Characteristics of Current Fluctuations Originating from Activities of Inward-Rectifier K + Channels in Guinea-Pig Heart Cells

1999 ◽  
Vol 167 (2) ◽  
pp. 141-149
Author(s):  
Y. Yamada ◽  
N. Tohse ◽  
M. Nagashima ◽  
H. Yabu
Keyword(s):  
Guinea Pig ◽  
Inward Rectifier ◽  
Current Fluctuations ◽  
Heart Cells ◽  
Guinea Pig Heart ◽  
K Channels

scholarly journals Two types of delayed rectifying K+ channels in atrial cells of guinea pig heart.

1990 ◽  
Vol 40 (4) ◽  
pp. 479-490 ◽  
Author(s):  
Minoru HORIE ◽  
Seiji HAYASHI ◽  
Chuichi KAWAI
Keyword(s):  
Guinea Pig ◽  
Guinea Pig Heart ◽  
K Channels ◽  
Atrial Cells

Intracellular Ca2+ and protein kinase C modulate K+ current in guinea pig heart cells

1987 ◽  
Vol 253 (5) ◽  
pp. H1321-H1324 ◽  
Author(s):  
N. Tohse ◽  
M. Kameyama ◽  
H. Irisawa
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Guinea Pig ◽  
Cell Voltage ◽  
Delayed Rectifier ◽  
Heart Cells ◽  
Guinea Pig Heart ◽  
Kinase C ◽  
Ventricular Cells ◽  
K Current

Effects of protein kinase C (PKC) and intracellular calcium ion (Cai2+) on the delayed rectifier K+ current (IK) were investigated in the single ventricular cells of guinea pig by use of an internal-dialysis method and a whole cell voltage-clamp technique. 12-O-tetradecanoylphorbol-13-acetate (TPA, 10(-9) M), an activator of PKC, increased the amplitude of IK in the presence of Cai2+ higher than 10(-10) M. This effect of TPA was mimicked by a synthetic diacylglycerol, 1-oleoyl-2-acetylglycerol (OAG), 50 micrograms/ml, 125 microM, and was blocked by 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (10 microM). The above findings suggest that IK channels were phosphorylated by PKC and thereby the amplitude of IK was increased. IK was also increased by elevating the concentration of Cai2+ in the absence of TPA. It is thus indicated that IK channels are modulated by Cai2+ not only through activation of PKC but also directly. Our observation may provide a possible mechanism by which Cai2+ mediates the link between the Ca2+ transients during contraction and the action potential duration.

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