Adenosine administration by inhalation elicits concentration-related bronchoconstriction in subjects with asthma and chronic obstructive pulmonary disease (COPD). The mechanisms of adenosine-induced bronchoconstriction appear to involve a selective interaction with activated mast cells with subsequent release of preformed and newly-formed mediators. Further evidence linking adenosine signalling...

Adenosine has been reported to stimulate or inhibit the release of angiogenic factors depending on the cell type examined. To test the hypothesis that differential expression of adenosine receptor subtypes contributes to endothelial cell heterogeneity, we studied microvascular (HMEC-1) and umbilical vein (HUVEC) human endothelial cells. Based on mRNA level and stimulation of adenylate cyclase, ...

The "regulators of g-protein signalling" (RGS) comprise a large family of proteins that limit by virtue of their GTPase accelerating protein domain the signal transduction of G-protein coupled receptors. RGS proteins have been implicated in various neuropsychiatric diseases such as schizophrenia, drug abuse, depression and anxiety and aggressive behaviour. Since conditions associated with a lar...

The role of P1 receptors and P2Y1 receptors in coronary vasodilator responses to adenine nucleotides was examined in the isolated guinea pig heart. Bolus arterial injections of nucleotides were made in hearts perfused at constant pressure. Peak increase in flow was measured before and after addition of purinoceptor antagonists. Both the P1 receptor antagonist 8-(p-sulfophenyl)theophylline and a...

The striatum is the major input region of the basal ganglia, playing a pivotal role in the selection, initiation, and coordination of movement both physiologically and in pathophysiological situations such as Parkinson's disease. In the present study, we characterize interactions between NMDA receptors, adenosine receptors, and cAMP signaling within the striatum. Both NMDA (100 micrometer) and ...

Nonsynaptic release of ATP from electrically stimulated dorsal root gangion (DRG) axons inhibits Schwann cell (SC) proliferation and arrests SC development at the premyelinating stage, but the specific types of purinergic receptor(s) and intracellular signaling pathways involved in this form of neuron-glia communication are not known. Recent research shows that adenosine is a neuron-glial trans...

Nearly 90 years ago, Drury and Szent-Györgyi revealed that adenosine produced profound hypotension and bradycardia, and it affected kidney function in mammals [1]. [...].

lar AMPc in respiratory tissue were initially attributed to other mechanisms, it is currently accepted that the changes are due to the competitive antagonism of these bases with receptors of the neurotransmitter adenosine. Adenosine exerts a depressor effect with important repercussions in the functioning of the cardiovascular, renal, immune and central nervous systems. In recent years the sear...