Biological Activity |
Tertiapin-Q is a highly selective blocker of GIRK1/4 heterodimer and ROMK1 (Kir1.1). IC50 & Target: Potassium channel[1] In Vitro: Tertiapin-Q is a highly selective blocker of G protein-coupled inwardly rectifying potassium (GIRK1/4) heterodimer and renal outer medullary potassium channel (ROMK1, Kir1.1)[1]. Tertiapin-Q is a potent and selective blocker for Kir1.1 renal outer medullary potassium, Kir3.1-Kir3.4 channels and calcium activated large conductance potassium channels (big potassium channels). The somatostatin (SS-14)-activated current is almost completely blocked (93.2+/-2.9%, n=5; P<0.01) by preincubation with the G protein-coupled inwardly rectifying potassium (GIRK) channel blocker Tertiapin-Q (TPN-Q)[2]. In Vivo: Tertiapin-Q is a muscarinic acetylcholine receptor-operated K+ current (IK, Ach) blocker. After the cessation of rapid atrial pacing, the atrial effective refractory period (AERP) is unchanged during the experimental period in the rapid atrial pacing (RAP) rabbits (n=6). Bepridil (1 mg/kg, n=5 for each group), Amiodarone (10 mg/kg, n=5 for each group), Vernakalant (3 mg/kg, n=5 for each group), Ranolazine (10 mg/kg, n=6 for each group) or Tertiapin-Q (0.03 mg/kg, n=5 for each group) on the AERP in the control and RAP rabbits. Tertiapin-Q significantly prolongs the AERP at each pacing cycle length both in the control and RAP rabbits. The extents of prolonging effect of Tertiapin-Q on the AERP in the RAP rabbits are greater than those in the control animals[3]. |