Fig. 2. Effect of protein kinase inhibitors on isoflurane-induced adenosine triphosphate-sensitive potassium channel activation in native vascular smooth muscle cells. (  A ) Effects of pretreatment (10 min) with calphostin C, a selective protein kinase C inhibitor. (  B ) Effects of pretreatment (10 min) with Rp-cAMPS, a selective protein kinase A inhibitor. Membrane potentials were clamped at −60 mV. Zero current levels are indicated by the  horizontal lines marked “0 pA.” Isoflurane was superfused to the bath solution as indicated by the  horizontal solid bars . (  C ) Summary of changes in NPo. Each  vertical bar constitutes measurements from 15–20 patches (mean ± SD). *  P < 0.05  versus baseline. §  P < 0.05  versus isoflurane alone.