What is the clinical evidence from this study?

Study design: Other. Population: Embryonic chick heart ventricular cells. Intervention: Whole cell voltage-clamp. Primary outcome: Ionic properties of the fast inward current.

What does this research mean for the field?

Except for a lower current density, the voltage- and time-dependent kinetics of the fast inward sodium current in embryonic chick ventricular myocytes are similar to those in adult cardiac myocytes of other species. Novelty: ClaimNovelty.CONFIRMATORY. Consensus alignment: ConsensusAlignment.SUPPORTS_CONSENSUS.

What question did this study set out to answer?

Determine the ionic and kinetic properties of the fast inward sodium current in isolated ventricular myocytes from embryonic chick hearts.

September 1, 1988AJP Heart and Circulatory Physiology

Fast inward current properties of voltage-clamped ventricular cells of embryonic chick heart

View Full Paper

Ask AI

Bookmark

Key result

Fast inward current kinetics in embryonic chick ventricular cells mirror adult fast Na+ channels across species.

Population

Single ventricular myocytes trypsin dispersed from 16- to 18-day-old embryonic chick hearts

Design

Preclinical

Authors

HSH. SadaKyoto University MKMichio KojimaJikei University School of Medicine NSN. SperelakisTexas Tech University

Discussion

Member takes

Implication

No direct clinical application; leaves open whether embryonic chick Na+ kinetics model adult human channels.

Key Points

Determine the ionic and kinetic properties of the fast inward sodium current in isolated ventricular myocytes from embryonic chick hearts.
Conducted whole-cell patch-clamp electrophysiology on dispersed, spherical ventricular myocytes (10-15 µm diameter, 10.7 pF capacitance) from 16- to 18-day-old chick embryos.
Recorded action potentials and transmembrane currents in 140 mM Na+ bathing solution at 22°C under varying voltages, extracellular sodium concentrations, and tetrodotoxin exposures (10⁻⁶ to 10⁻⁵ M).
Cardiomyocyte action potentials averaged 103 mV in amplitude, -73 mV in resting potential, and 400 ms in duration.
The fast inward current peaked at -1.34 nA (-0.126 mA/µF) at -29 mV with a +35 mV reversal potential, shifting 18 mV upon halving extracellular sodium and showing block by tetrodotoxin.
Steady-state half-inactivation occurred at -90 mV and half-activation at -54 mV, crossing near -73 mV to yield a maximum window conductance of 0.00044 at -50 mV with inactivation time constants decreasing to 1 ms at positive potentials.

Structured PICO

Population

Single ventricular myocytes from 16- to 18-day-old embryonic chick hearts used for whole cell voltage-clamp experiments to determine ionic properties.

Intervention

Whole cell voltage-clamp experiments

Outcome

Ionic properties of the fast inward current (voltage- and time-dependent kinetics)surrogate

The fast inward current in embryonic chick ventricular cells exhibits voltage- and time-dependent kinetics similar to fast Na+ channels in adult hearts, despite lower current density.

Cite This Study

Sada et al. (1988) studied Embryonic chick heart ventricular cells. Whole cell voltage-clamp was evaluated on Ionic properties of the fast inward current. The voltage- and time-dependent kinetics of the fast inward current channel in embryonic chick ventricular cells were similar to fast Na+ channels in adult hearts of other species.

synapsesocial.com/papers/6aa568e4c22cbbe6308e328b https://doi.org/10.1152/ajpheart.1988.255.3.h540

View Full Paper

Ask AI

Bookmark

Fast inward current properties of voltage-clamped ventricular cells of embryonic chick heart

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Fast inward current properties of voltage-clamped ventricular cells of embryonic chick heart

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider