Adenosine is released during tissue injury, ischemia and tumor growth, and promotes angiogenesis. Because mast cells accumulate in the proximity of new blood vessel development, we examined if they may contribute to adenosine-induced angiogenesis. We found that HMC-1 human mast cells express A2A, A2B, and A3 adenosine receptors. The ...

?(2)-adrenoceptors are known to mediate gastroprotective effect in both acid-dependent and acid-independent ulcer models. The aim of the present study was to determine, which of the three ?(2)-adrenoceptor subtypes (?(2A), ?(2B) or ?(2C)) is responsible for this protection. Various ?(2)-adrenoceptor agonists and ...

Studies show that kidneys produce 2',3'-cAMP, 2',3'-cAMP is exported and metabolized to 2'-AMP and 3'-AMP, 2'-AMP and 3'-AMP are metabolized to adenosine, 2',3'-cAMP inhibits proliferation of preglomerular vascular smooth muscle cells (PGVSMCs) and glomerular mesangial cells (GMCs), and A(2B) (not A(1), A(2A), or A(3)) adenosine receptors mediate part of the antiproliferative ...

Adenosine clearly regulates coronary blood flow (CBF); however, contributions of specific adenosine receptor (AR) subtypes (A(1), A(2A), A(2B), A(3)) to CBF in swine have not been determined. ARs generally decrease (A(1), A(3)) or increase (A(2A), A(2B)) cyclic adenosine ...

... Title : Regulation of Agonist - and Antagonist - Mediated Activation of Human Progesterone Receptors by Phosphorylation. ...

Effects of some selective 5-HT antagonists on methamphetamine-induced locomotor activity were investigated in male mice in order to study whether this effect of methamphetamine is selectively or at least partially, induced through stimulation of a specific serotonin receptor subtype. Methamphetamine (1.5 mg/kg, IP) produced a significant increase in locomotor activity. ...

Although adenosine has been implicated in penile erection in human males, the receptor subtype responsible for adenosine regulation of human corpus cavernosum (HCC) smooth muscle tone is still a matter of debate. Using selective adenosine agonists and antagonists, we aimed at characterizing the adenosine receptors mediating relaxation of precontracted ...

It has recently been shown that clonidine suppresses itch-related responses via its action on ?(2)-adrenoceptors in the spinal cord, raising the possibility that the descending noradrenergic system regulates itch signaling in the spinal cord. In this study, we investigated whether the transmission of itch signals in�the spinal cord is under tonic inhibition by the descending noradrenergic ...

This study tested the hypothesis that adenosine, in murine corpora cavernosa, produces direct relaxation of smooth muscle cells and inhibition of contractile responses mediated by sympathetic nerve stimulation. Penes were excised from anesthetized male C57BL/6 mice, dissected, and cavernosal strips were mounted to record isometric force. Adenosine, 2-chloroadenosine (stable ...

Cell models of ischemic preconditioning (IPC) indicate nitric oxide (NO) is involved in protection accruing during reoxygenation but disagree whether it acts through PKG. Using a more relevant intact heart model, we studied isolated rabbit hearts subjected to 30-min coronary artery occlusion/120-min reperfusion. We previously found protection from PKG activator 8-(4-chlorophenylthio)-guanosine ...

Adenosine is a ubiquitous signaling molecule whose physiological functions are mediated by its interaction with four G-protein-coupled receptor subtypes, termed A(1), A(2A), A(2B) and A(3). As a result of increased metabolic rates, this nucleoside is released from a variety of cells throughout the body in ...

... Title : Regulation of Agonist- and Antagonist-Mediated Activation of Human Progesterone Receptors by Phosphorylation. ...

Adenosine is an important cerebral vasodilator, but mediating mechanisms are not understood. We investigated the expression of adenosine receptor subtypes in isolated cerebral arterial muscle cells (CAMCs), and their role in adenosine-induced superoxide (O(2)(-)) generation and reduction in cerebral arterial tone. Reverse transcriptase-PCR, western blotting, and ...

Methotrexate (MTX) is widely utilized for the treatment of patients with rheumatoid arthritis (RA); however, recent observation of the MTX-resistant patients proposed some difficulty in MTX-dependent therapeutic approach for RA. To access cellular events related to MTX resistance in RA in respect to inflammatory bone destruction, we investigated on an involvement of the potent inflammatory ...

