scholarly journals Effects of Mechanical Stretch on Membrane Currents of Single Ventricular Myocytes of Guinea-Pig Heart.

1992 ◽  
Vol 42 (6) ◽  
pp. 957-970 ◽  
Author(s):  
Norihito SASAKI ◽  
Tamotsu MITSUIYE ◽  
Akinori NOMA
Keyword(s):  
Guinea Pig ◽  
Ventricular Myocytes ◽  
Mechanical Stretch ◽  
Membrane Currents ◽  
Guinea Pig Heart ◽  
Single Ventricular Myocytes

Effects of estrogen on action potential and membrane currents in guinea pig ventricular myocytes

1999 ◽  
Vol 277 (2) ◽  
pp. H826-H833 ◽  
Author(s):  
Seiko Tanabe ◽  
Toshio Hata ◽  
Masayasu Hiraoka
Keyword(s):  
Guinea Pig ◽  
Action Potential ◽  
Action Potentials ◽  
Voltage Dependence ◽  
Ventricular Myocytes ◽  
Membrane Currents ◽  
Patch Clamp Technique ◽  
17Β Estradiol ◽  
Electrophysiological Effects ◽  
Ionic Basis

To explore a possible ionic basis for the prolonged Q-T interval in women compared with that in men, we investigated the electrophysiological effects of estrogen in isolated guinea pig ventricular myocytes. Action potentials and membrane currents were recorded using the whole cell configuration of the patch-clamp technique. Application of 17β-estradiol (10–30 μM) significantly prolonged the action potential duration (APD) at 20% (APD20) and 90% repolarization (APD90) at stimulation rates of 0.1–2.0 Hz. In the presence of 30 μM 17β-estradiol, APD20 and APD90 at 0.1 Hz were prolonged by 46.2 ± 17.1 and 63.4 ± 11.7% of the control ( n = 5), respectively. In the presence of 30 μM 17β-estradiol the peak inward Ca2+ current ( I CaL) was decreased to 80.1 ± 2.5% of the control ( n = 4) without a shift in its voltage dependence. Application of 30 μM 17β-estradiol decreased the rapidly activating component of the delayed outward K+ current ( I Kr) to 63.4 ± 8% and the slowly activating component ( I Ks) to 65.8 ± 8.7% with respect to the control; the inward rectifier K+ current was barely affected. The results suggest that 17β-estradiol prolonged APD mainly by inhibiting the I Kcomponents I Krand I Ks.

Effects of Tilisolol, a Nonselective β-Adrenergic Blocker, on the Membrane Currents of Isolated Guinea Pig Ventricular Myocytes

1997 ◽  
Vol 29 (5) ◽  
pp. 593-598 ◽  
Author(s):  
Shuichi Takagi ◽  
Yasuki Kihara ◽  
Tamotsu Mitsuiye ◽  
Zhuren Wang ◽  
Shigetake Sasayama
Keyword(s):  
Guinea Pig ◽  
Ventricular Myocytes ◽  
Membrane Currents ◽  
Adrenergic Blocker
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