Table 4.

Effect of ODQ, glibenclamide, apamin and a combination of potassium channel blockers on smooth muscle membrane potential and hyperpolarization induced by NaHS

Treatment	n	Membrane potential (mV)			Net effect on MP (mV)
		Basal1	Pretreatment2	NaHS 0.3 mM3	Pretreatment2	NaHS 0.3 mM3
Control	4	−40.8 ± 0.8	–	−50.3 ± 1.3b	–	−9.5 ± 0.8
ODQ 10 μM	4	−44.4 ± 2.2	−41.6 ± 2.8a	−48.3 ± 2.9c	+2.8 ± 0.7	−6.7 ± 0.5
Gliben 10 μM	4	−48.1 ± 2.0	−44.5 ± 2.9a	−48.7 ± 2.8a	+3.6 ± 1.1	−4.2 ± 0.7
Apamin 1 μM	4	−46.5 ± 3.1	−41.4 ± 2.4a	−45.2 ± 1.8a	+5.1 ± 1.2	−3.8 ± 0.7
K+ blockers4	3	−40.0 ± 0.4	−36.4 ± 0.7	−39.2 ± 0.9	+3.6 ± 1.0	−2.8 ± 0.8

Values are means ± SEM. n, no. of samples. MP, membrane potential; Gliben, glibenclamide.

¹Smooth muscle cells resting membrane potential (when no drug has been added).

²Pretreatment: effect of the drug (treatment column) incubated before NaHS.

³Effect of NaHS on smooth muscle membrane potential.

⁴Combination of K + blockers comprised glibenclamide 10 μM, apamin 1 μM, charybdotoxin 0.1 μM and TRAM-34 1 μM.

Note that positive and negative symbols included in the net effect column indicate the depolarization or the hyperpolarization observed by the drug (for pretreatment calculated from basal values and for NaHS 0.3 mM calculated from the values of membrane potential observed after the addition of the pretreatment drugs).

^aP < 0.05;

^bP < 0.01;

^cP < 0.001, significant differences; paired Student's t-test (pretreatment vs. basal and NaHS 0.3 mM vs. pretreatment; for control NaHS 0.3 mM was compared to basal).