Table 1.

Effect of ET-1 (0.3 nM) and selective antagonism of ET_A (BQ123, 1 μM) and ET_B (BQ788, 0.1 μM) receptors on the concentration-relaxation curves to ACh and to the NO donor in penile arteries from LZR and OZR

	ACh
	LZR				OZR
	Phe	pEC50	Emax	n	Phe	pEC50	Emax	n
Control	2.4 ± 0.5	5.56 ± 0.08	75 ± 5	7	1.1 ± 0.2	5.61 ± 0.15	38 ± 6	7
+ET-1	2.5 ± 0.6	5.27 ± 0.10b	49 ± 5b	4	1.3 ± 0.2	5.54 ± 0.07	28 ± 7b	4
+ET-1 + BQ123	2.6 ± 0.5	5.72 ± 0.19c	65 ± 6c	3	1.3 ± 0.1	5.57 ± 0.13	40 ± 4c	5
+ET-1 + BQ788	2.2 ± 0.3	5.52 ± 0.07	55 ± 8a	4	1.5 ± 0.3	5.43 ± 0.11	38 ± 7	4
Control	2.4 ± 0.3	5.74 ± 0.12	83 ± 4	7	1.8 ± 0.2	5.28 ± 0.24	54 ± 6	9
+BQ123	2.2 ± 0.2	5.82 ± 0.13	79 ± 9	3	1.7 ± 0.3	5.52 ± 0.10	58 ± 11	4
+BQ788	2.7 ± 0.3	5.88 ± 0.24	82 ± 4	4	1.5 ± 0.3	4.76 ± 0.12	63 ± 8b	4
+BQ123 + BQ788	2.1 ± 0.3	5.88 ± 0.16	87 ± 6	3	2.0 ± 0.2	5.06 ± 0.13	82 ± 6a	4
	SNAP
	LZR				OZR
	Phe	pEC50	Emax	n	Phe	pEC50	Emax	n
Control	1.6 ± 0.4	6.23 ± 0.12	97 ± 2	8	1.7 ± 0.6	6.19 ± 0.19	89 ± 3	8
+ET-1	1.3 ± 0.4	5.79 ± 0.08b	86 ± 8	4	1.5 ± 0.2	5.57 ± 0.11b	75 ± 5a	4
+ET-1 + BQ123	1.3 ± 0.3	6.28 ± 0.17c	96 ± 2	4	1.3 ± 0.1	5.90 ± 0.19	90 ± 3d	4
+ET-1 + BQ788	1.7 ± 0.3	5.86 ± 0.20	87 ± 6	4	1.1 ± 0.4	6.20 ± 0.12d	77 ± 8	4

Values represent mean ± SEM of the number n of animals (one to two individual arteries were used from each animal). Significant differences from controls were analysed by paired Student's t-test and one-way anova followed by Bonferroni a posterio test. Phe precontraction (Nm⁻¹).

^aP < 0.05;

^bP < 0.01 versus control.

^ccP < 0.05;

^dP < 0.01; versus ET-1-treated.