Figure 5.

Effect of ET receptor antagonists on the ET-1-induced superoxide production in corpus cavernosum from LZR and OZR detected by lucigenin-enhanced chemiluminescence. Average effects of (A) the ET_A receptor antagonist BQ123 (1 μM) and (B) the ET_B receptor antagonist BQ788 (0.1 μM) on basal and on the ET-1 (10 nM)-stimulated superoxide generation in LZR and OZR. Superoxide production is expressed as counts per minute (cpm) mg⁻¹ of tissue. Experiments were performed in the presence of the NOS inhibitor L-NOARG (100 μM). Data are shown as the means ± SEM of n = 3–5 animals (two corpus cavernosum samples from each animal). Five to 10 corpus cavernosum samples. *P < 0.05 versus basal, ^†P < 0.05 versus ET-1-treated; Student's t-test for unpaired observations.