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Updated: May 10, 2026
08:11
Voltage-Dependent Potassium Current Recording on H9c2 Cardiomyocytes via the Whole-Cell Patch-Clamp Technique
Published on: November 11, 2022
The cardiac sodium current Na(v)1.5 is functionally expressed in rabbit bronchial smooth muscle cells
E Bradley1, T I Webb, M A Hollywood
1Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland.
American Journal of Physiology. Cell Physiology
|June 21, 2013
Summary
Freshly isolated airway smooth muscle cells (ASMC) from rabbits exhibit a fast voltage-gated sodium (Na+) current, primarily mediated by the NaV1.5 subtype. This finding is crucial for understanding ASMC function and potential therapeutic targets.
Area of Science:
- Physiology
- Molecular Biology
- Pharmacology
Background:
- Airway smooth muscle cells (ASMC) play a critical role in regulating airway caliber.
- Voltage-gated sodium channels (VGSCs) are known to be expressed in various cell types, influencing cellular excitability.
- The specific contribution of VGSCs to ASMC function remains incompletely understood.
Purpose of the Study:
- To investigate the presence and characteristics of voltage-gated sodium currents in rabbit ASMC.
- To identify the specific VGSC subtypes responsible for these currents.
- To assess the functional impact of VGSC activity on ASMC electrophysiology.
Main Methods:
- Isolation of rabbit ASMC using enzymatic digestion (collagenase-proteinase mixture).
- Electrophysiological recordings of membrane currents using the whole-cell patch-clamp technique.
- Reverse transcription polymerase chain reaction (RT-PCR) to detect VGSC mRNA expression in single cells and tissue.
Main Results:
- A fast, voltage-dependent sodium (Na+) current was evoked in isolated ASMC.
- The current exhibited properties similar to NaV1.5 α-subunits and was sensitive to tetrodotoxin (TTX) and lidocaine.
- RT-PCR analysis detected NaV1.2 and NaV1.5 transcripts in single ASMC, with NaV1.5 being the predominant subtype.
Conclusions:
- Freshly dispersed rabbit ASMC express a functional fast voltage-gated Na+ current.
- This current is primarily mediated by the NaV1.5 subtype.
- These findings provide insights into the electrophysiological properties of ASMC and potential roles of NaV1.5 in airway smooth muscle function.
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