Effects of glibenclamide (glib) and iberiotoxin (IbTX) on smooth muscle hyperpolarization induced by levcromakalim (LK), NOR-1, iloprost and bradykinin in segments of intact porcine coronary arteries in the presence of 300 μM nitro-L-arginine+10 μM indomethacin. (a) Continuous trace showing typical responses. (b) Graphical representation of data from four separate experiments of the types shown in (a) in which each column represents the membrane potential (m.p.),+or−s.e.mean, before and after exposure bolus doses of levcromakalim (100 nmol), NOR-1 (100 nmol), iloprost (1 nmol) or bradykinin (300 pmol) calculated to give, transiently, the final bath concentrations indicated.