MIPS521 is a positive allosteric modulator of adenosine A1 receptor (A1AR). MIPS521 also has a lower A1R allosteric affinity (pKB=4.95). MIPS521 exhibits pain-relieving effects in vivo[1][2].

MIPS521 (compound 13o) (3-10 μM) improves the ability of R-PIA to promote A1AR-mediated ERK1/2 phosphorylation[1].MIPS521 (0.3-30 μM; pretreament for 10 min, co-treatment for 30 min) produces a concentration-dependent potentiation of signalling by ADO in an inhibition of cAMP assay (expressed as a percentage of the inhibition of 3 μM forskolin-mediated cAMP) in CHO cells[2].

MIPS521 (1-30 μg in 10 μL; intrathecal administration) reverses mechanical hyperalgesia in rats, promoting robust antinociception[2].MIPS521 (10 μg in 10 μL; intrathecal administration) significantly reduces spontaneous pain in a conditioned place preference model[2].MIPS521 (1-30 μg in 10 μL; intrathecal administration) reduces eEPSCs in spinal cord from nerve-injured rats, with a pEC50 of 6.9. The maximum MIPS521-induced decrease in synaptic current amplitude is significantly greater in nerve-injured rats than in sham surgery controls[2].

[1]. Aurelio L, et, al. Allosteric modulators of the adenosine A1 receptor: synthesis and pharmacological evaluation of 4-substituted 2-amino-3-benzoylthiophenes. J Med Chem. 2009 Jul 23;52(14):4543-7. [2]. Draper-Joyce CJ, et, al. Positive allosteric mechanisms of adenosine A 1 receptor-mediated analgesia. Nature. 2021 Sep;597(7877):571-576.