Capadenoson

Capadenoson is a selective agonist of adenosine-A1 receptor. IC50 & Target: Adenosine A1 receptor^[1] In Vitro: To further elucidate the pharmacological properties of Capadenson, GTP shift assays are performed with the standard full A1-agonist CCPA and the A1-antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX). CCPA shows a K_i value of 4.2 nM in the binding assay on rat cortical brain membranes. In the presence of 1 mM GTP this K_i value shifts to a value of 64 nM. Therefore the GTP shift for CCPA is 15. DPCPX shows a GTP shift of 1 with virtually identical K_i values in the absence and presence of GTP. Capadenson shows a K_i value of 24 nM in the binding assay. In the presence of 1 mM GTP this K_i value shifts to a value of 116 nM resulting in a GTP shift of 5 for Capadenoson^[1]. In Vivo: In the in vivo experiments, Wistar rats and SHR are pre-treated with Capadenoson at a concentration of 0.15 mg/kg for 5 days. On day 5, a stress test (physical restraint) is performed for 2 hours. The plasma concentration of Capadenoson measured 3 hours after drug intake remains constant in the 5 days prior to the restraint stress test and averaged 7.63 µg/L on day 4 and 5, respectively^[1].