Single L-VDCC gating of young and old tg Ca_V1.2 resembles data obtained from human non-failing and failing ventricle

In a previous study [6] we found single-channel activity to be significantly increased in ventricular myocytes from human hearts failing due to idiopathic dilated cardiomyopathy compared to non-failing ventricles. In excellent agreement the present study reveals activity of single L-VDCC from ≥9 months old, i.e. failing murine hearts overexpressing the human Ca_V1.2 to be significantly increased compared to single-channel activity in 4 months old, i.e. non-failing young transgenics obtained in a previous study [16]. Charge carrier: 70 mM Ba²⁺; holding potential: −100 mV; test potential: +20 mV. Note that Schroder et al. [6] did not use a depolarizing bath solution, thus potentials are approximate values.

p<0.05 and ⁽*⁾p = 0.07 in a Student's t-test; ^†p<0.05 in a Mann-Whitney test (performed when data failed normality test). Numbers of experiments given in parentheses indicate number of experiments with only one channel in the patch.