Figure 3.

Membrane depolarization induced rapid additional inhibition of the cationic current by SK&F 96365. Carbachol was applied at the moment indicated and was maintained at 50 μM throughout the experiment. SK&F 96365 applied at −40 mV partially inhibited cationic current with a time constant of 9.4 s. Upon voltage step to 80 mV additional strong inhibition with a time constant of 0.6 s occurred which was relieved after repolarization to −40 mV with a time constant of 5.6 s (superimposed dotted lines show single exponential fittings). Note the 7 min gap in the record to wash out SK&F 96365.