Figure 3. Concentration-response curves to diltiazem (10-7to 3 x 10 (-4) M) in the absence and the presence of lidocaine (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%= 736 +/− 104 mg [n = 5], 712 +/− 156 mg [n = 5] for control rings and rings treated with lidocaine).