Fig. 4. The effect of H2S and pinacidil on KATP channel currents in rat aortic SMCs. (A) The effect of H2S on KATP channel currents. The original records from one cell (left) and the mean current–voltage relationship of six cells (right) in the absence and then presence of H2S (300 µM) are shown. (B) The effect of pinacidil (5 µM) on KATP channel currents. The original records from one cell (left) and the mean current–voltage relationship of five cells (right) in the absence and then presence of pinacidil are shown. Dashed line indicates zero current level. (C) The antagonistic effect of glibenclamide (Gli, 5 µM) on the effect of H2S or pinacidil (Pin) on KATP channel currents (holding potential, –60 mV; test potential, +40 mV). (D) The membrane hyperpolarization induced by H2S (300 µM) or pinacidil (5 µM), respectively. *P < 0.05 compared with control; n = 3–7 for each group.