Table 3.
KB and affinity ratio values of esmethadone and reference NMDAR blockers
| NR1-2A | NR1-2B | NR1-2C | NR1-2D | |||||
|---|---|---|---|---|---|---|---|---|
| KB (µM) | Affinity ratio (%) | KB (µM) | Affinity ratio (%) | KB (µM) | Affinity ratio (%) | KB (µM) | Affinity ratio (%) | |
| Esmethadone | 8.9 | 51 | 6.1 | 74 | 4.5 | 100 | 7.8 | 58 |
| (±)-Ketamine | 4.3 | 11 | 1.1 | 42 | 0.46 | 100 | 1.4 | 33 |
| Memantine | 3.6 | 8 | 0.58 | 48 | 0.28 | 100 | 0.59 | 47 |
| Dextromethorphan | 9.6 | 13 | 1.9 | 63 | 1.2 | 100 | 6.7 | 18 |
| MK-801 | 0.11 | 44 | 0.048 | 100 | 0.14 | 34 | 0.15 | 32 |
Estimated KB values for five NMDAR channel blockers were obtained via FLIPR assay by L-glutamate concentration–response curves. An operational equation for allosteric modulators was used to estimate KB and % affinity ratio for all tested molecules [28]