Figure 1. (A) Relaxant response to 1 micro Meter acetylcholine (ACh) in endothelium-intact segments, in the absence (intact) and presence of NG-nitro-L-arginine (+NNA, 100 micro Meter, n = 12), and in endothelium-denuded segments (n = 10). (B) and (C) Effects of tetrabutylammonium (+TBA, 3 mM, n = 6) and clotrimazole (+CLO, 30 micro Meter, n = 11) on the NG-nitro-L-arginine/diclofenac-resistant relaxant response to acetylcholine (**P < 0.01 vs. control; ns, not significant).