Table 1.
H1 and H3 receptor affinity values and binding kinetics for unlabelled antagonists
| Antagonist | Receptor | kon (mol·min−1) | koff (min−1) | t1/2 (min) | pKD | pKi |
|---|---|---|---|---|---|---|
| GSK1004723 | H1 | 7.33 ± 0.13 × 107 | 0.009 ± 0.002 | 73 | 9.91 ± 0.05 | 10.2 ± 0.24 |
| Mepyramine | H1 | 1.11 ± 0.23 × 109 | 0.817 ± 0.046 | 0.9 | 9.04 ± 0.10 | 8.86 ± 0.05 |
| GSK1004723 | H3 | 4.76 ± 0.69 × 108 | 0.007 ± 0.001 | 89 | 10.8 ± 0.12 | 10.6 ± 0.03 |
| GSK189254 | H3 | 3.04 ± 0.14 × 109 | 0.802 ± 0.010 | 0.9 | 9.58 ± 0.01 | 9.49 ± 0.07 |
Derived kinetic values were calculated by globally fitting experimental data generated at 37°C to the Motulsky and Mahan (1984) model. Dissociation t1/2 were calculated from koff values and KD (shown as negative log, pKD) calculated from koff/kon values as described under Data analysis and statistics. Ki (shown as negative log, pKi) calculated from IC50 values determined under equilibrium conditions in competition binding experiments, using Cheng–Prusoff equation, as described under Data analysis and statistics. Data are means ± SEM for four separate determinations.