Table 1

Activation Profile of Opioid ligands in HEK-δ Cells

LIGAND
IC50 ± SEM (nM)
Max Inhibition %

Butorphanol
61 ± 12
64 ± 4$
Cyclazocine
6 ± 3
53 ± 2**
Dezocine
477 ± 152
39 + 8
Etorphine
0.2 ± 0.1
67 ± 3$$
Fentanyl
2039 ± 554
71 ± 7$$ #
Hydromorphone
54 ± 31
65 ± 5$
Lofentanil
0.8 ± 0.4
62 ± 7$
Metazocine
159 ± 70
77 ± 4$$
Met-enkephalin
22 ± 17
49 ± 6##
Morphine
1101 ± 614
39 ± 4**
Nalbuphine
545 ± 378
55 ± 7*
Nalorphine
Antagonist

Naltrexone
Antagonist

SKF 10047
184 ± 121
68 ± 9$$
WIN 44,441
40 ± 25
54 ± 6*
Xorphanol
8 ± 2
76 ± 4$$ ##

Inhibitory effect of opioid ligands on Forskolin-stimulated Adenylyl Cyclase activity was measured as described under Materials and Methods. Data for IC50's represent the mean ± SEM obtained from two or more experiments carried out in duplicate. Maximum inhibition is the mean ± SEM of maximum inhibition obtained from a best fit curve as described under "Materials and Methods" (** = P < 0.001, * = P < 0.05 compared to Metazocine), ($$ = P < 0.001, $ = P < 0.05 compared to morphine), (## = P < 0.001, # = P < 0.05 compared to met-enkephalin).

Gharagozlou et al. BMC Neuroscience 2002 3:19   doi:10.1186/1471-2202-3-19