Table 1

Single-channel mechanism of drug modulation in hMTC cells

	I_peak	f_active	Mean open time	Mean closed time	P_{o, active}	n
	fA	%	ms		%
Type I
control	−25 ± 3	37 ± 3	0.51 ± 0.04	1.1 ± 0.5	5.2 ± 0.4	8
solvent	−24 ± 5	36 ± 4	0.52 ± 0.05	0.9 ± 0.2	5.1 ± 0.4	8
control	−33 ± 4	43 ± 3	0.63 ± 0.03	1.1 ± 0.2	5.2 ± 0.4	13
Mibefradil (10 μM)	−16 ± 3^1-150	17 ± 3^1-150	0.53 ± 0.05^1-150	1.0 ± 0.2	4.0 ± 0.4^1-150	13
control	−24 ± 2	39 ± 2	0.52 ± 0.03	0.9 ± 0.4	5.5 ± 0.3	10
(S)-Bay K 8644 (1 μM)	−26 ± 3	39 ± 3	0.55 ± 0.05	0.8 ± 0.2	5.2 ± 0.3	10
Type II
control	−18 ± 3	59 ± 6	0.38 ± 0.04	8.1 ± 2.0	2.6 ± 0.4	10
solvent	−15 ± 3	57 ± 8	0.43 ± 0.04	9.5 ± 1.2	2.3 ± 0.2	10
control	−28 ± 5	74 ± 2	0.35 ± 0.01	7.7 ± 1.6	3.9 ± 0.9	7
Mibefradil (10 μM)	−14 ± 2^1-150	44 ± 4^1-150	0.35 ± 0.05	7.2 ± 2.6	2.4 ± 0.4	7
control	−15 ± 3	46 ± 8	0.44 ± 0.06	13.3 ± 1.5	2.3 ± 0.5	9
(S)-Bay K 8644 (1 μM)	−105 ± 25^1-150	46 ± 6	3.03 ± 0.54^1-150	7.1 ± 2.5	14.6 ± 2.9^1-150	9

Effects of solvent, mibefradil (type I, 10.0 ± 0.1 μM; type II, 9.7 ± 0.3 μM), and (S)-Bay K 8644 (type I, 1.02 ± 0.01 μM; type II, 1.01 ± 0.01 μM) on single-channel parameters of type I and II channels in hMTC cells. Data were collected from 0 to 6 min of recording for the first period and from 7 min to the end of experiments for the second period in the case of (S)-Bay K 8644 and solvent. For mibefradil experiments, the first 4 min after application were excluded to allow analysis of the steady-state drug effect (see Figs. 8 and 9). I_peak was measured from ensemble average currents, f_active represents the fraction of active sweeps, open and closed times were averaged from all detected events, and P_{o, active} was calculated as the open probability within active sweeps.

↵1-150 , a significant difference (p < 0.05) between the first and second period.