Fig. 3. Dose–response curve of the inhibitory effect of sevoflurane on hypoxic pulmonary vasoconstriction (HPV) in the absence and presence of potassium channel inhibitors, n = 8 per group. There are no significant differences among the groups. The concentration of isoflurane that induced 50% inhibition of HPV (ED⁵⁰) was 0.82 ± 0.21 MAC in the control-SEVO group, 0.87 ± 0.25 MAC in the Glib-SEVO group, 0.96 ± 0.24 MAC in the 4AP-SEVO group, and 0.76 ± 0.17 MAC in the IbTX-SEVO group. Glib = glibenclamide, the adenosine triphosphate–sensitive potassium (K^ATP)-channel inhibitor; 4-AP = 4-aminopyridine, the voltage-sensitive potassium (K^V)-channel inhibitor; IbTX = iberiotoxin, the high-conductance calcium-activated potassium (K^Ca) channel inhibitor; SEVO = sevoflurane.