Adenosine is a prototypical neuromodulator, which mainly controls excitatory transmission through the activation of widespread inhibitory A1 receptors and synaptically located A2A receptors. It was long thought that the predominant A1 receptor-meditated modulation by endogenous adenosine was a homeostatic process intrinsic to the synapse. New studies indicate that endogenous extracellular adeno...

Extracellular adenosine has a key role in the development and function of the cells of the immune system. Many of the adenosine actions seem to be mediated by specific surface receptors positively coupled to adenylate cyclase: A2A and A2B. Despite the fact that A2A receptors (A2ARs) can be easily studied due to the availability of the specific agonist CGS21680, a pharmacological and physiologic...

Adenosine has many of the characteristics of a regulator of cerebral blood flow and adenosine receptors change in morphine dependency. In this study the changes in adenosine receptors' responsiveness of pial vessels in the hind limb area of the sensory cortex were evaluated in morphine dependent rats (MDR) using the laser Doppler flowmetry technique. Adult male Sprague Dawley rats (250-350 ...

Morphine treatment of rats (60-70 mg/kg/day, 7 days) reduced delta opioid receptor-mediated inhibition of adenylyl cyclase activity in caudate putamen without any change in regulation by mu receptors. Earlier studies suggested that dopamine D1 and mu opioid receptors that regulate adenylyl cyclase are expressed preferentially by striato-nigral neurons, whereas adenosine A2a and delta1 opioid re...

Neurology 2012;79:616–618 Caffeine, the world’s most widely used psychomotor stimulant, potentiates the antiparkinsonian effects of levodopa in preclinical models, as noted nearly 40 years ago.1 The findings prompted early placebo-controlled crossover studies of caffeine as an adjunct to levodopa or a dopamine agonist in Parkinson disease (PD).2,3 No motor effect of caffeine was demonstrated ot...

Adenosine acts as neuromodulator in the brain, which its involvement in a wide range of brain processes and diseases has been studied, such as epilepsy, sleep, anxiety, panic disorder, Alzheimer’s disease, Parkinson’s disease and schizophrenia. Adenosine receptors have been detected: A1R, A2AR (A2AR), A2BR, and A3R. A1R and A2R inhibit cAMP production, while A2AR and A2BR stimulate cAMP product...

A2A adenosine receptors (A2A-ARs) are known modulators of renal hemodynamics and potent inhibitors of inflammation. We sought to determine whether selective activation of A2A-ARs protects kidneys from ischemia-reperfusion injury. The ester derivative of DWH-146 (DWH-146e), a selective A2A agonist, was found to be more potent and selective for A2A-ARs than the prototype compound CGS-21680. Osmot...

We proposed [11C]KF18446 as a selective radioligand for mapping the adenosine A2A receptors being highly enriched in the striatum by positron emission tomography (PET). In the present study, we investigated whether [11C]KF18446 PET can detect the change in the striatal adenosine A2A receptors in the rat after unilateral injection of an excitotoxin quinolinic acid into the striatum, a Huntington...

adenosine has many of the characteristics of a regulator of cerebral blood flow and adenosine receptors change in morphine dependency. in this study the changes in adenosine receptors' responsiveness of pial vessels in the hind limb area of the sensory cortex were evaluated in morphine dependent rats (mdr) using the laser doppler flowmetry technique. adult male sprague dawley rats (250-350...