Fragile X associated tremor ataxia syndrome (FXTAS) is a recently described neurodegenerative disorder of older adult carriers of premutation alleles (60-200 CGG repeats) in the fragile-X mental retardation gene (FMR1). It has been proposed that FXTAS is an RNA mediated neurodegenerative disease caused by the titration of RNA binding proteins by the CGG repeats. To test this ...

Rationale: Adenosine induces airways obstruction in asthmatic subjects but the receptor subtype responsible remains unknown. Objectives: To determine the pharmacological profile of adenosine receptor subtypes mediating contraction and to investigate the mechanism in normal and passively sensitized human airway tissues. Methods: Contraction of bronchial rings isolated from ...

All four adenosine receptor subtypes have been shown to play a role in cardioprotection, and there is evidence that all four subtypes may be expressed in cardiomyocytes. There is also increasing evidence that optimal adenosine cardioprotection requires activation of more than one receptor subtype. The purpose of this study was to determine whether adenosine A(2A) and/or ...

The antagonistic interaction between adenosine and dopamine receptors could have important pathophysiological and therapeutic implications in Parkinson's disease (PD). The primary aim of this study was to investigate the expression, affinity, and density of A(1), A(2A), A(2B), and A(3) adenosine receptors (ARs) and ...

The process of alternative splicing is widely misregulated in cancer, but the contribution of splicing regulators to cancer development is largely unknown. In this study, we found that the splicing factor hnRNP A2/B1 is overexpressed in glioblastomas and is correlated with poor prognosis. Conversely, patients who harbor deletions of ...

... ER expression and attain hormone un- responsiveness ... ER antagonists, such as tamoxifen, have a ... Antagonist- mediated inhibition of ER not only is ...

Extracellular ATP and ADP have been shown to exhibit potent angiogenic effects on pulmonary artery adventitial vasa vasorum endothelial cells (VVEC). However, the molecular signaling mechanisms of extracellular nucleotide-mediated angiogenesis remain not fully elucidated. Since elevation of intracellular Ca(2+) concentration ([Ca(2+)](i)) is required for cell proliferation and ...

... Title : Regulation of Agonist--and Antagonist--Mediated Activation of Human Progesterone Receptors by Phosphorylation. ...

molecule adenosine. In mammals, adenosine assumes an essential role in regulating innate and acquired, but only adenosine is able to completely suppress immune responses (N�meth et al., 2006). The immunoregulatory attributes of adenosine are mediated via four transmembrane adenosine receptors: A1, A2A, A2B

A new series of 2,6,9-trisubstituted adenines (5-14) have been prepared and evaluated in radioligand binding studies for their affinity at the human A(1), A(2A) and A(3) adenosine receptors and in adenylyl cyclase experiments for their potency at the human A(2B) subtype. From this preliminary study the conclusion can be drawn that ...

Cell death caused by the accumulation of extracellular adenosine is believed to contribute to the profound loss of T lymphocytes in patients with severe combined immunodeficiency disease due to adenosine deaminase deficiency. Although adenosine is known to trigger apoptosis in thymocytes and peripheral T cells, the molecular basis of this effect is not understood. In this study, we show that ...

Human erythrocytes have been regarded as perfect osmometers, which swell or shrink as dictated by their osmotic environment. In contrast, in most other cells, swelling elicits a regulatory volume decrease (RVD) modulated by the activation of purinic and pyrimidinic receptors (P receptors). For human erythrocytes this modulation has not been tested, and we thus investigated whether P receptor ...

Trafficking of mRNA molecules from the nucleus to distal processes in neural cells is mediated by hnRNP A2/B1 trans-acting factors. Although hnRNP A2/B1 is alternatively spliced to generate 4 isoforms, most functional studies have not distinguished ...

BACKGROUND: Adenosine has been shown to inhibit cell growth and induce apoptosis in the several cancer cells via intrinsic and extrinsic pathway. The present study was designed to understand the mechanism underlying adenosine-induced apoptosis in the DU-145, PC3, and LNcap-FGC10 human prostate cancer cells. METHODS: To observe cell viability and proliferation, MTT assay, cell counting, and BrdU ...

Adenosine accumulates to high levels in inflamed or ischemic tissues and activates A3 adenosine receptors (ARs) on mast cells to trigger degranulation. Here we show that stimulation of rat basophilic leukemia (RBL)-2H3 mast-like cells with the A3 AR agonists N6-(3-iodo)benzyl-5'-N-methylcarboxamidodoadenosine (IB-MECA; 10 nM) or inosine (10 microM) stimulates phosphorylation of protein kinase B ...

