What question did this study set out to answer?

To investigate how the actin and microtubule cytoskeleton modulates voltage-dependent steady-state activation and availability from inactivation in cardiac sodium channels.

October 1, 1997AJP Heart and Circulatory Physiology

Cytoskeleton modulates coupling between availability and activation of cardiac sodium channel

View Full Paper

Ask AI

Bookmark

Population

116 rat ventricular cardiomyocytes

Comparison

Cytoskeleton-directed agents vs Untreated cells

Design

Preclinical

Follow-up

63 +/- 5 min

Authors

VMVictor A. MaltsevElectrophysiology AUA. I. UndrovinasHenry Ford Hospital

Discussion

Member takes

Implication

Cytoskeletal modulation of Na channel coupling shown in rat myocytes; leaves open relevance to human arrhythmias or therapies.

Key Points

To investigate how the actin and microtubule cytoskeleton modulates voltage-dependent steady-state activation and availability from inactivation in cardiac sodium channels.
Performed long-lasting whole-cell patch-clamp recordings (63 ± 5 min) at 22–24°C in 116 isolated rat ventricular cardiomyocytes.
Monitored half-point potentials of steady-state availability (V1/2A) and normalized conductance (V1/2G) over time.
Tested cytoskeletal modulators including cytochalasin D (20 µM), phalloidin (100 µM), and taxol (100 µM).
Both V1/2A and V1/2G shifted negatively over time in untreated cells, fitting a second-degree (2.06) power function across 1,021 measurements in 51 cells.
The F-actin disrupter cytochalasin D accelerated the V1/2A shift, decreased the V1/2G shift range, and shifted the V1/2G–V1/2A relationship by +2.5 mV, whereas phalloidin temporarily blocked the V1/2A shift for 28.2 ± 2.2 min (n = 15).
The microtubule stabilizer taxol altered gating coupling by shifting the V1/2G–V1/2A relationship by -12.2 mV toward more negative V1/2G values.

Structured PICO

Population

116 rat ventricular cardiomyocytes

Intervention

Cytoskeleton-directed agents (cytochalasin D 20 microM, phalloidin 100 microM, taxol 100 microM)

Comparator

Untreated cells

Outcome

Half-point potentials of the steady-state availability curve (V(1/2A)) and normalized conductance curve (V(1/2G))surrogate

The F-actin-based and microtubular cytoskeleton modulates the coupling between availability and activation of cardiac sodium channels in rat ventricular cardiomyocytes.

Cite This Study

Maltsev et al. (1997) studied this question.

synapsesocial.com/papers/6a1f4412e800721f04833f0b https://doi.org/10.1152/ajpheart.1997.273.4.h1832

View Full Paper

Ask AI

Bookmark

Cytoskeleton modulates coupling between availability and activation of cardiac sodium channel

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Cytoskeleton modulates coupling between availability and activation of cardiac sodium channel

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider