Table 2

EC₅₀ for vasoconstrictors and dilators

Agonist	n	EC₅₀	Maximum Response
		M	%
Constrictor
NE	3	6.68 (3.39–13.18) × 10⁻⁸	73.3 ± 5.9^2-a
NPY	7	2.33 (1.65–3.29) × 10⁻⁹ ^2-150	81.9 ± 8.5^2-a
Dilator
SNP	7	2.03 (0.16–25.95) × 10⁻⁸ ^**	100 ± 0^2-b
SP	6	0.83 (0.23–3.04) × 10⁻⁸ ^**	58.9 ± 9.3^2-b
5-HT	7	4.54 (1.96–10.52) × 10⁻⁹ ^**	98.2 ± 0.9^2-b
CGRP	6	0.96 (0.31–2.97) × 10⁻⁹	59.7 ± 7.4^2-b
VIP	9	0.93 (0.48–1.77) × 10⁻⁹	100 ± 0^2-b

↵2-a Percentage of 3 × 10⁻⁷ M U-46619-induced constriction.
↵2-b Percentage of papaverine-induced maximum relaxation.
↵2-150 P < .01 vs norepinephrine and ** P< .05 vs VIP, indicate significant differences (unpaired Student’st test).