Fig. 4. Concentration–response curves for levcromakalim in the presence of mexiletine (10−4m), glibenclamide (5 × 10−6m), or both, obtained in rat thoracic aortas without endothelium in the Krebs-Ringer solutions at different pH values. Data are shown as mean ± SD and expressed as percent of maximal relaxation induced by papaverine (3 × 10−4m; 100%= 1,328 ± 299 mg [n = 5] and 1,360 ± 217 mg [n = 5] for rings treated with 10−4m mexiletine or 10−4m mexiletine plus 10−5m glibenclamide in pH 7.2; 1,015 ± 130 mg [n = 5] and 1,065 ± 30 mg [n = 5] for rings treated with 10−4m mexiletine or 10−4m mexiletine plus 10−5m glibenclamide in pH 7.4; 1,032 ± 183 mg [n = 5] and 1,088 ± 132 mg [n = 5] for rings treated with 10−4m mexiletine or 10−4m mexiletine plus 10−5m glibenclamide in pH 7.6, respectively). *Differences between rings treated with 10−4m mexiletine and 10−4m mexiletine plus 10−5m glibenclamide are statistically significant (P < 0.05).