The primary aim of this study was to investigate adenosine receptors (ARs) in bronchoalveolar lavage (BAL) macrophages from patients with chronic obstructive pulmonary disease (COPD) and age-matched healthy smokers. A(2B)ARs were significantly decreased in BAL macrophages from patients with COPD when compared with healthy smokers. The ...

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder associated with fragile X premutation carriers. Previous studies have shown that fragile X rCGG repeats are sufficient to cause neurodegeneration and that the rCGG repeat-binding proteins Pur ? and hnRNP A2/B1 could modulate ...

Importance of making available selective adenosine receptor antagonists is boosted by recent findings of adenosine involvement in many CNS dysfunctions. In the present work a series of 8-bromo-9-alkyl adenines are prepared and fully characterized in radioligand binding assays or functional cyclase experiments in respect to their interaction with all the four adenosine receptor ...

Purines are important modulators of bone cell biology. ATP is metabolized into adenosine by human primary osteoblast cells (HPOC); due to very low activity of adenosine deaminase, the nucleoside is the end product of the ecto-nucleotidase cascade. We, therefore, investigated the expression and function of adenosine receptor subtypes (A(1) , A(2A) , ...

1-Propyl- and 1,3-dimethyl-8-p-sulfophenylxanthine (PSB-1115 and SPT) were used as starting compounds for the development of adenosine A(2B) receptor antagonists with a sulfonamide structure. Since standard reactions for sulfonamide formation failed or resulted in very low yields, we developed a new method for the ...

Mucociliary clearance, vital to lung clearance, is dependent on cilia beat frequency (CBF), coordination of cilia, and the maintenance of periciliary fluid. Adenosine, the metabolic breakdown product of ATP, is an important modulator of ciliary motility. However, the contributions of specific adenosine receptors to key airway ciliary motility processes are unclear. We hypothesized that adenosine ...

Hepatitis C virus (HCV) is a common infectious agent and may induce several systemic disorders like mixed cryoglobulinemia. In the geographic areas where HCV infection is hyperendemic, HCV is the predominant etiologic factor for porphyria cutanea tarda and lichen planus. Vasculitides and autoimmune disorders, such as sicca syndrome, are probably often related to the virus. ...

Adenosine is an important paracrine agent regulating renal vascular tone via adenosine A(1) and A(2) receptors. While A(2B) receptor message and protein have been localized to preglomerular vessels, functional evidence on the role of A(2B) receptors in mediating the vasodilator action of adenosine on afferent ...

Serotonin [5-hydroxytryptamine (5-HT)]-mediated cardiac valvular disease has been commonly observed in patients with carcinoid tumors. Previous research by others using reverse transcriptase-polymerase chain reaction demonstrated that aortic valve cells expressed predominantly 5-HT(2A/2B) receptors (5-HT(2A)R). ...

The present study has investigated the preliminary pharmacological profile of the receptors mediating vasoconstriction to 5-hydroxytryptamine (5-HT) in the internal carotid bed of vagosympathectomised dogs.One minute intracarotid infusions of the agonists 5-HT (0.1�10??g?min^?1), sumatriptan (0.3�10??g?min^?1; ...

In the kidney, defects in the regulation of urine salt excretion can result in extracellular fluid volume expansion, leading to salt-sensitive hypertension. Previous studies have demonstrated that when rats are maintained on a high sodium chloride (NaCl) diet, adenosine production increases in the renal medulla with parallel changes in adenosine receptor expression. These studies suggest that ...

Background:Adenosine mediates its actions through four G protein-coupled receptors, A1, A2a, A2b and A3. The A1 receptor (A1R) is dominant in adipocytes where it mediates many actions that include inhibition of lipolysis, stimulation of leptin secretion and protection against obesity-related ...

Jun 16, 2011 � We are investigating the potential of antagonistic bacteria, isothiocyanates, and mycophagous amoebae to control diseases caused by ...

... Descriptors : *CNS depressants, *Central nervous system, Brain, Inhibition, Physiology, Pharmacology, Amino acids, Glycine, Penicillins, Drugs ...

Background and purpose. This study was undertaken to investigate the role of adenosine in the modulation of the contractility in mouse duodenum and to characterize the adenosine receptor subtypes involved. Experimental approach. RT-PCR was used to investigate the expression of mRNA encoding for A(1) , A(2A) , A(2B) and A(3) receptors. ...

