TY - JOUR
T1 - An ATP, calcium and voltage sensitive potassium channel in porcine coronary artery smooth muscle cells
AU - Silberberg, Shai D.
AU - van Breemen, Cornelis
N1 - Funding Information:
We thank Drs. D.J. Adams and D.S. Weiss for helpful discussion, Dr. A.M.J. van Dongen and A. Mandveno for the use of several analysis programs and M. Lam for technical assistance. This work was supported by HL-35657. SDS is a Research Fellow of the American Heart Association, Florida Affiliate, Inc.
PY - 1990/10/30
Y1 - 1990/10/30
N2 - There is increasing interest in the roles played by potassium channels of smooth muscle in protecting against ischemic and anoxic insults. Hence, potassium-selective channels were studied in freshly dispersed porcine coronary artery smooth muscle cells using the inside-out variant of the patch-clamp technique. The most abundant potassium channel had a conductance of 148 pS in a 5.4 140 mM K+ gradient, at 0 mV, and was regulated by cytoplasmic ATP (0.05 - 3.0 mM), cytoplasmic Ca2+ (0.1-10 μM) and voltage. ATP and AMP-PNP (0.5 mM) reduced the probability of channel opening (P0) by 87 and 92%, respectively. This inhibition was partially reversed by the addition of 0.5 mM ADP. ADP on its own (2 mM) reduced P0 by 46%. It appears, therefore, that this channel shares properties with both the ATP-sensitive and the calcium-regulated potassium channels, raising the possibility that it plays a central role in the regulation of coronary blood flow.
AB - There is increasing interest in the roles played by potassium channels of smooth muscle in protecting against ischemic and anoxic insults. Hence, potassium-selective channels were studied in freshly dispersed porcine coronary artery smooth muscle cells using the inside-out variant of the patch-clamp technique. The most abundant potassium channel had a conductance of 148 pS in a 5.4 140 mM K+ gradient, at 0 mV, and was regulated by cytoplasmic ATP (0.05 - 3.0 mM), cytoplasmic Ca2+ (0.1-10 μM) and voltage. ATP and AMP-PNP (0.5 mM) reduced the probability of channel opening (P0) by 87 and 92%, respectively. This inhibition was partially reversed by the addition of 0.5 mM ADP. ADP on its own (2 mM) reduced P0 by 46%. It appears, therefore, that this channel shares properties with both the ATP-sensitive and the calcium-regulated potassium channels, raising the possibility that it plays a central role in the regulation of coronary blood flow.
UR - http://www.scopus.com/inward/record.url?scp=0024996674&partnerID=8YFLogxK
U2 - 10.1016/0006-291X(90)90703-P
DO - 10.1016/0006-291X(90)90703-P
M3 - Article
AN - SCOPUS:0024996674
SN - 0006-291X
VL - 172
SP - 517
EP - 522
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 2
ER -