Table 1. Inhibition of agonist-stimulated [³⁵S]GTPγS binding in cloned human μ, δ, and κ opioid receptors.

Compound	Ke (nM)a			μ/κ	δ/κ
	μ, DAMGO	δ, DPDPE	κ, U69,593
JDTic	25 ± 4	74 ± 2	0.02 ± 0.01	1,250	3,800
1	3.96 ± 1.1	281 ± 44	0.051 ± 0.01	77	5,510
2	14.5 ± 2.6	590 ± 130	0.43 ± 0.12	33	1,372
3a	45.4 ± 15	1140 ± 70	0.51 ± 0.08	89	2,235
3b	49.2 ± 14	>3000	0.18 ± 0.01	273	>16,700
4a	57.1 ± 15	690 ± 250	0.51 ± 0.14	112	1,353
4b	154 ± 56	2,510 ± 490	1.75 ± 0.65	88	1,434
5	3.93 ± 0.73	118 ± 27	0.12 ± 0.02	33	983

^aK_e values are the mean ± SEM of at least three independent experiments performed in duplicates.