Relationship between action potential duration of ventricular cells and heart rate of rabbit under natural breathing

1984 ◽  
Vol 4 (1) ◽  
pp. 16-20 ◽  
Author(s):  
Li Shao-ru ◽  
Ding Bao-chun ◽  
Jin Yong-wan
Keyword(s):  
Heart Rate ◽  
Action Potential ◽  
Action Potential Duration ◽  
Ventricular Cells ◽  
Natural Breathing

Relationship between action potential duration of ventricular cells and heart rate in dog under natural breathing

1987 ◽  
Vol 7 (3) ◽  
pp. 148-152
Author(s):  
Tang Ming ◽  
Zhang Guang-lan ◽  
Zeng Xiao-rong ◽  
Zhong Jun-yuan ◽  
Zhang Yi ◽  
...  
Keyword(s):  
Heart Rate ◽  
Action Potential ◽  
Action Potential Duration ◽  
Ventricular Cells ◽  
Natural Breathing

Cytosolic magnesium modulates calcium channel activity in mammalian ventricular cells

1989 ◽  
Vol 256 (2) ◽  
pp. C452-C455 ◽  
Author(s):  
Z. S. Agus ◽  
E. Kelepouris ◽  
I. Dukes ◽  
M. Morad
Keyword(s):  
Action Potential ◽  
Calcium Channel ◽  
Action Potential Duration ◽  
Calcium Current ◽  
Concentration Addition ◽  
High Threshold ◽  
Channel Activity ◽  
Mean Values ◽  
Ventricular Cells ◽  
In Cells

The effect of cytosolic free Mg2+ concentration on the regulation of myocardial function was studied by dialyzing isolated guinea pig ventricular myocytes with different internal Mg2+ concentrations [( Mg2+]i). We found that elevation of [Mg2+]i shortened the action potential and suppressed the Ca2+ current. Mean values recorded for action potential duration in cells dialyzed with solutions containing 0, 1.3, and 9.4 mM Mg2+ were 620 +/- 40, 400 +/- 25, and 60 +/- 10, respectively. The suppressive effect of [Mg2+]i on the action potential duration correlated significantly with the suppressive effects of [Mg2+]i on the Ca2+ current. In cells dialyzed with nominally zero Mg2+, calcium current was prominent (3.5 +/- 0.58 nA). At [Mg2+]i of 1.4 mM, calcium current was significantly smaller than in zero [Mg2+]i and was almost completely inhibited by dialysis of the cell with 9.4 mM Mg2+. The Mg2+-induced block of the Ca2+ current was due to steady-state inactivation of the high threshold calcium channel. The block was observed in the presence or absence of adenosine 3',5'-cylic monophosphate and was not reversed by elevation of external Ca2+ concentration, addition of adrenaline, or large negative potentials. These data suggest that cytosolic Mg2+ regulates Ca2+ channel activity by a novel mechanism, unrelated to its effect as a blocking particle of the open channel.

scholarly journals Cardiovascular parameters in rat model of chronic renal failure induced by subtotal nephrectomy

2010 ◽  
pp. S81-S88 ◽  
Author(s):  
J Švíglerová ◽  
J Kuncová ◽  
L Nalos ◽  
Z Tonar ◽  
D Rajdl ◽  
...  
Keyword(s):  
Heart Rate ◽  
Renal Failure ◽  
Chronic Renal Failure ◽  
Left Ventricle ◽  
Action Potential ◽  
Action Potential Duration ◽  
Cardiovascular Complications ◽  
Resting Heart Rate ◽  
Cardiovascular Parameters ◽  
Subtotal Nephrectomy

Chronic renal failure (CRF) is associated with high incidence of cardiovascular complications. To clarify pathogenesis of CRF numerous animal models have been developed. The aim of our work was to describe methodology of subtotal surgical renal ablation in rat and to characterize some biochemical and cardiovascular parameters of this animal model. Male rats underwent 5/6 surgical nephrectomy or sham operations in two steps. The following parameters were measured on day 10 and in week 10 after the surgery: plasma concentrations of creatinine and urea, blood pressure, resting heart rate, chronotropic response to atropine and metipranol, heart ventricles weight, contraction parameters and action potential duration in the left ventricle. Increased serum concentrations of creatinine and urea, decreased creatinine clearance, polyuria and alteration of the remnant kidney tissue were found in CRF rats. Changes in cardiovascular parameters identified after subtotal nephrectomy resembled alterations of cardiovascular system in uremic patients and included hypertension, elevated resting heart rate, diminished parasympathetic cardiac tone, hypertrophy of the left ventricle associated with weakened force of contraction, prolonged contraction and relaxation and shortening of action potential duration. These data suggest that the present model can be a useful tool in the study of CRF and its cardiovascular complications.

