation

Endocrinology ◽  
2007 ◽  
Vol 148 (7) ◽  
pp. 3441-3448 ◽  
Author(s):  
Shinji Miura ◽  
Kentaro Kawanaka ◽  
Yuko Kai ◽  
Mayumi Tamura ◽  
Masahide Goto ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mrna Expression ◽  
Adrenergic Receptor ◽  
Ex Vivo ◽  
Specific Inhibitor ◽  
Receptor Activation ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Brown Adipose ◽  
Exercise Induced

A single bout of exercise increases expression of peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α mRNA, which may promote mitochondrial biogenesis in skeletal muscle. In brown adipose tissue, cold exposure up-regulates PGC-1α expression via adrenergic receptor (AR) activation. Because exercise also activates the sympathetic nervous system, we examined whether exercise-induced increase in PGC-1α mRNA expression in skeletal muscle was mediated via AR activation. In C57BL/6J mice, injection of the β2-AR agonist clenbuterol, but not α-, β1-, or β3-AR agonists, increased PGC-1α mRNA expression more than 30-fold in skeletal muscle. The clenbuterol-induced increase in PGC-1α mRNA expression in mice was inhibited by pretreatment with the β-AR antagonist propranolol. In ex vivo experiments, direct exposure of rat epitrochlearis to β2-AR agonist, but not α-, β1-, and β3-AR agonist, led to an increase in levels of PGC-1α mRNA. Injection of β2-AR agonist did not increase PGC-1α mRNA expression in β1-, β2-, and β3-AR knockout mice (β-less mice). PGC-1α mRNA in gastrocnemius was increased 3.5-fold in response to running on a treadmill for 45 min. The exercise-induced increase in PGC-1α mRNA was inhibited by approximately 70% by propranolol or the β2-AR-specific inhibitor ICI 118,551. The exercise-induced increase in PGC-1α mRNA in β-less mice was also 36% lower than that in wild-type mice. These data indicate that up-regulation of PGC-1α expression in skeletal muscle by exercise is mediated, at least in part, by β-ARs activation. Among ARs, β2-AR may mediate an increase in PGC-1α by exercise.

scholarly journals Systemic β-Adrenergic Receptor Activation Augments the ex vivo Expansion and Anti-Tumor Activity of Vγ9Vδ2 T-Cells

2020 ◽  
Vol 10 ◽  
Author(s):  
Forrest L. Baker ◽  
Austin B. Bigley ◽  
Nadia H. Agha ◽  
Charles R. Pedlar ◽  
Daniel P. O'Connor ◽  
...  
Keyword(s):  
T Cells ◽  
Adrenergic Receptor ◽  
Ex Vivo ◽  
Receptor Activation ◽  
Ex Vivo Expansion ◽  
Vγ9vδ2 T Cells ◽  
Anti Tumor Activity

scholarly journals SAT0315 INHIBITION OF MICROSOMAL PROSTAGLANDIN E SYNTHASE-1 (MPGES-1) BY GS-248 REDUCES PROSTAGLANDIN E2 BIOSYNTHESIS WHILE INCREASING PROSTACYCLIN IN HUMAN SUBJECTS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1103.2-1103
Author(s):  
C. Edenius ◽  
G. Ekström ◽  
J. Kolmert ◽  
R. Morgenstern ◽  
P. Stenberg ◽  
...  
Keyword(s):  
Whole Blood ◽  
Vascular Tone ◽  
Ex Vivo ◽  
Prostaglandin E ◽  
Maximum Plasma ◽  
Prostaglandin E Synthase ◽  
Cox 2 ◽  
Anti Inflammatory ◽  
Oral Doses ◽  
Microsomal Prostaglandin E Synthase

