Figure 2. Concentration-response curves to cromakalim and pinacidil in the absence or the presence of lidocaine (10-5, 3 x 10-5, 10-4, 3 x 10-4M) obtained in rat thoracic aortas without endothelia. Data are shown as the mean +/− SD and expressed as percent of maximal relaxation induced by papaverine (3 x 10-4M; 100%= 864 +/− 159 mg [n = 5], 820 +/− 219 mg [n = 6], 816 +/− 201 mg [n = 5], 744 +/− 104 mg [n = 5], and 744 +/− 149 mg [n = 5] for control rings of cromakalim and rings treated with lidocaine [10-5M], lidocaine [3 x 10-5M], lidocaine [10-4M], or lidocaine (3 x 10-4M]; 100%= 840 +/− 215 mg [n = 5], 832 +/− 216 mg [n = 5], 872 +/− 232 mg [n = 5], 856 +/− 189 mg [n = 5], and 800 +/− 110 mg [n = 5] for control rings of pinacidil and rings treated with lidocaine [10-5M], lidocaine [3 x 10-5M], lidocaine [10-4M], or lidocaine [3 x 10-4M], respectively). *Difference between control rings and rings treated with lidocaine is statistically significant (P < 0.05).