Related Experiment Video
Updated: Jun 12, 2026

Measuring Uptake of the Glucose Analog, 6-(N-(7-Nitrobenz-2-Oxa-1,3-Diazol-4-yl)Amino)-6-Deoxyglucose, in Intact Murine Neural Retina
Published on: March 14, 2025
[(3)H]Glycogen hydrolysis elicited by adenosine in rabbit retina: involvement of A(2)-receptors
1Nuffield Laboratory of Ophthalmology, University of Oxford, Walton Street, Oxford OX2 6AW, England.
Abstract:
Adenosine promotes a concentration-dependent hydrolysis of [(3)H]glycogen newly synthesised from [(3)H]glucose by rabbit retinal slices. The EC(50) is 15 ?M. Theophylline and 8-phenyltheophylline antagonise the glycogenolysis induced by adenosine. The rank order of efficacy of adenosine agonists is chloroadenosine (CLA) and adenosine > d - phenylisopropyl - adenosine ( d - PIA ) > l - PIA > N- ethyl - carboxamidoadenosine ( NECA ) > cyclohexyladenosine (CHA), suggesting that adenosine promotes glycogenolysis via receptors of the A(2) type. This is supported by the finding that the rank order of effectiveness of adenosine agonists for stimulating C-AMP production is similar to that found for glycogenolysis though NECA is more efficacious than d-PIA and l-PIA. In addition, the weak stereospecificity observed for the glycogenolytic action d-PIA and l-PIA provides further support. It is suggested that some A(2)-receptors exist on Müller cells of the retina and that adenosine has a modulatory role in the retina, coupling neuronal activity and energy metabolism in the Müller cells.
Related Concept Videos
cAMP-dependent Protein Kinase Pathways
Adrenergic Receptors: β Subtype
Isoprenaline > Adrenaline > Noradrenaline
Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes.
β1-adrenoceptors: β1-adrenoceptors have equal affinities for...
GPCRs Regulate Adenylyl Cylase Activity
Two...
Adrenergic Receptors: ɑ Subtype
Adrenaline ≥ Noradrenaline >> Isoprenaline
α-adrenoceptors are further divided into α1 and α2-adrenoceptors.
α1-Adrenoceptors: These receptors are located postsynaptically on the effector organs and cause constriction of smooth muscle mediated by activation of phospholipase C—inositol-1,4,5-trisphosphate...
Adrenergic Receptors (Adrenoceptors): Classification
α-Adrenoceptors
α-Adrenoceptors are classified into two main subtypes: α1 and α2. The α1 adrenoceptors, which are found on postsynaptic...
G-Protein Gated Ion Channels
Sensory organs,...

