A3 adenosine receptor actions of a nominally A1 receptor selective agonist
Anwesha Ghosh, Leonor Ribeiro-Rodrigues, Gabriele Ruffolo, Veronica Alfano, Nádia Rei, Dilip K Tosh, Joaquim A Ribeiro, Eleonora Palma, Kenneth A Jacobson, Ana M Sebastião · FENS Forum 2024
Adenosine, through the A1 receptor (A1R), is an endogenous anticonvulsant. Development of adenosine receptor agonists as antiseizure drugs has been hampered by cardiac effects. A moderately A1R-selective agonist, MRS5474, has been reported to suppress seizures without appreciable cardiac action (Tosh et al., 2012, J Med Chem, 55:8075). We aimed at understanding its mechanism of action. MRS5474 (50-500nM) was devoid of effect upon rodent excitatory synaptic signals in hippocampal slices, except when hyperexcitability was previously induced in vivo or ex vivo. This contrasted with the effect of