AR-M 1000390 is an effective selective δ-opioid receptor agonist with an EC50 of 7.2±0.9 nM.

AR-M 1000390 (Compound 6a) demonstrates binding affinities (IC 50) of 0.87±0.23 nM at the δ opioid receptor, while showing high selectivity against the µ receptor (IC 50 = 3800±172 nM) and the κ receptor (IC 50 = 7470±606 nM). In experimental studies, RINm5F cells treated with AR-M 1000390 (AR-M100390) and Cyclizine for 16-24 hours are assessed for both intracellular and secreted insulin levels. Exposure to AR-M 1000390 results in a dose-dependent reduction in insulin content, with a peak inhibition of approximately 90% observed at the highest concentration used (10 μM).

Groups of rats received doses of 5, 100, and 600 μmol/kg of AR-M 1000390 (AR-M100390) for durations of either 3 or 7 days, with an additional group administered 600 μmol/kg and observed for a recovery period of 14 days. Administration of AR-M 1000390 at 600 μmol/kg led to vacuolation in the β-cell of the rat pancreas, accompanied by insulin depletion and hyperglycemia after 7 days, similar to effects observed with cyclizine and cyproheptadine.