Table 2.

Effects of endothelium removal (-Endo) and of the inhibitors of NOS, L-NNA (100 µM), and PI3K, LY-294002 (1 µM) on the relaxant responses to insulin and to acetylcholine in penile arteries from LZR and OZR

	Insulin (100 nM)				Acetylcholine (10 µM)
	LZR	N	OZR	n	LZR	n	OZR	n
Control	29.7 ± 8.9	7	9.1 ± 9.0	7	65.1 ± 9.9	7	57.4 ± 6.1	7
-Endo	−2.7 ± 3.3b	7	2.0 ± 4.2	6	4.5 ± 4.1c	7	7.8 ± 5.2c	6
Control	34.9 ± 6.8	8	16.0 ± 8.8	6	53.8 ± 9.9	8	43.1 ± 15.3	6
L-NNA	7.4 ± 8.4a	7	8.0 ± 5.3	7	29.3 ±8.5a	7	16.8 ± 6.1a	7
Control	20.2 ± 4.8	6	12.6 ± 3.4	7	58.9 ± 6.9	10	57.3 ± 10.9	10
LY-294002	2.0 ± 1.5c	7	3.7 ± 0.9b	8	44.7 ± 12.1	10	45.6 ± 12.1	11

Values represent mean ± SEM of the number n of individual arteries, 1–2 per animal. The relaxant responses to insulin and acetylcholine are expressed as percentage of the contraction induced by phenylephrine (1 µM), prior to the addition of the agonist in each artery. Significant differences from controls were assessed by an unpaired Student's t-test.

^aP < 0.05

^bP < 0.01

^cP < 0.001.

L-NNA, N^ω-nitro-L-arginine; LZR, lean Zucker rat; NOS, nitric oxide synthase; OZR, obese Zucker rat; PI3K, phosphatidylinositol 3-kinase.