Key Points
- The aim is to identify and characterize ionic currents activated during hyperpolarization in single right atrial myocytes.
- Whole-cell recording techniques were utilized on single right atrial myocytes.
- Ionic currents were activated by hyperpolarizing voltage pulses negative to -30 mV.
- Cells were categorized based on the ionic currents observed during hyperpolarization.
- The first cell type exhibited a potassium current iK1, reversible near the potassium equilibrium potential, and blocked by barium or cesium.
- A second cell type demonstrated an if current with activation range between -50 and -110 mV, blocked by cesium.
- A third cell type revealed a combination of iK1 and if currents, while a fourth type displayed only small time-independent leak currents.
Structured PICO
PPopulationSingle right atrial myocytes from cat heart
IInterventionHyperpolarizing voltage pulses negative to -30 mV using whole-cell recording techniques
OOutcomeIonic currents activated during hyperpolarization
Individual cells within the right atrium are electrophysiologically heterogeneous with respect to ionic channels, which partially explains the diverse diastolic voltage characteristics of atrial tissue.