TY - JOUR
T1 - The small molecule NS11021 is a potent and specific activator of Ca2+-activated big-conductance K+ channels.
AU - Bentzen, Bo Hjorth
AU - Nardi, Antonio
AU - Calloe, Kirstine
AU - Madsen, Lars Siim
AU - Olesen, Søren-Peter
AU - Grunnet, Morten
N1 - Keywords: Animals; Calcium; Cell Line; Guinea Pigs; Humans; Large-Conductance Calcium-Activated Potassium Channel alpha Subunits; Mice; Mice, Knockout; Mitochondria; Tetrazoles; Thiourea; Xenopus laevis
PY - 2007
Y1 - 2007
N2 - Large-conductance Ca(2+)- and voltage-activated K(+) channels (Kca1.1/BK/MaxiK) are widely expressed ion channels. They provide a Ca(2+)-dependent feedback mechanism for the regulation of various body functions such as blood flow, neurotransmitter release, uresis, and immunity. In addition, a mitochondrial K(+) channel with KCa1.1-resembling properties has been found in the heart, where it may be involved in regulation of energy consumption. In the present study, the effect of a novel NeuroSearch compound, 1-(3,5-bis-trifluoromethyl-phenyl)-3-[4-bromo-2-(1H-tetrazol-5-yl)-phenyl]-thiourea (NS11021), was investigated on cloned KCa1.1 expressed in Xenopus laevis oocytes and mammalian cells using electrophysiological methods. NS11021 at concentrations above 0.3 microM activated KCa1.1 in a concentration-dependent manner by parallel-shifting the channel activation curves to more negative potentials. Single-channel analysis revealed that NS11021 increased the open probability of the channel by altering gating kinetics without affecting the single-channel conductance. NS11021 (10 microM) influenced neither a number of cloned Kv channels nor endogenous Na(+) and Ca(2+) channels (L- and T-type) in guinea pig cardiac myocytes. In conclusion, NS11021 is a novel KCa1.1 channel activator with better specificity and a 10 times higher potency compared with the most broadly applied KCa1.1 opener, NS1619. Thus, NS11021 might be a valuable tool compound when addressing the physiological and pathophysiological roles of KCa1.1 channels.
AB - Large-conductance Ca(2+)- and voltage-activated K(+) channels (Kca1.1/BK/MaxiK) are widely expressed ion channels. They provide a Ca(2+)-dependent feedback mechanism for the regulation of various body functions such as blood flow, neurotransmitter release, uresis, and immunity. In addition, a mitochondrial K(+) channel with KCa1.1-resembling properties has been found in the heart, where it may be involved in regulation of energy consumption. In the present study, the effect of a novel NeuroSearch compound, 1-(3,5-bis-trifluoromethyl-phenyl)-3-[4-bromo-2-(1H-tetrazol-5-yl)-phenyl]-thiourea (NS11021), was investigated on cloned KCa1.1 expressed in Xenopus laevis oocytes and mammalian cells using electrophysiological methods. NS11021 at concentrations above 0.3 microM activated KCa1.1 in a concentration-dependent manner by parallel-shifting the channel activation curves to more negative potentials. Single-channel analysis revealed that NS11021 increased the open probability of the channel by altering gating kinetics without affecting the single-channel conductance. NS11021 (10 microM) influenced neither a number of cloned Kv channels nor endogenous Na(+) and Ca(2+) channels (L- and T-type) in guinea pig cardiac myocytes. In conclusion, NS11021 is a novel KCa1.1 channel activator with better specificity and a 10 times higher potency compared with the most broadly applied KCa1.1 opener, NS1619. Thus, NS11021 might be a valuable tool compound when addressing the physiological and pathophysiological roles of KCa1.1 channels.
U2 - 10.1124/mol.107.038331
DO - 10.1124/mol.107.038331
M3 - Journal article
C2 - 17636045
SN - 0026-895X
VL - 72
SP - 1033
EP - 1044
JO - Molecular Pharmacology
JF - Molecular Pharmacology
IS - 4
ER -