Background:Microsomal prostaglandin E synthase-1 (mPGES-1) catalyzes the formation prostaglandin (PG) E2from cyclooxygenase derived PGH2(1, 2). Inhibition of mPGES-1 leads to reduction of pro-inflammatory PGE2, while in vessels there is a concomitant increase of vasoprotective prostacyclin (PGI2) via shunting of PGH2(3,4). Apart from relieving symptoms in experimental animal models of inflammation, inhibitors of mPGES-1 cause relaxation of human medium sized arteries(4)and resistance arteries(5). The prostaglandin profile following mPGES-1 inhibition, explains the anti-inflammatory effects and also opens for the possibility of treating inflammatory diseases with concomitant vasculopathies. GS-248 is a potent and selective inhibitor of mPGES-1 exhibiting sub-nanomolar IC50in human whole bloodex vivo.Objectives:To evaluate safety, tolerability, pharmacokinetics and pharmacodynamics of GS-248.Methods:Healthy males and females (age 18–73 years) were included in the study. Six cohorts were administrated single oral doses of 1-300mg GS-248 (n=36) or placebo (n=12), three cohorts were administered once daily doses of 20-180mg GS-248 (n=18) or placebo (n=12) over ten days. In addition, 8 subjects were treated in a separate cohort with 200mg celecoxib bid for ten days. Blood samples were drawn for measurement of GS-248 exposure and production of PGE2after LPS incubationex vivo. The content of PGE2and PGI2metabolites was measured in urine. All analyses were performed by LC-MS/MS.Results:GS-248 was safe and well tolerated at all tested dose levels. Maximum plasma concentration was achieved 1 - 2.5 hours after dosing, and half-life was about 10 hours. Induced PGE2formationex vivo,catalyzed by mPGES-1, was completely inhibited for 24 hours after a single low dose (40mg) of GS-248. In urine, GS-248 dose-dependently reduced the excretion of PGE2metabolite by more than 50% whereas the excretion of PGI2metabolite increased more than twice the baseline levels. In the celecoxib cohort urinary metabolites of both PGE2and PGI2were reduced with approx 50%.Conclusion:GS-248 at investigated oral doses was safe and well tolerated. There was a sustained inhibition of LPS induced PGE2formation in whole blood. In urine, there was a metabolite shift showing reduced PGE2and increased PGI2, while celecoxib reduced both PGE2and PGI2metabolites. This suggests that selective inhibition of mPGES-1 results in systemic shunting of PGH2to PGI2formation, leading to anti-inflammatory and vasodilatory effects, while preventing platelet activation. The results warrant further evaluation of GS-248 in inflammatory conditions with vasculopathies such as Digital Ulcers and Raynaud’s Phenomenon in Systemic Sclerosis.References:[1]Korotkova M, Jakobsson PJ. Persisting eicosanoid pathways in rheumatic diseases. Nat Rev Rheumatol. 2014;10:229-41[2]Bergqvist F, Morgenstern R, Jakobsson PJ. A review on mPGES-1 inhibitors: From preclinical studies to clinical applications. Prostaglandins Other Lipid Mediat. 2019;147:106383[3]Kirkby NS, et al. Mechanistic definition of the cardiovascular mPGES-1/COX-2/ADMA axis. Cardiovasc Res. 2020[4]Ozen G, et al. Inhibition of microsomal PGE synthase-1 reduces human vascular tone by increasing PGI2: a safer alternative to COX-2 inhibition. Br J Pharmacol. 2017;174:4087-98[5]Larsson K, et al. Biological characterization of new inhibitors of microsomal PGE synthase-1 in preclinical models of inflammation and vascular tone. Br J Pharmacol. 2019;176:4625-38Disclosure of Interests:Charlotte Edenius Shareholder of: Gesynta Pharma, Consultant of: Gesynta Pharma,, Gunilla Ekström Shareholder of: Gesynta Pharma, Consultant of: Gesynta Pharma,, Johan Kolmert Consultant of: Gesynta Pharma,, Ralf Morgenstern Shareholder of: Gesynta Pharma, Employee of: Gesynta Pharma, Patric Stenberg Shareholder of: Gesynta Pharma, Employee of: Gesynta Pharma, Per-Johan Jakobsson Shareholder of: Gesynta Pharma, Grant/research support from: Gesynta Pharma, AstraZeneca,, Göran Tornling Shareholder of: Gesynta Pharma, Vicore Pharma,, Consultant of: Gesynta Pharma, Vicore Pharma, AnaMar

scholarly journals NTPDase1 Modulates Smooth Muscle Contraction in Mice Bladder by Regulating Nucleotide Receptor Activation Distinctly in Male and Female

