GAL-021 is a large-conductance Ca2+-activated potassium channel (BKCa/KCa1.1) blocker.1 It inhibits BKCa single-channel activity in GH3 cells in a concentration-dependent manner when used at concentrations ranging from 1 to 10 μM. GAL-021 increases respiratory product minute volume in wild-type rats and mice (ED50s = 0.1 and 0.5 mg/kg) but not mice with bilaterally transected carotid sinus nerves or Slo-/- mice that lack the pore-forming α-subunit of BKCa. It reverses morphine-induced respiratory depression in rats and cynomolgus monkeys. GAL-021 also potentiates morphine-induced analgesia in a tail-flick assay in rats.
1.Golder, F.J., Dax, S.L., Baby, S.M., et al.Identification and characterization of GAL-021 as a novel breathing control modulatorAnesthesiology123(5)1093-1104(2015)