scholarly journals OSU-03012, a novel celecoxib derivative, induces cell swelling and shortens action potential duration in mouse ventricular cells

2010 ◽  
Vol 31 (6) ◽  
pp. 413-417 ◽  
Author(s):  
Shintaro Yamamoto ◽  
Takuya Iyoda ◽  
Satomi Kita ◽  
Toshiki Yamada ◽  
Takahiro Iwamoto
Keyword(s):  
Action Potential ◽  
Action Potential Duration ◽  
Cell Swelling ◽  
Ventricular Cells

The dependence on heart rate of the human ventricular action potential duration

1982 ◽  
Vol 16 (10) ◽  
pp. 547-551 ◽  
Author(s):  
L ARNOLD ◽  
J PAGE ◽  
D ATTWELL ◽  
M CANNELL ◽  
D A EISNER
Keyword(s):  
Heart Rate ◽  
Action Potential ◽  
Action Potential Duration ◽  
Ventricular Action Potential

Effect of intravenous ketanserin on the human action potential duration at fixed heart rate

1988 ◽  
Vol 2 (2) ◽  
pp. 239-243 ◽  
Author(s):  
Angela J. Drake-Holland ◽  
Mark I. M. Noble ◽  
Sara Pugh ◽  
Christopher Mills
Keyword(s):  
Heart Rate ◽  
Action Potential ◽  
Action Potential Duration ◽  
Human Action

Heart Rate and Myocardial Action Potential Duration

1981 ◽  
Vol 60 (3) ◽  
pp. 28P-29P
Author(s):  
M. J. Lab ◽  
M. I. M. Noble ◽  
D. Papadoyannis ◽  
J. W. Pidgeon ◽  
W. A. Seed
Keyword(s):  
Heart Rate ◽  
Action Potential ◽  
Action Potential Duration

Electrotonic modulation of electrical activity in rabbit atrioventricular node myocytes

1997 ◽  
Vol 273 (2) ◽  
pp. H767-H776 ◽  
Author(s):  
K. W. Spitzer ◽  
N. Sato ◽  
H. Tanaka ◽  
L. Firek ◽  
M. Zaniboni ◽  
...  
Keyword(s):  
Action Potential ◽  
Action Potential Duration ◽  
Single Channel ◽  
Electrical Coupling ◽  
Atrioventricular Node ◽  
Ventricular Cell ◽  
Nodal Cell ◽  
Ventricular Cells ◽  
Diastolic Depolarization ◽  
Diastolic Potential

Electrotonic effects of electrically coupling atrioventricular (AV) nodal cells to each other and to real and passive models of atrial and ventricular cells were studied using a technique that does not require functional gap junctions. Membrane potential was measured in each cell using suction pipettes. Mutual entrainment of two spontaneously firing AV nodal cells was achieved with a junctional resistance (Rj) of 500 M omega, which corresponds to only 39 junctional channels, assuming a single-channel conductance of 50 pS. Coupling of AV nodal and atrial cells at Rj of 50 M omega caused hyperpolarization of the nodal cell, decreasing its action potential duration and either slowing or blocking diastolic depolarization in the AV node myocyte. Opposite changes occurred in the atrial action potential. When AV nodal and ventricular cells were coupled at Rj of 50 M omega, nodal diastolic potential was markedly hyperpolarized and diastolic depolarization was completely blocked with little change in ventricular diastolic potential. However, coupling did elicit marked changes in the action potential duration of both cells, with prolongation in the nodal cell and shortening in the ventricular cell. Nodal maximum upstroke velocity was increased by both atrial and ventricular coupling, as expected from the hyperpolarization that occurred. With an Rj of 50 M omega, spontaneous firing was blocked in all single AV nodal pacemaker cells during coupling to a real or passive model of an atrial or ventricular cell. These results demonstrate that action potential formation and waveform in a single AV nodal cell is significantly affected by electrical coupling to other myocytes.

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