Receptor | Radioligand | Association | Dissociation | ||||
---|---|---|---|---|---|---|---|
k+1obb | k+1 | t½ | k−1 | t½ | Irr | ||
min−1 | min−1 · nM−1 | min | min−1 | min | %Bc | ||
hM3 | [3H]CHF5407 | 0.0116 ± 0.0011 | NC | 59.8 ± 10 | 0.0041 ± 0.0003 | 166.4 ± 13.0 | 54.02 ± 1.51 |
[3H]tiotropium | 0.0170 ± 0.0014 | NC | 40.8 ± 6.5 | 0.0053 ± 0.0013 | 163.3 ± 77.0 | 65.22 ± 12.41 | |
hM2 | [3H]CHF5407 | 0.096 ± 0.0010 | 0.369 ± 0.04 | 7.2 ± 1.5 | 0.0224 ± 0.0067 | 31.8 ± 9.4 | 0 |
[3H]tiotropium | 0.048 ± 0.0005 | NC | 14.5 ± 2 | 0.0024 ± 0.0005 | 297.3 ± 63.0 | 14.45 ± 0.60 | |
hM1 | [3H]CHF-5407 | 0.014 ± 0.001 | NC | 49.9 ± 3.5 | 0.0016 ± 0.0006 | 354.4 ± 26.7 | 16.20 ± 8.32 |
[3H]tiotropium | 0.012 ± 0.0005 | NC | 58.8 ± 2.5 | 0.0019 ± 0.0001 | 353.4 ± 7.1 | 40.40 ± 1.27 |
k+1obb, association rate constant observed (k + 1 × [L] + k −1), where [L] is the radioligand concentration; κ+1, association rate constant; κ+1 value was not calculated for radioligands displaying an irreversible component; t½, time required for half association; κ−1, dissociation rate constant; t½, time required for half dissociation from the reversible binding component; Irr, irreversible binding component expressed as percentage of control binding; % Bc, percentage of control binding (samples without 10 μM cold N-methyl scopolamine addition); NC, not calculated.