Barium block of the muscarinic potassium current in guinea-pig atrial cells

1995 ◽  
Vol 430 (3) ◽  
pp. 348-357 ◽  
Author(s):  
W. -J. Zang ◽  
X. -J. Yu ◽  
M. R. Boyett
Keyword(s):  
Guinea Pig ◽  
Potassium Current ◽  
Atrial Cells ◽  
Barium Block

scholarly journals Histamine H1 -receptor-mediated modulation of the delayed rectifier K+ current in guinea-pig atrial cells: opposite effects on IKs and IKr

1999 ◽  
Vol 128 (7) ◽  
pp. 1545-1553 ◽  
Author(s):  
Yasunori Matsumoto ◽  
Takehiko Ogura ◽  
Hiroko Uemura ◽  
Toshihiro Saito ◽  
Yoshiaki Masuda ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Delayed Rectifier ◽  
H1 Receptor ◽  
Histamine H1 Receptor ◽  
Atrial Cells ◽  
K Current

Rectification of muscarinic K+ current by magnesium ion in guinea pig atrial cells

1987 ◽  
Vol 253 (1) ◽  
pp. H210-H214
Author(s):  
M. Horie ◽  
H. Irisawa
Keyword(s):  
Guinea Pig ◽  
Action Potentials ◽  
Single Channel ◽  
Outward Current ◽  
Atrial Cells ◽  
Voltage Dependent ◽  
K Current ◽  
Single Channel Currents ◽  
Channel Currents ◽  
Low K

Rectifying properties of the acetylcholine (ACh)-sensitive K+ channels were studied using a patch-clamp method in single atrial cells prepared enzymatically from adult guinea pig hearts. In the presence of micromolar concentration of nonhydrolyzable guanosine 5'-triphosphate (GTP) analogue 5'-guanylylimidodiphosphate (GppNHp) and the absence of Mg2+ at the inner surface of patch membrane [( Mg2+]i), the channel activity recovered in inside-out patch condition. The single channel conductance became ohmic between -80 and +80 mV (symmetrical 150 mM K+ solutions). The rapid relaxation of outward single channel currents was disclosed on a depolarization. [Mg2+]i blocked the outward current through the channel dose- and voltage-dependently and also induced a dose-dependent increase in the channel activation. The apparent paradoxical role of [Mg2+]i is important for the cholinergic control in the heart; voltage-dependent Mg block ensures a low K+ conductance of cell membrane at the plateau of action potentials during the exposure to ACh, thereby slowing the heart rate without unfavorable shortening of the action potentials.

Inhibition of Muscarinic Potassium Current by the Class III Antiarrhythmic Drug RP58866 in Guinea-Pig Atrial Myocytes

2000 ◽  
Vol 23 (11P2) ◽  
pp. 1812-1815 ◽  
Author(s):  
BODO BRANDTS ◽  
MARC VAN BRACHT ◽  
FRANK TÜTTELMANN ◽  
MAURITZ A. ALLESSIE ◽  
HANS-JOACHIM TRAPPE
Keyword(s):  
Guinea Pig ◽  
Antiarrhythmic Drug ◽  
Potassium Current ◽  
Class Iii ◽  
Atrial Myocytes ◽  
Class Iii Antiarrhythmic Drug
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