Dihydropyridine receptors are primarily functional L-type calcium channels in rabbit ventricular myocytes.
Population
Rabbit ventricular myocytes and ventricular homogenates
Design
Preclinical
Authors
Discussion
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Implication
Indicates matched receptor-channel densities in rabbit myocytes; challenges skeletal muscle models but leaves open human translation.
Key Points
- This research aims to investigate the relationship between dihydropyridine receptor density and functional L-type calcium channels in rabbit ventricular myocytes.
- Measured [3H]PN200-110 binding and patch-clamp currents in rabbit ventricular myocytes.
- Calculated dihydropyridine receptor density and functional L-type calcium channel density based on whole-cell and single-channel measurements.
- Assessed sodium current through calcium channels to avoid calcium-induced inactivation.
- Dihydropyridine receptor density was found to be 12.9 sites/micron2 in ventricular homogenates and 14.8 sites/micron2 in myocytes.
- Functional L-type calcium channels density was approximately 18 channels/micron2 based on the calculated values from ionic measurements.
- Peak sodium current through calcium channels was approximately 105 pA/pF, with a single-channel conductance of 40.8 pS.
Structured PICO
P
Population
Rabbit ventricular myocytes and ventricular homogenates
I
Intervention
Measurement of [3H]PN200-110 binding and patch-clamp currents
O
Outcome
Density of dihydropyridine-specific receptors and functional L-type calcium channelssurrogate
In rabbit ventricular myocytes, the density of dihydropyridine receptors closely matches the density of functional L-type calcium channels, unlike what has been reported in skeletal muscle.
Cite This Study
Lew et al. (1991) studied this question.