Figure 2: Effect of potassium channel inhibitors on rat aorta relaxation induced by testosterone. Effect of increasing concentrations of testosterone (1–100  M) in endothelium-denuded rat aortic rings contracted with KCl (60 mM) in presence or absence of the potassium channel inhibitors glibenclamide (GLI; 10  M), 4-aminopyridine (4-AP; 1 mM), or tetraethylammonium (TEA; 1 mM). Each point represents the mean value ± SEM (indicated in vertical bars) from the number of experiments shown in brackets.