Effects of three metabolites of propiverine on voltage-dependent L-type calcium currents in human atrial myocytes

The non-selective muscarinic receptor antagonist propiverine impairs L-type Ca2+ currents (ICa,L) in human detrusor smooth muscle cells and atrial cardiomyocytes. Here, we have investigated the effects of three metabolites of propiverine on human cardiac ICa,L. Propiverine reduced ICa,L with a − logIC50 [M] value of 4.1, M-5 only showed minor effect on ICa,L at high concentrations, M-6 did not influence ICa,L at all. Like the parent compound M-14 also reduced ICa,L (− logIC50 [M] = 4.6). We conclude, that propiverine and M-14 reduce cardiac ICa,L at higher concentrations than in detrusor cells and therefore preferentially reduce ICa,L in the urinary bladder than in the heart.