, M, in [a, 2 (b)]. By hypothesis, this maximum must occur in (a, 2 (b)). Choose c = max{e (a, 2 (b of this paper assume = ((a), (a)) � ((2 (b)), ...

The formation of adenosine dampens inflammation by inhibiting most cells of the immune system. Among its actions on neutrophils, adenosine suppresses superoxide generation and regulates chemotactic activity. To date, most evidence implicates the G(s) protein-coupled A(2A) adenosine receptor (AR) as the primary AR subtype responsible for mediating the actions of adenosine on ...

Human mast cells express functional A(2A) and A(2B) adenosine receptors. However, only stimulation of A(2B), not A(2A), leads to secretion of interleukin (IL)-4, an important step in adenosine receptor-mediated induction of IgE synthesis by B-cells. In this study, we investigate intracellular pathways that link stimulation of A(2B) receptors to IL-4 up-regulation in HMC-1 mast ...

CD73 is a GPI-anchored cell surface protein with ecto-5'-nucleotidase enzyme activity that plays a crucial role in adenosine production. While the roles of adenosine receptors (AR) on osteoblasts and osteoclasts have been unveiled to some extent, the roles of CD73 and CD73-generated adenosine in bone tissue are largely unknown. To address this issue, we first analyzed the bone phenotype of ...

mediators. Some histamine H1 receptor antagonists exert anti- inflammatory activities by modulating mediator receptor antagonist, on the release of eicosanoids, histamine and IL-4 from human basophils and lung mast release from lung mast cells. In contrast, mizolastine enhanced up to 80% IgE- ...

Few signaling molecules have the potential to influence the developing mammal as the nucleoside adenosine. Adenosine levels increase rapidly with tissue hypoxia and inflammation. Adenosine antagonists include the methylxanthines caffeine and theophylline. The receptors that transduce adenosine action are the A1, A2a, ...

Dose-response comparisons of the ability of the selective delta antagonist ICI 154, 129 (12.5-50 nmol), the nonselective antagonist naloxone (29-290 nmol), and the irreversible selective u antagonist B-fNA (1.3-21 nmol) to alter the threshold response to ...

Erythrocyte invasion by Plasmodium merozoites is a complex, multistep process that is mediated by a number of parasite ligand-erythrocyte receptor interactions. One such family of parasite ligands includes the P. falciparum reticulocyte binding homologue (PfRH) proteins that are homologous with the P. vivax reticulocyte binding proteins and have been shown to play a role in ...

The adenosine A(2B) receptor is of considerable interest as a new drug target for the treatment of asthma, inflammatory diseases, pain, and cancer. In the present study we investigated the role of the cysteine residues in the extracellular loop 2 (ECL2) of the receptor, which is particularly cysteine-rich, by a combination of ...

Matrix metalloproteinases are major mediators of tissue destruction in various chronic inflammatory disorders. The present invention demonstrates that over-expression of intracellular isoform of IL-1 receptor antagonist confers to recipient cells resistan...

BACKGROUND AND PURPOSE Adenosine is believed to participate in the pathological development of asthma through a mast cell-dependent mechanism. Our study aimed to pharmacologically characterize the functions of adenosine receptor (AR) subtypes (A(1) , A(2A) , A(2B) and A(3) ) in primary human cultured mast cells (HCMC). EXPERIMENTAL ...

Calmodulin (CaM) antagonists have been shown to inhibit tumor cell invasion and metastasis and to induce apoptosis in various tumor models, but the molecular mechanism of CaM antagonist-mediated apoptosis is poorly understood. Here, we demonstrate that interferon (IFN)-gamma induces susceptibility to CaM antagonist-mediated apoptosis ...

1. The present study was designed to characterize the adenosine receptors involved in the relaxation of the pig intravesical ureter, and to investigate the action of adenosine on the non adrenergic non cholinergic (NANC) excitatory ureteral neurotransmission. 2. In U46619 (10(-7) M)-contracted strips treated with the adenosine uptake inhibitor, nitrobenzylthioinosine (NBTI, 10(-6) M), adenosine ...

Index of /pub/Mission_Archives/sts/STS-106 - 2A.2 b/EC's_FREEZE. [ICO], Name � Last modified � Size � Description. [DIR], Parent Directory, - ...

Country-Level GDP and Downscaled Projections Based on the SRES A1, A2, B1, and B2 Marker Scenarios, 1990-2100 [CIESIN_SEDAC_CGDP_A1A2B1B2] ...