Fig. 2. Dose–response curve of the inhibitory effect of isoflurane on hypoxic pulmonary vasoconstriction (HPV) in the absence and presence of potassium channel inhibitors, n = 6 per group. *Right shift compared with the control-ISO group (P < 0.05); #left shift compared with the control-ISO group (P < 0.05). The concentration of isoflurane that induced 50% inhibition of HPV (ED50) was 0.93 ± 0.08 MAC in the control-ISO group, 0.91 ± 0.22 MAC in the Glib-ISO group, 1.15 ± 0.10 MAC in the 4AP-ISO group (P < 0.05 vs. the control-ISO group), and 0.59 ± 0.18 MAC in the IbTX-ISO group (P < 0.05 vs. the control-ISO group). Glib = glibenclamide, the adenosine triphosphate–sensitive potassium (KATP)-channel inhibitor; 4-AP = 4-aminopyridine, the voltage-sensitive potassium (KV) channel inhibitor; IbTX = iberiotoxin, the high-conductance calcium-activated potassium (KCa)-channel inhibitor; ISO = isoflurane.