ClC‐3 channels were critically involved in the AngII‐induced Cl− current. A. Downregulation of ClC‐3 protein expression with anti‐ClC‐3 siRNA (40 nmol·L−1) decreased AngII‐induced Cl− current in A10 cells. a. Representative traces of AngII‐induced Cl− current in control (con), negative siRNA (neg) or ClC‐3 siRNA‐transfected A10 cells. b. Bar chart from the experiments measured at −80 mV (downward bars) and +80 mV (upward bars) in control (con), negative siRNA (neg) or ClC‐3 siRNA‐transfected A10 cells (n = 6, *P < 0.05 vs. iso, #P < 0.05 vs. Ang). B. The Cl− current was not induced by Ang II in basilar artery smooth muscle cells (BASMC) from ClC‐3 null mice. a. Representative traces of AngII‐induced Cl− current in BASMC of wild type mice (WT) and ClC‐3 null mice (KO). b. Bar chart from the experiments measured at –80 mV (downward bars) and +80 mV (upward bars) in BASMC of wild type mice (WT) and ClC‐3 null mice (KO). n = 6, *P < 0.05 vs. iso.