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 147
Author(s):  
Romuald Brice Babou Kammoe ◽  
Gilles Kauffenstein ◽  
Julie Pelletier ◽  
Bernard Robaye ◽  
Jean Sévigny
Keyword(s):  
Smooth Muscle ◽  
Ex Vivo ◽  
Smooth Muscle Contraction ◽  
Receptor Activation ◽  
Nucleoside Triphosphate ◽  
Nucleotide Receptors ◽  
Nerve Terminals ◽  
Wild Type ◽  
Nucleoside Triphosphate Diphosphohydrolase ◽  
Bladder Contraction

Nucleotides released by smooth muscle cells (SMCs) and by innervating nerve terminals activate specific P2 receptors and modulate bladder contraction. We hypothesized that cell surface enzymes regulate SMC contraction in mice bladder by controlling the concentration of nucleotides. We showed by immunohistochemistry, enzymatic histochemistry, and biochemical activities that nucleoside triphosphate diphosphohydrolase-1 (NTPDase1) and ecto-5′-nucleotidase were the major ectonucleotidases expressed by SMCs in the bladder. RT-qPCR revealed that, among the nucleotide receptors, there was higher expression of P2X1, P2Y1, and P2Y6 receptors. Ex vivo, nucleotides induced a more potent contraction of bladder strips isolated from NTPDase1 deficient (Entpd1−/−) mice compared to wild type controls. The strongest responses were obtained with uridine 5′-triphosphate (UTP) and uridine 5′-diphosphate (UDP), suggesting the involvement of P2Y6 receptors, which was confirmed with P2ry6−/− bladder strips. Interestingly, this response was reduced in female bladders. Our results also suggest the participation of P2X1, P2Y2 and/or P2Y4, and P2Y12 in these contractions. A reduced response to the thromboxane analogue U46619 was also observed in wild type, Entpd1−/−, and P2ry6−/− female bladders showing another difference due to sex. In summary, NTPDase1 modulates the activation of nucleotide receptors in mouse bladder SMCs, and contractions induced by P2Y6 receptor activation were weaker in female bladders.

scholarly journals Kisspeptin-8 Induces Anxiety-Like Behavior and Hypolocomotion by Activating the HPA Axis and Increasing GABA Release in the Nucleus Accumbens in Rats

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 112
Author(s):  
Katalin Eszter Ibos ◽  
Éva Bodnár ◽  
Zsolt Bagosi ◽  
Zsolt Bozsó ◽  
Gábor Tóth ◽  
...  
Keyword(s):  
Nucleus Accumbens ◽  
Ex Vivo ◽  
Gaba Release ◽  
Receptor Activation ◽  
Ambulatory Activity ◽  
Corticosterone Concentration ◽  
Reproductive Axis ◽  
Neuropeptide Ff ◽  
Serum Lh ◽  
Anxiogenic Effect

