Figure 6.

Lack of effects of mAChR subtype-selective antagonists on the pilocarpine-induced K⁺ current in canine atrial myocytes. Currents were elicited in the presence of 10 μM pilocarpine, with voltage protocols same as described in Figure 4. Upper panels: Analogue data from representative myocytes showing effects of pirenzepine (PZ, 100 nM (A)), methoctramine (MA, 20 nM (B)), and tropicamide (TA, 200 nM (C)). Only currents recorded at a TP of +50 mV are shown for the sake of clarity. Bottom panels: Current density of the pilocarpine-induced K⁺ current before and after antagonists, measured at +50 mV (n=3 for PZ, n=4 for MA, and n=3 for PA).