Inactivation of calcium channels in mammalian heart cells: joint dependence on membrane potential and intracellular calcium.
Key result
Cardiac calcium channel inactivation is jointly dependent on both intracellular calcium concentration and membrane voltage to regulate calcium entry during depolarization.
Population
Cs-loaded calf cardiac Purkinje fibres and Cs-dialysed myocytes from guinea-pig ventricle
Comparison
Manipulation of membrane potential and… vs Baseline/control conditions with standard…
Design
Preclinical
Authors
Discussion
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Implication
Animal data on dual Ca channel inactivation require human validation; leaves open arrhythmia therapy implications.
Structured PICO
P
Population
Cs-loaded calf cardiac Purkinje fibres and Cs-dialysed myocytes from guinea-pig ventricle
I
Intervention
Manipulation of membrane potential and intracellular/extracellular calcium concentrations (including replacement with Sr or Ba)
C
Comparator
Baseline/control conditions with standard extracellular calcium
O
Outcome
Rate and extent of calcium channel current inactivationsurrogate
Cardiac calcium channel inactivation relies on both intracellular calcium and membrane voltage, serving as a negative feedback mechanism to regulate calcium entry.
Cite This Study
Lee et al. (1985) studied this question. Cardiac calcium channel inactivation is jointly dependent on both intracellular calcium concentration and membrane voltage to regulate calcium entry during depolarization.