Comparison of effects of magnesium valproate and sodium valproate on the action potential of isolated papillary muscle from guinea pigs and dogs

1990 ◽  
Vol 10 (4) ◽  
pp. 248-251
Author(s):  
Ding Bao-chun ◽  
Gao Zhi-yuan ◽  
Wu Mei ◽  
Pi Xiu-jun ◽  
Wang Hong-qiang
Keyword(s):  
Action Potential ◽  
Sodium Valproate ◽  
Papillary Muscle ◽  
Guinea Pigs

Adriamycin-induced alterations of the action potential in rat papillary muscle

1980 ◽  
Vol 14 (8) ◽  
pp. 446-450 ◽  
Author(s):  
M L LAZARUS ◽  
K L ROSSNER ◽  
K M ANDERSON
Keyword(s):  
Action Potential ◽  
Papillary Muscle ◽  
Rat Papillary Muscle

Differences in outward currents between neonatal and adult rabbit ventricular cells

1994 ◽  
Vol 266 (3) ◽  
pp. H1184-H1194 ◽  
Author(s):  
J. Sanchez-Chapula ◽  
A. Elizalde ◽  
R. Navarro-Polanco ◽  
H. Barajas
Keyword(s):  
Action Potential ◽  
Papillary Muscle ◽  
Action Potential Duration ◽  
Outward Current ◽  
Stimulation Frequency ◽  
Transient Outward Current ◽  
Adult Rabbit ◽  
Outward Currents ◽  
Recovery From Inactivation ◽  
In Cells

In adult rabbit ventricular preparations, action potential duration is significantly increased when stimulation frequency is increased from 0.1 to 1.0 Hz. In neonatal preparations, a similar change in stimulation frequency produced no significant increase in action potential duration. To identify the ionic basis for this difference, we studied different outward currents in single myocytes from papillary muscle and from epicardial tissue of adult and neonatal rabbits. The densities of the outward currents in neonatal cells were about one-half of the current density in adult cells. The density of the voltage-activated transient outward current (I(to1)) was smaller in cells from papillary muscle than in cells from epicardium in adult and newborn rabbits. We found major differences in the kinetic behavior of I(to1) between adult and neonatal cells: 1) the rate of apparent inactivation was faster in neonatal cells, and 2) the recovery from inactivation was significantly faster in neonatal cells, with a time constant of 113 vs. 1,356 ms. We propose that this marked difference in the recovery from inactivation of I(to1) is the basis for the difference in frequency dependence of action potential duration.

Differential Effects of Halothane, Enflurane, and Isoflurane on Ca2+Transients and Papillary Muscle Tension in Guinea Pigs

1992 ◽  
Vol 76 (1) ◽  
pp. 123-131 ◽  
Author(s):  
Zeljko J. Bosnjak ◽  
Anil Aggarwal ◽  
Lawrence A. Turner ◽  
John M. Kampine ◽  
John P. Kampine
Keyword(s):  
Papillary Muscle ◽  
Guinea Pigs ◽  
Muscle Tension ◽  
Differential Effects
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