EC50 and Emax values for BUP and SAM alone and in combination in stimulating the activation of GαoA, GαoB, and Gαz mediated by the MOR, KOR, and DOR
EC50 values are expressed in total molarity when BUP and SAM were combined. Data are the mean values ± S.E.M. from six determinations.
| GαoA | GαoB | Gαz | ||||
|---|---|---|---|---|---|---|
| EC50 | Emax | EC50 | Emax | EC50 | Emax | |
| nM | % | nM | % | nM | % | |
| MOR | ||||||
| DAMGO | 8.0 ± 0.50 | 100 | 7.7 ± 2.0 | 100 | 4.2 ± 0.25 | 100 |
| Morphine | 12 ± 0.50 | 100 ± 4.0 | 11 ± 1.0 | 100 ± 2.0 | 6.0 ± 1.0 | 100 ± 1.0 |
| BUP | 0.40 ± 0.10 | 87 ± 2.0 | 0.30 ± 0.080 | 89 ± 2.5 | 0.90 ± 0.020 | 92 ± 3.5 |
| SAM | 1.1 ± 0.40 | 29 ± 2.0 | 0.26 ± 0.040 | 27 ± 7.0 | 0.060 ± 0.030 | 33 ± 2.0 |
| 1:3 BUP/SAM | 0.80 ± 0.20 | 42 ± 2.0 | 0.15 ± 0.010 | 43 ± 7.0 | 0.10 ± 0.0050 | 52 ± 3.0 |
| Naloxone | >20,000 | NA | 19 ± 6.3 | 13 ± 0.57 | 27 ± 11 | 33 ± 3.0 |
| Naltrexone | >20,000 | NA | 1.6 ± 0.52 | 15 ± 1.2 | 0.40 ± 0.043 | 40 ± 1.5 |
| KOR | ||||||
| U50,488 | 2.1 ± 0.050 | 100 | 0.80 ± 0.070 | 100 | 0.45 ± 0.14 | 100 |
| Morphine | 610 ± 29 | 98 ± 2.0 | 200 ± 44 | 98 ± 3.0 | 18 ± 1.5 | 94 ± 6.0 |
| BUP | 0.90 ± 0.40 | 35 ± 3.0 | 0.61 ± 0.19 | 66 ± 4.0 | 0.76 ± 0.080 | 104 ± 6.0 |
| SAM | 2.4 ± 0.60 | 61 ± 2.5 | 1.0 ± 0.10 | 86 ± 4.0 | 0.22 ± 0.050 | 95 ± 1.0 |
| 1:3 BUP/SAM | 0.90 ± 0.14 | 35 ± 2.0 | 0.63 ± 0.090 | 64 ± 5.0 | 0.16 ± 0.010 | 85 ± 2.0 |
| DOR | ||||||
| SNC-80 | 0.70 ± 0.020 | 100 | 1.1 ± 0.10 | 100 | 0.30 ± 0.10 | 100 |
| Morphine | >1 μM | ∼80 | 3300 ± 1700 | 93 ± 5.0 | 340 ± 29 | 87 ± 1.0 |
| BUP | 2.7 ± 0.60 | 56 ± 4.0 | 1.5 ± 0.40 | 65 ± 3.0 | 0.40 ± 0.10 | 79 ± 4.0 |
| SAM | 3.4 ± 0.50 | 27 ± 2.0 | 5.4 ± 0.30 | 48 ± 2.0 | 0.90 ± 0.10 | 69 ± 6.0 |
| 1:3 BUP/SAM | 5.7 ± 2.6 | 44 ± 4.0 | 2.9 ± 0.60 | 60 ± 2.0 | 0.60 ± 0.10 | 73 ± 5.0 |
NA, not applicable.