Description
Chromanol 293B is a blocker of slowly activating delayed-rectifier K
+ current (I
Ks) with an IC
50 value of 6.89 μM in
Xenopus oocytes expressing rat I
Ks channels. It is selective, having no activity at rat K
v1.1 or K
ir2.1 channels at a concentration of 30 μM. Chromanol 293B increases the rate and extent of I
Ks in guinea pig ventricular cells in a dose-dependent manner. It also inhibits cystic fibrosis transmembrane conductance regulator (CTFR) Cl
- currents (I
CTFR) with an IC
50 value of 19 μM in
Xenopus oocytes expressing human CTFR.
Uses
Chromanol 293B has been used in the inhibition of calcium and cyclic adenosine monophosphate (cAMP)-activated potassium channels in human epithelial cell lines. Chromanol 293B has been used in patch-clamp electrophysiology studies in cardiomyocytes.
Definition
ChEBI: Chromanol 293B is a 1-benzopyran.
General Description
Chromanol 293B enantiomer is a potent inhibitor of potassium channel protein (KvLQT1). In human atrial myocytes, chromanol 293B inhibits repolarization potassium currents. Chromanol 293B improves glucose-stimulated insulin secretion (GSIS) in pancreas by modulating potassium voltage-gated channel (KCNQ1).
Biological Activity
Blocker of the slow delayed rectifier K + current (I Ks ) (IC 50 = 1-10 μ M). Also blocks the CFTR chloride current (I CFTR ) (IC 50 = 19 μ M).
Biochem/physiol Actions
Blocker of the slow delayed rectifier K+ current via KCNQ1 channels
References
[1] H. SUESSBRICH. Specific blockade of slowly activating IsK channels by chromanols — impact on the role of IsK channels in epithelia[J]. FEBS Letters, 1996, 396 2-3: 271-275. DOI:
10.1016/0014-5793(96)01113-1[2] SUSUMU FUJISAWA Toshihiko I Kyoichi Ono. Time-dependent block of the slowly activating delayed rectifier K+ current by chromanol 293B in guinea-pig ventricular cells[J]. British Journal of Pharmacology, 2009, 129 5: 1007-1013. DOI:
10.1038/sj.bjp.0703126[3] A. BACHMANN U R U Quast. Chromanol 293B, a blocker of the slow delayed rectifier K+ current (IKs), inhibits the CFTR Cl– current[J]. Naunyn-Schmiedeberg’s archives of pharmacology, 2001, 363 1: 590-596. DOI:
10.1007/s002100100410
