Existence of a sodium current in the tubular membrane of frog twitch muscle fibre; Its possible role in the activation of contraction

1978 ◽  
Vol 374 (2) ◽  
pp. 167-177 ◽  
Author(s):  
Jacques Caill� ◽  
Mich�le Ildefonse ◽  
Oger Rougier
Keyword(s):  
Muscle Fibre ◽  
Sodium Current ◽  
Tubular Membrane

scholarly journals Modelling depolarization delay, sodium currents, and electrical potentials in cardiac transverse tubules

2019 ◽  
Author(s):  
Sarah H. Vermij ◽  
Hugues Abriel ◽  
Jan P. Kucera
Keyword(s):  
Striated Muscle ◽  
Sodium Current ◽  
Cardiac Cells ◽  
Excitation Contraction Coupling ◽  
Contraction Coupling ◽  
Tubular Membrane ◽  
Electrical Potentials ◽  
Tubular Lumen ◽  
T Tubules ◽  
Extracellular Potentials

ABSTRACTT-tubules are invaginations of the lateral membrane of striated muscle cells that provide a large surface for ion channels and signaling proteins, thereby supporting excitation-contraction coupling. T-tubules are often remodeled in heart failure. To better understand the electrical behavior of T-tubules of cardiac cells in health and disease, this study addresses two largely unanswered questions regarding their electrical properties: (1) the delay of T-tubular membrane depolarization and (2) the effects of T-tubular sodium current on T-tubular potentials.Here, we present an elementary computational model to determine the delay in depolarization of deep T-tubular membrane segments as the narrow T-tubular lumen provides resistance against the extracellular current. We compare healthy tubules to tubules with constrictions and diseased tubules from mouse and human, and conclude that constrictions greatly delay T-tubular depolarization, and diseased T-tubules depolarize faster than healthy ones due to tubule widening. We moreover model the effect of T-tubular sodium current on intraluminal T-tubular potentials. We observe that extracellular potentials become negative during the sodium current transient (up to −50 mV in constricted T-tubules), which feedbacks on sodium channel function (self-attenuation) in a manner resembling ephaptic effects that have been described for intercalated discs where opposing membranes are very close together.These results show that (1) the excitation-contraction coupling defects seen in diseased cells cannot be explained by T-tubular remodeling alone; and (2) the sodium current may modulate intraluminal potentials. Such extracellular potentials might also affect excitation-contraction coupling.

Sodium current in human small intestinal interstitial cells of cajal

2001 ◽  
Vol 120 (5) ◽  
pp. A201-A201 ◽  
Author(s):  
P STREGE ◽  
A RICH ◽  
Y OU ◽  
S GIBBONS ◽  
M SARR ◽  
...  
Keyword(s):  
Interstitial Cells Of Cajal ◽  
Sodium Current ◽  
Interstitial Cells ◽  
Small Intestinal ◽  
Cells Of Cajal

Binding, unbinding and aggregation of crescent-shaped nanoparticles on nanoscale tubular membranes

Soft Matter ◽  
2021 ◽  
Author(s):  
Eric J. Spangler ◽  
Alexander D. Olinger ◽  
P. B. Sunil Kumar ◽  
Mohamed Laradji
Keyword(s):  
Phase Diagram ◽  
Adhesion Strength ◽  
Radius Of Curvature ◽  
Tubular Membrane ◽  
Shaped Nanoparticles ◽  
Tubular Membranes

Binding/unbinding phase diagram of a crescent-shaped nanoparticle on a tubular membrane as a function of the tubular membrane radius of curvature and adhesion strength.

scholarly journals Ranolazine Attenuates the Enhanced Reverse Na+-Ca2+ Exchange Current via Inhibiting Hypoxia-Increased Late Sodium Current in Ventricular Myocytes

2014 ◽  
Vol 124 (3) ◽  
pp. 365-373 ◽  
Author(s):  
Xiao-Jing Wang ◽  
Lei-Lei Wang ◽  
Chen Fu ◽  
Pei-Hua Zhang ◽  
Ying Wu ◽  
...  
Keyword(s):  
Ventricular Myocytes ◽  
Sodium Current ◽  
Exchange Current ◽  
Late Sodium Current
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