The adenosine A2A receptor is a G-protein-coupled receptor (GPCR) that has been extensively studied during the past few decades because it offers numerous possibilities for therapeutic applications. Herein we describe adenosine A2A receptor distribution, signaling pathways, pharmacology, and molecular structure, followed by a summary and SAR discussion of the most relevant series of adenosine A...

The main purpose of this investigation was to evaluate whether the cyclic AMP-adenosine pathway, ie, the conversion of cAMP to AMP and, hence, to adenosine, is involved in the regulation of nitric oxide (NO) synthesis by vascular smooth muscle cells (SMCs). Treatment of confluent monolayers of SMCs with adenosine, 2-chloroadenosine (stable analog of adenosine), and agents that elevate endogenou...

The 'omnipresence' of adenosine in all nervous system cells (neurons and glia) together with the intensive release of adenosine following insults, makes adenosine as a sort of 'maestro' of synapses leading to the homeostatic coordination of brain function. Besides direct actions of adenosine on the neurosecretory mechanisms, where adenosine operates to tune neurotransmitter release, receptor-re...

The molecular vibration-activity relationship in the receptor-ligand interaction of adenosine receptors was investigated by structure similarity, molecular vibration, and hierarchical clustering in a dataset of 46 ligands of adenosine receptors. The resulting dendrogram was compared with those of another kind of fingerprint or descriptor. The dendrogram result produced by corralled intensity of...

For decades, it has been thought that adenosine is exclusively antimitogenic on vascular smooth muscles via the A2-type adenosine receptor. Recently, we have demonstrated that adenosine stimulates proliferation of porcine coronary artery smooth muscle cells (CASMC) through the A1 adenosine receptor. However, the cell-signaling mechanisms underlying A1 receptor-mediated CASMC proliferation in re...

In the present study, we sought to evaluate whether the antiadrenergic action of adenosine in the heart is altered in pressure overload hypertrophy produced in rats by suprarenal aortic banding. Epicardial and coronary effluent adenosine and inosine concentrations and release were significantly elevated in compensated pressure overload hypertrophy but not in hearts with left ventricular failure...

Prior studies indicate that adenosine and the adenosine A2A receptor play a role in hepatic fibrosis by a mechanism that has been proposed to involve direct stimulation of hepatic stellate cells (HSCs). The objective of this study was to determine whether primary hepatic stellate cells produce collagen in response to adenosine (via activation of adenosine A2A receptors) and to further determine...

UNLABELLED Adenosine and adenosine analogs induce analgesia in humans and presumed antinociception in animal models when administered both systemically and intrathecally. In the present investigation in rats, we studied the effects of intrathecally administered adenosine analogs, with or without systemic coadministration of an adenosine antagonist (theophylline), on substance P (SP) and calcito...

Adenosine Ri receptors and inhibitory guanine-nucleotide-regulatory components were solubilized from rat cerebral-cortical membranes with sodium cholate. (-)-N6-Phenylisopropyl[2,8-3H]adenosine [( 3H]PIA) binds with high affinity to the soluble receptors, which retain the pharmacological specificity of adenosine Ri receptors observed in membranes. The binding is regulated by bivalent cations an...