Table 1 Binding properties and agonist effects of (-)-pentazocine and morphine on human opioid receptor subtypes
MOP/CHO | DOP/CHO | KOP/CHO | ||
|---|---|---|---|---|
Competitive binding assay | ||||
K i value (nM) | ||||
(-)-Pentazocine | 85.6 ± 13.3 | 641 ± 88 | 35.2 ± 2.6 | |
Morphine | 21.0 ± 3.7 | 524 ± 83 | 247 ± 13 | |
cAMP assay | ||||
IC 50 (nM) | ||||
(-)-Pentazocine | 42.8 ± 12.9 | 255 ± 46 | 39.6 ± 14.8 | |
Morphine | 25.0 ± 9.0 | 610 ± 220 | 340 ± 160 | |
I max (%) | ||||
(-)-Pentazocine | 52.8 ± 3.0 | 89.3 ± 4.3 | 82.1 ± 3.7 | |
Morphine | 88.0 ± 3.1 | 83.7 ± 2.7 | 84.3 ± 3.3 | |