Kisspeptins (Kp) are RF-amide neuropeptide regulators of the reproductive axis that also influence anxiety, locomotion, and metabolism. We aimed to investigate the effects of intracerebroventricular Kp-8 (an N-terminally truncated octapeptide) treatment in Wistar rats. Elevated plus maze (EPM), computerized open field (OF), and marble burying (MB) tests were performed for the assessment of behavior. Serum LH and corticosterone levels were determined to assess kisspeptin1 receptor (Kiss1r) activation and hypothalamic-pituitary-adrenal axis (HPA) stimulation, respectively. GABA release from the nucleus accumbens (NAc) and dopamine release from the ventral tegmental area (VTA) and NAc were measured via ex vivo superfusion. Kp-8 decreased open arm time and entries in EPM, and also raised corticosterone concentration, pointing to an anxiogenic effect. Moreover, the decrease in arm entries in EPM, the delayed increase in immobility accompanied by reduced ambulatory activity in OF, and the reduction in interactions with marbles show that Kp-8 suppressed exploratory and spontaneous locomotion. The increase in GABA release from the NAc might be in the background of hypolocomotion by inhibiting the VTA-NAc dopaminergic circuitry. As Kp-8 raised LH concentration, it could activate Kiss1r and stimulate the reproductive axis. As Kiss1r is associated with hyperlocomotion, it is more likely that neuropeptide FF receptor activation is involved in the suppression of locomotor activity.

130 Burn Injury Reduces Bone Marrow Mesenchymal Stem Cells and Sensitizes Their Adrenergic Receptor Subgroups in a Murine Model

2021 ◽  
Vol 42 (Supplement_1) ◽  
pp. S87-S88
Author(s):  
Kuzhali Muthumalaiappan ◽  
Maria Camargo Johnson ◽  
Julia Walczak ◽  
Vimal Subramaniam ◽  
Anthony J Baldea ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Adrenergic Receptor ◽  
Burn Injury ◽  
Bone Marrow Cells ◽  
Ex Vivo ◽  
Traumatic Injury ◽  
Hematopoietic Cell ◽  
The Right

Abstract Introduction Previous burn and traumatic injury studies have established that adrenergic signaling is increased after burn injury and may lead to an impairment of hematopoietic cell development in the bone marrow (BM). Nonetheless, mesenchymal stem cells (MSCs), which have gained momentum in regenerative medicine also play a predominant role in the BM niche. Understanding the propensity of the adrenergic receptor (AR) response by MSCs can be utilized for devising targeted therapies. However, the traditional plastic adherence procedure using ex vivo culture of BM cells for several weeks may skew the actual characteristics of MSCs. Our current study focused on isolating MSCs from freshly obtained BM in a murine scald burn model with a goal to characterize the expression pattern of native AR subgroups present on BM MSCs as compared to sham mice. Methods Eight, two-month-old adult female mice were subjected to a 15% total body 3rd degree burn or sham burn. The mice were sacrificed 7 days later. Femurs were removed and total bone marrow cells were flushed out. Multi parametric flow cytometry was used to gate for cells negative for hematopoietic cell markers (CD45, CD11B) and positive for MSC markers (CD105, CD106, SSEA, Ly6A) and AR subgroups (α1, α2, β1, β2, β3). We measured the number of BM MSCs, quantified the subtypes of ARs present on MSCs, and compared the ratio of AR antibody binding per total MSC population. Results Overall the frequency of MSCs per million total BM cells decreased by 48% post-burn injury with165,300 ± 194 in sham versus 110,000 ± 30 in burn displayed as bar graph in Panel A. Over 90% of MSCs consistently express β2 AR and only 10% express α2 AR subgroup in both scald and sham burn. Presence of other subgroups ranged from 50% to 80% of MSCs as seen in histograms to the right of dotted line in Panel B. Our AR propensity score based on AR mean fluorescence intensity adjusted to total number of MSCs present was increased by 2.8-fold for α1, 2.5-fold for β1, 1.6-fold for β3, and 1.3-fold for β2 AR subgroups (Panel C). These findings indicate burn injury not only decreases the frequency of BM MSCs but also increases the affinity of certain AR subgroups present on MSCs. Since BM MSCs are the major source of cytokines, chemokines and growth factors; detailed studies on AR mediated signaling in BM MSCs is warranted. Conclusions Polarization of AR signaling in BM MSCs by burn-induced catecholamines may have broader implications for comorbidities such as bone resorption and muscle wasting observed in human patients post burn trauma.

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