Editing Adenosine (section)

=== Adenosine receptors ===
{{Main|Adenosine receptor}}
All adenosine receptor subtypes (A<sub>1</sub>, A<sub>2A</sub>, A<sub>2B</sub>, and A<sub>3</sub>) are [[G-protein-coupled receptors]]. The four receptor subtypes are further classified based on their ability to either stimulate or inhibit [[adenylate cyclase]] activity. The A<sub>1</sub> receptors couple to G<sub>i/o</sub> and decrease cAMP levels, while the A<sub>2</sub> adenosine receptors couple to G<sub>s</sub>, which stimulates adenylate cyclase activity. In addition, A<sub>1</sub> receptors couple to G<sub>o</sub>, which has been reported to mediate adenosine inhibition of Ca<sup>2+</sup> conductance, whereas A<sub>2B</sub> and A<sub>3</sub> receptors also couple to G<sub>q</sub> and stimulate [[phospholipase]] activity.
Researchers at Cornell University have recently shown adenosine receptors to be key in opening the blood-brain barrier (BBB).
Mice dosed with adenosine have shown increased transport across the BBB of amyloid plaque antibodies and prodrugs associated with Parkinson's disease, Alzheimer's, multiple sclerosis, and cancers of the central nervous system.<ref>{{Cite journal | vauthors = Carman AJ, Mills JH, Krenz A, Kim DG, Bynoe MS | title = Adenosine receptor signaling modulates permeability of the blood-brain barrier | journal = The Journal of Neuroscience | volume = 31 | issue = 37 | pages = 13272–13280 | date = September 2011 | pmid = 21917810 | pmc = 3328085 | doi = 10.1523/JNEUROSCI.3337-11.2011 }}</ref>